Table of Contents ***************** GNU troff 1 Introduction 1.1 What Is `groff'? 1.2 History 1.3 `groff' Capabilities 1.4 Macro Packages 1.5 Preprocessors 1.6 Output Devices 1.7 Credits 2 Invoking `groff' 2.1 Options 2.2 Environment 2.3 Macro Directories 2.4 Font Directories 2.5 Paper Size 2.6 Invocation Examples 2.6.1 `grog' 3 Tutorial for Macro Users 3.1 Basics 3.2 Common Features 3.2.1 Paragraphs 3.2.2 Sections and Chapters 3.2.3 Headers and Footers 3.2.4 Page Layout 3.2.5 Displays 3.2.6 Footnotes and Annotations 3.2.7 Table of Contents 3.2.8 Indices 3.2.9 Paper Formats 3.2.10 Multiple Columns 3.2.11 Font and Size Changes 3.2.12 Predefined Strings 3.2.13 Preprocessor Support 3.2.14 Configuration and Customization 4 Macro Packages 4.1 `man' 4.1.1 Options 4.1.2 Usage 4.1.3 Macros to set fonts 4.1.4 Miscellaneous macros 4.1.5 Predefined strings 4.1.6 Preprocessors in `man' pages 4.1.7 Optional `man' extensions Custom headers and footers Ultrix-specific man macros Simple example 4.2 `mdoc' 4.3 `ms' 4.3.1 Introduction to `ms' 4.3.2 General structure of an `ms' document 4.3.3 Document control registers Margin Settings Text Settings Paragraph Settings Footnote Settings Miscellaneous Number Registers 4.3.4 Cover page macros 4.3.5 Body text 4.3.5.1 Paragraphs 4.3.5.2 Headings 4.3.5.3 Highlighting 4.3.5.4 Lists 4.3.5.5 Indentation values 4.3.5.6 Tab Stops 4.3.5.7 Displays and keeps 4.3.5.8 Tables, figures, equations, and references 4.3.5.9 An example multi-page table 4.3.5.10 Footnotes 4.3.6 Page layout 4.3.6.1 Headers and footers 4.3.6.2 Margins 4.3.6.3 Multiple columns 4.3.6.4 Creating a table of contents 4.3.6.5 Strings and Special Characters 4.3.7 Differences from AT&T `ms' 4.3.7.1 `troff' macros not appearing in `groff' 4.3.7.2 `groff' macros not appearing in AT&T `troff' 4.3.8 Naming Conventions 4.4 `me' 4.5 `mm' 4.6 `mom' 5 `gtroff' Reference 5.1 Text 5.1.1 Filling and Adjusting 5.1.2 Hyphenation 5.1.3 Sentences 5.1.4 Tab Stops 5.1.5 Implicit Line Breaks 5.1.6 Input Conventions 5.1.7 Input Encodings 5.2 Measurements 5.2.1 Default Units 5.3 Expressions 5.4 Identifiers 5.5 Embedded Commands 5.5.1 Requests 5.5.1.1 Request and Macro Arguments 5.5.2 Macros 5.5.3 Escapes 5.5.3.1 Comments 5.6 Registers 5.6.1 Setting Registers 5.6.2 Interpolating Registers 5.6.3 Auto-increment 5.6.4 Assigning Formats 5.6.5 Built-in Registers 5.7 Manipulating Filling and Adjusting 5.8 Manipulating Hyphenation 5.9 Manipulating Spacing 5.10 Tabs and Fields 5.10.1 Leaders 5.10.2 Fields 5.11 Character Translations 5.12 Troff and Nroff Mode 5.13 Line Layout 5.14 Line Control 5.15 Page Layout 5.16 Page Control 5.17 Fonts and Symbols 5.17.1 Changing Fonts 5.17.2 Font Families 5.17.3 Font Positions 5.17.4 Using Symbols 5.17.5 Character Classes 5.17.6 Special Fonts 5.17.7 Artificial Fonts 5.17.8 Ligatures and Kerning 5.18 Sizes 5.18.1 Changing Type Sizes 5.18.2 Fractional Type Sizes 5.19 Strings 5.20 Conditionals and Loops 5.20.1 Operators in Conditionals 5.20.2 if-else 5.20.3 while 5.21 Writing Macros 5.21.1 Copy-in Mode 5.21.2 Parameters 5.22 Page Motions 5.23 Drawing Requests 5.24 Traps 5.24.1 Page Location Traps 5.24.2 Diversion Traps 5.24.3 Input Line Traps 5.24.4 Blank Line Traps 5.24.5 Leading Spaces Traps 5.24.6 End-of-input Traps 5.25 Diversions 5.26 Environments 5.27 Suppressing output 5.28 Colors 5.29 I/O 5.30 Postprocessor Access 5.31 Miscellaneous 5.32 `gtroff' Internals 5.33 Debugging 5.33.1 Warnings 5.34 Implementation Differences 6 Preprocessors 6.1 `geqn' 6.1.1 Invoking `geqn' 6.2 `gtbl' 6.2.1 Invoking `gtbl' 6.3 `gpic' 6.3.1 Invoking `gpic' 6.4 `ggrn' 6.4.1 Invoking `ggrn' 6.5 `grap' 6.6 `gchem' 6.6.1 Invoking `gchem' 6.7 `grefer' 6.7.1 Invoking `grefer' 6.8 `gsoelim' 6.8.1 Invoking `gsoelim' 6.9 `preconv' 6.9.1 Invoking `preconv' 7 Output Devices 7.1 Special Characters 7.2 `grotty' 7.2.1 Invoking `grotty' 7.3 `grops' 7.3.1 Invoking `grops' 7.3.2 Embedding POSTSCRIPT 7.4 `gropdf' 7.4.1 Invoking `gropdf' 7.4.2 Embedding PDF 7.5 `grodvi' 7.5.1 Invoking `grodvi' 7.6 `grolj4' 7.6.1 Invoking `grolj4' 7.7 `grolbp' 7.7.1 Invoking `grolbp' 7.8 `grohtml' 7.8.1 Invoking `grohtml' 7.8.2 `grohtml' specific registers and strings 7.9 `gxditview' 7.9.1 Invoking `gxditview' 8 File formats 8.1 `gtroff' Output 8.1.1 Language Concepts 8.1.1.1 Separation 8.1.1.2 Argument Units 8.1.1.3 Document Parts 8.1.2 Command Reference 8.1.2.1 Comment Command 8.1.2.2 Simple Commands 8.1.2.3 Graphics Commands 8.1.2.4 Device Control Commands 8.1.2.5 Obsolete Command 8.1.3 Intermediate Output Examples 8.1.4 Output Language Compatibility 8.2 Font Files 8.2.1 `DESC' File Format 8.2.2 Font File Format 9 Installation Appendix A Copying This Manual Appendix B Request Index Appendix C Escape Index Appendix D Operator Index Appendix E Register Index Appendix F Macro Index Appendix G String Index Appendix H Glyph Name Index Appendix I Font File Keyword Index Appendix J Program and File Index Appendix K Concept Index GNU troff ********* This manual documents GNU `troff' version 1.22.2. Copyright (C) 1994-2013 Free Software Foundation, Inc. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.3 or any later version published by the Free Software Foundation; with no Invariant Sections, with the Front-Cover texts being `A GNU Manual," and with the Back-Cover Texts as in (a) below. A copy of the license is included in the section entitled `GNU Free Documentation License." (a) The FSF's Back-Cover Text is: "You have the freedom to copy and modify this GNU manual. Buying copies from the FSF supports it in developing GNU and promoting software freedom." 1 Introduction ************** GNU `troff' (or `groff') is a system for typesetting documents. `troff' is very flexible and has been used extensively for some thirty years. It is well entrenched in the UNIX community. 1.1 What Is `groff'? ==================== `groff' belongs to an older generation of document preparation systems, which operate more like compilers than the more recent interactive WYSIWYG(1) (*note What Is groff?-Footnote-1::) systems. `groff' and its contemporary counterpart, TeX, both work using a "batch" paradigm: The input (or "source") files are normal text files with embedded formatting commands. These files can then be processed by `groff' to produce a typeset document on a variety of devices. `groff' should not be confused with a "word processor", an integrated system of editor and text formatter. Also, many word processors follow the WYSIWYG paradigm discussed earlier. Although WYSIWYG systems may be easier to use, they have a number of disadvantages compared to `troff': * They must be used on a graphics display to work on a document. * Most of the WYSIWYG systems are either non-free or are not very portable. * `troff' is firmly entrenched in all UNIX systems. * It is difficult to have a wide range of capabilities within the confines of a GUI/window system. * It is more difficult to make global changes to a document. "GUIs normally make it simple to accomplish simple actions and impossible to accomplish complex actions." -Doug Gwyn (22/Jun/91 in `comp.unix.wizards') (1) What You See Is What You Get 1.2 History =========== `troff' can trace its origins back to a formatting program called `RUNOFF', written by Jerry Saltzer, which ran on the CTSS (_Compatible Time Sharing System_, a project of MIT, the Massachusetts Institute of Technology) in the mid-sixties.(1) (*note History-Footnote-1::) The name came from the use of the phrase "run off a document", meaning to print it out. Bob Morris ported it to the 635 architecture and called the program `roff' (an abbreviation of `runoff'). It was rewritten as `rf' for the PDP-7 (before having UNIX), and at the same time (1969), Doug McIllroy rewrote an extended and simplified version of `roff' in the BCPL programming language. In 1971, the UNIX developers wanted to get a PDP-11, and to justify the cost, proposed the development of a document formatting system for the AT&T patents division. This first formatting program was a reimplementation of McIllroy's `roff', written by J. F. Ossanna. When they needed a more flexible language, a new version of `roff' called `nroff' ("Newer `roff'") was written. It had a much more complicated syntax, but provided the basis for all future versions. When they got a Graphic Systems CAT Phototypesetter, Ossanna wrote a version of `nroff' that would drive it. It was dubbed `troff', for "typesetter `roff'", although many people have speculated that it actually means "Times `roff'" because of the use of the Times font family in `troff' by default. As such, the name `troff' is pronounced `t-roff' rather than `trough'. With `troff' came `nroff' (they were actually the same program except for some `#ifdef's), which was for producing output for line printers and character terminals. It understood everything `troff' did, and ignored the commands which were not applicable (e.g. font changes). Since there are several things which cannot be done easily in `troff', work on several preprocessors began. These programs would transform certain parts of a document into `troff', which made a very natural use of pipes in UNIX. The `eqn' preprocessor allowed mathematical formulæ to be specified in a much simpler and more intuitive manner. `tbl' is a preprocessor for formatting tables. The `refer' preprocessor (and the similar program, `bib') processes citations in a document according to a bibliographic database. Unfortunately, Ossanna's `troff' was written in PDP-11 assembly language and produced output specifically for the CAT phototypesetter. He rewrote it in C, although it was now 7000 lines of uncommented code and still dependent on the CAT. As the CAT became less common, and was no longer supported by the manufacturer, the need to make it support other devices became a priority. However, before this could be done, Ossanna died by a severe heart attack in a hospital while recovering from a previous one. So, Brian Kernighan took on the task of rewriting `troff'. The newly rewritten version produced device independent code which was very easy for postprocessors to read and translate to the appropriate printer codes. Also, this new version of `troff' (called `ditroff' for "device independent `troff'") had several extensions, which included drawing functions. Due to the additional abilities of the new version of `troff', several new preprocessors appeared. The `pic' preprocessor provides a wide range of drawing functions. Likewise the `ideal' preprocessor did the same, although via a much different paradigm. The `grap' preprocessor took specifications for graphs, but, unlike other preprocessors, produced `pic' code. James Clark began work on a GNU implementation of `ditroff' in early 1989. The first version, `groff' 0.3.1, was released June 1990. `groff' included: * A replacement for `ditroff' with many extensions. * The `soelim', `pic', `tbl', and `eqn' preprocessors. * Postprocessors for character devices, POSTSCRIPT, TeX DVI, and X Windows. GNU `troff' also eliminated the need for a separate `nroff' program with a postprocessor which would produce ASCII output. * A version of the `me' macros and an implementation of the `man' macros. Also, a front-end was included which could construct the, sometimes painfully long, pipelines required for all the post- and preprocessors. Development of GNU `troff' progressed rapidly, and saw the additions of a replacement for `refer', an implementation of the `ms' and `mm' macros, and a program to deduce how to format a document (`grog'). It was declared a stable (i.e. non-beta) package with the release of version 1.04 around November 1991. Beginning in 1999, `groff' has new maintainers (the package was an orphan for a few years). As a result, new features and programs like `grn', a preprocessor for gremlin images, and an output device to produce HTML and XHTML have been added. (1) Jerome H. Saltzer, a grad student then, later a Professor of Electrical Engineering, now retired. Saltzer's PhD thesis was the first application for `RUNOFF' and is available from the MIT Libraries. 1.3 `groff' Capabilities ======================== So what exactly is `groff' capable of doing? `groff' provides a wide range of low-level text formatting operations. Using these, it is possible to perform a wide range of formatting tasks, such as footnotes, table of contents, multiple columns, etc. Here's a list of the most important operations supported by `groff': * text filling, adjusting, and centering * hyphenation * page control * font and glyph size control * vertical spacing (e.g. double-spacing) * line length and indenting * macros, strings, diversions, and traps * number registers * tabs, leaders, and fields * input and output conventions and character translation * overstrike, bracket, line drawing, and zero-width functions * local horizontal and vertical motions and the width function * three-part titles * output line numbering * conditional acceptance of input * environment switching * insertions from the standard input * input/output file switching * output and error messages 1.4 Macro Packages ================== Since `groff' provides such low-level facilities, it can be quite difficult to use by itself. However, `groff' provides a "macro" facility to specify how certain routine operations (e.g. starting paragraphs, printing headers and footers, etc.) should be done. These macros can be collected together into a "macro package". There are a number of macro packages available; the most common (and the ones described in this manual) are `man', `mdoc', `me', `ms', and `mm'. 1.5 Preprocessors ================= Although `groff' provides most functions needed to format a document, some operations would be unwieldy (e.g. to draw pictures). Therefore, programs called "preprocessors" were written which understand their own language and produce the necessary `groff' operations. These preprocessors are able to differentiate their own input from the rest of the document via markers. To use a preprocessor, UNIX pipes are used to feed the output from the preprocessor into `groff'. Any number of preprocessors may be used on a given document; in this case, the preprocessors are linked together into one pipeline. However, with `groff', the user does not need to construct the pipe, but only tell `groff' what preprocessors to use. `groff' currently has preprocessors for producing tables (`tbl'), typesetting equations (`eqn'), drawing pictures (`pic' and `grn'), processing bibliographies (`refer'), and drawing chemical structures (`chem'). An associated program which is useful when dealing with preprocessors is `soelim'. A free implementation of `grap', a preprocessor for drawing graphs, can be obtained as an extra package; `groff' can use `grap' also. Unique to `groff' is the `preconv' preprocessor which enables `groff' to handle documents in various input encodings. There are other preprocessors in existence, but, unfortunately, no free implementations are available. Among them is a preprocessor for drawing mathematical pictures (`ideal'). 1.6 Output Devices ================== `groff' actually produces device independent code which may be fed into a postprocessor to produce output for a particular device. Currently, `groff' has postprocessors for POSTSCRIPT devices, character terminals, X Windows (for previewing), TeX DVI format, HP LaserJet 4 and Canon LBP printers (which use CAPSL), HTML, XHTML, and PDF. 1.7 Credits =========== Large portions of this manual were taken from existing documents, most notably, the manual pages for the `groff' package by James Clark, and Eric Allman's papers on the `me' macro package. The section on the `man' macro package is partly based on Susan G. Kleinmann's `groff_man' manual page written for the Debian GNU/Linux system. Larry Kollar contributed the section in the `ms' macro package. 2 Invoking `groff' ****************** This section focuses on how to invoke the `groff' front end. This front end takes care of the details of constructing the pipeline among the preprocessors, `gtroff' and the postprocessor. It has become a tradition that GNU programs get the prefix `g' to distinguish it from its original counterparts provided by the host (see *note Environment::, for more details). Thus, for example, `geqn' is GNU `eqn'. On operating systems like GNU/Linux or the Hurd, which don't contain proprietary versions of `troff', and on MS-DOS/MS-Windows, where `troff' and associated programs are not available at all, this prefix is omitted since GNU `troff' is the only used incarnation of `troff'. Exception: `groff' is never replaced by `roff'. In this document, we consequently say `gtroff' when talking about the GNU `troff' program. All other implementations of `troff' are called AT&T `troff' which is the common origin of all `troff' derivates (with more or less compatible changes). Similarly, we say `gpic', `geqn', etc. 2.1 Options =========== `groff' normally runs the `gtroff' program and a postprocessor appropriate for the selected device. The default device is `ps' (but it can be changed when `groff' is configured and built). It can optionally preprocess with any of `gpic', `geqn', `gtbl', `ggrn', `grap', `gchem', `grefer', `gsoelim', or `preconv'. This section only documents options to the `groff' front end. Many of the arguments to `groff' are passed on to `gtroff', therefore those are also included. Arguments to pre- or postprocessors can be found in *note Invoking gpic::, *note Invoking geqn::, *note Invoking gtbl::, *note Invoking ggrn::, *note Invoking grefer::, *note Invoking gchem::, *note Invoking gsoelim::, *note Invoking preconv::, *note Invoking grotty::, *note Invoking grops::, *note Invoking gropdf::, *note Invoking grohtml::, *note Invoking grodvi::, *note Invoking grolj4::, *note Invoking grolbp::, and *note Invoking gxditview::. The command line format for `groff' is: groff [ -abceghijklpstvzCEGNRSUVXZ ] [ -dCS ] [ -DARG ] [ -fFAM ] [ -FDIR ] [ -IDIR ] [ -KARG ] [ -LARG ] [ -mNAME ] [ -MDIR ] [ -nNUM ] [ -oLIST ] [ -PARG ] [ -rCN ] [ -TDEF ] [ -wNAME ] [ -WNAME ] [ FILES... ] The command line format for `gtroff' is as follows. gtroff [ -abcivzCERU ] [ -dCS ] [ -fFAM ] [ -FDIR ] [ -mNAME ] [ -MDIR ] [ -nNUM ] [ -oLIST ] [ -rCN ] [ -TNAME ] [ -wNAME ] [ -WNAME ] [ FILES... ] Obviously, many of the options to `groff' are actually passed on to `gtroff'. Options without an argument can be grouped behind a single `-'. A filename of `-' denotes the standard input. It is possible to have whitespace between an option and its parameter. The `grog' command can be used to guess the correct `groff' command to format a file. Here's the description of the command-line options: `-a' Generate an ASCII approximation of the typeset output. The read-only register `.A' is then set to 1. *Note Built-in Registers::. A typical example is groff -a -man -Tdvi troff.man | less which shows how lines are broken for the DVI device. Note that this option is rather useless today since graphic output devices are available virtually everywhere. `-b' Print a backtrace with each warning or error message. This backtrace should help track down the cause of the error. The line numbers given in the backtrace may not always be correct: `gtroff' can get confused by `as' or `am' requests while counting line numbers. `-c' Suppress color output. `-C' Enable compatibility mode. *Note Implementation Differences::, for the list of incompatibilities between `groff' and AT&T `troff'. `-dCS' `-dNAME=S' Define C or NAME to be a string S. C must be a one-letter name; NAME can be of arbitrary length. All string assignments happen before loading any macro file (including the start-up file). `-DARG' Set default input encoding used by `preconv' to ARG. Implies `-k'. `-e' Preprocess with `geqn'. `-E' Inhibit all error messages. `-fFAM' Use FAM as the default font family. *Note Font Families::. `-FDIR' Search `DIR' for subdirectories `devNAME' (NAME is the name of the device), for the `DESC' file, and for font files before looking in the standard directories (*note Font Directories::). This option is passed to all pre- and postprocessors using the `GROFF_FONT_PATH' environment variable. `-g' Preprocess with `ggrn'. `-G' Preprocess with `grap'. Implies `-p'. `-h' Print a help message. `-i' Read the standard input after all the named input files have been processed. `-IDIR' This option may be used to specify a directory to search for files. It is passed to the following programs: * `gsoelim' (see *note gsoelim:: for more details); it also implies `groff''s `-s' option. * `gtroff'; it is used to search files named in the `psbb' and `so' requests. * `grops'; it is used to search files named in the `\X'ps: import' and `\X'ps: file' escapes. The current directory is always searched first. This option may be specified more than once; the directories are searched in the order specified. No directory search is performed for files specified using an absolute path. `-j' Preprocess with `gchem'. Implies `-p'. `-k' Preprocess with `preconv'. This is run before any other preprocessor. Please refer to `preconv''s manual page for its behaviour if no `-K' (or `-D') option is specified. `-KARG' Set input encoding used by preconv to ARG. Implies `-k'. `-l' Send the output to a spooler for printing. The command used for this is specified by the `print' command in the device description file (see *note Font Files::, for more info). If not present, `-l' is ignored. `-LARG' Pass ARG to the spooler. Each argument should be passed with a separate `-L' option. Note that `groff' does not prepend a `-' to ARG before passing it to the postprocessor. If the `print' keyword in the device description file is missing, `-L' is ignored. `-mNAME' Read in the file `NAME.tmac'. Normally `groff' searches for this in its macro directories. If it isn't found, it tries `tmac.NAME' (searching in the same directories). `-MDIR' Search directory `DIR' for macro files before the standard directories (*note Macro Directories::). `-nNUM' Number the first page NUM. `-N' Don't allow newlines with `eqn' delimiters. This is the same as the `-N' option in `geqn'. `-oLIST' Output only pages in LIST, which is a comma-separated list of page ranges; `N' means print page N, `M-N' means print every page between M and N, `-N' means print every page up to N, `N-' means print every page beginning with N. `gtroff' exits after printing the last page in the list. All the ranges are inclusive on both ends. Within `gtroff', this information can be extracted with the `.P' register. *Note Built-in Registers::. If your document restarts page numbering at the beginning of each chapter, then `gtroff' prints the specified page range for each chapter. `-p' Preprocess with `gpic'. `-PARG' Pass ARG to the postprocessor. Each argument should be passed with a separate `-P' option. Note that `groff' does not prepend `-' to ARG before passing it to the postprocessor. `-rCN' `-rNAME=N' Set number register C or NAME to the value N. C must be a one-letter name; NAME can be of arbitrary length. N can be any `gtroff' numeric expression. All register assignments happen before loading any macro file (including the start-up file). `-R' Preprocess with `grefer'. No mechanism is provided for passing arguments to `grefer' because most `grefer' options have equivalent commands which can be included in the file. *Note grefer::, for more details. Note that `gtroff' also accepts a `-R' option, which is not accessible via `groff'. This option prevents the loading of the `troffrc' and `troffrc-end' files. `-s' Preprocess with `gsoelim'. `-S' Safer mode. Pass the `-S' option to `gpic' and disable the `open', `opena', `pso', `sy', and `pi' requests. For security reasons, this is enabled by default. `-t' Preprocess with `gtbl'. `-TDEV' Prepare output for device DEV. The default device is `ps', unless changed when `groff' was configured and built. The following are the output devices currently available: `ps' For POSTSCRIPT printers and previewers. `pdf' For PDF viewers or printers. `dvi' For TeX DVI format. `X75' For a 75dpi X11 previewer. `X75-12' For a 75dpi X11 previewer with a 12pt base font in the document. `X100' For a 100dpi X11 previewer. `X100-12' For a 100dpi X11 previewer with a 12pt base font in the document. `ascii' For typewriter-like devices using the (7-bit) ASCII character set. `latin1' For typewriter-like devices that support the Latin-1 (ISO 8859-1) character set. `utf8' For typewriter-like devices which use the Unicode (ISO 10646) character set with UTF-8 encoding. `cp1047' For typewriter-like devices which use the EBCDIC encoding IBM cp1047. `lj4' For HP LaserJet4-compatible (or other PCL5-compatible) printers. `lbp' For Canon CAPSL printers (LBP-4 and LBP-8 series laser printers). `html' `xhtml' To produce HTML and XHTML output, respectively. Note that this driver consists of two parts, a preprocessor (`pre-grohtml') and a postprocessor (`post-grohtml'). The predefined `gtroff' string register `.T' contains the current output device; the read-only number register `.T' is set to 1 if this option is used (which is always true if `groff' is used to call `gtroff'). *Note Built-in Registers::. The postprocessor to be used for a device is specified by the `postpro' command in the device description file. (*Note Font Files::, for more info.) This can be overridden with the `-X' option. `-U' Unsafe mode. This enables the `open', `opena', `pso', `sy', and `pi' requests. `-wNAME' Enable warning NAME. Available warnings are described in *note Debugging::. Multiple `-w' options are allowed. `-WNAME' Inhibit warning NAME. Multiple `-W' options are allowed. `-v' Make programs run by `groff' print out their version number. `-V' Print the pipeline on `stdout' instead of executing it. If specified more than once, print the pipeline on `stderr' and execute it. `-X' Preview with `gxditview' instead of using the usual postprocessor. This is unlikely to produce good results except with `-Tps'. Note that this is not the same as using `-TX75' or `-TX100' to view a document with `gxditview': The former uses the metrics of the specified device, whereas the latter uses X-specific fonts and metrics. `-z' Suppress output from `gtroff'. Only error messages are printed. `-Z' Do not postprocess the output of `gtroff'. Normally `groff' automatically runs the appropriate postprocessor. 2.2 Environment =============== There are also several environment variables (of the operating system, not within `gtroff') which can modify the behavior of `groff'. `GROFF_BIN_PATH' This search path, followed by `PATH', is used for commands executed by `groff'. `GROFF_COMMAND_PREFIX' If this is set to X, then `groff' runs `Xtroff' instead of `gtroff'. This also applies to `tbl', `pic', `eqn', `grn', `chem', `refer', and `soelim'. It does not apply to `grops', `grodvi', `grotty', `pre-grohtml', `post-grohtml', `preconv', `grolj4', `gropdf', and `gxditview'. The default command prefix is determined during the installation process. If a non-GNU troff system is found, prefix `g' is used, none otherwise. `GROFF_ENCODING' The value of this environment value is passed to the `preconv' preprocessor to select the encoding of input files. Setting this option implies `groff''s command line option `-k' (this is, `groff' actually always calls `preconv'). If set without a value, `groff' calls `preconv' without arguments. An explicit `-K' command line option overrides the value of `GROFF_ENCODING'. See the manual page of `preconv' for details. `GROFF_FONT_PATH' A colon-separated list of directories in which to search for the `dev'NAME directory (before the default directories are tried). *Note Font Directories::. `GROFF_TMAC_PATH' A colon-separated list of directories in which to search for macro files (before the default directories are tried). *Note Macro Directories::. `GROFF_TMPDIR' The directory in which `groff' creates temporary files. If this is not set and `TMPDIR' is set, temporary files are created in that directory. Otherwise temporary files are created in a system-dependent default directory (on Unix and GNU/Linux systems, this is usually `/tmp'). `grops', `grefer', `pre-grohtml', and `post-grohtml' can create temporary files in this directory. `GROFF_TYPESETTER' The default output device. Note that MS-DOS and MS-Windows ports of `groff' use semi-colons, rather than colons, to separate the directories in the lists described above. 2.3 Macro Directories ===================== All macro file names must be named `NAME.tmac' or `tmac.NAME' to make the `-mNAME' command line option work. The `mso' request doesn't have this restriction; any file name can be used, and `gtroff' won't try to append or prepend the `tmac' string. Macro files are kept in the "tmac directories", all of which constitute the "tmac path". The elements of the search path for macro files are (in that order): * The directories specified with `gtroff''s or `groff''s `-M' command line option. * The directories given in the `GROFF_TMAC_PATH' environment variable. * The current directory (only if in unsafe mode using the `-U' command line switch). * The home directory. * A platform-dependent directory, a site-specific (platform-independent) directory, and the main tmac directory; the default locations are /usr/local/lib/groff/site-tmac /usr/local/share/groff/site-tmac /usr/local/share/groff/1.22.2/tmac assuming that the version of `groff' is 1.22.2, and the installation prefix was `/usr/local'. It is possible to fine-tune those directories during the installation process. 2.4 Font Directories ==================== Basically, there is no restriction how font files for `groff' are named and how long font names are; however, to make the font family mechanism work (*note Font Families::), fonts within a family should start with the family name, followed by the shape. For example, the Times family uses `T' for the family name and `R', `B', `I', and `BI' to indicate the shapes `roman', `bold', `italic', and `bold italic', respectively. Thus the final font names are `TR', `TB', `TI', and `TBI'. All font files are kept in the "font directories" which constitute the "font path". The file search functions always append the directory `dev'NAME, where NAME is the name of the output device. Assuming, say, DVI output, and `/foo/bar' as a font directory, the font files for `grodvi' must be in `/foo/bar/devdvi'. The elements of the search path for font files are (in that order): * The directories specified with `gtroff''s or `groff''s `-F' command line option. All device drivers and some preprocessors also have this option. * The directories given in the `GROFF_FONT_PATH' environment variable. * A site-specific directory and the main font directory; the default locations are /usr/local/share/groff/site-font /usr/local/share/groff/1.22.2/font assuming that the version of `groff' is 1.22.2, and the installation prefix was `/usr/local'. It is possible to fine-tune those directories during the installation process. 2.5 Paper Size ============== In groff, the page size for `gtroff' and for output devices are handled separately. *Note Page Layout::, for vertical manipulation of the page size. *Note Line Layout::, for horizontal changes. A default paper size can be set in the device's `DESC' file. Most output devices also have a command line option `-p' to override the default paper size and option `-l' to use landscape orientation. *Note DESC File Format::, for a description of the `papersize' keyword which takes the same argument as `-p'. A convenient shorthand to set a particular paper size for `gtroff' is command line option `-dpaper=SIZE'. This defines string `paper' which is processed in file `papersize.tmac' (loaded in the start-up file `troffrc' by default). Possible values for SIZE are the same as the predefined values for the `papersize' keyword (but only in lowercase) except `a7'-`d7'. An appended `l' (ell) character denotes landscape orientation. For example, use the following for PS output on A4 paper in landscape orientation: groff -Tps -dpaper=a4l -P-pa4 -P-l -ms foo.ms > foo.ps Note that it is up to the particular macro package to respect default page dimensions set in this way (most do). 2.6 Invocation Examples ======================= This section lists several common uses of `groff' and the corresponding command lines. groff file This command processes `file' without a macro package or a preprocessor. The output device is the default, `ps', and the output is sent to `stdout'. groff -t -mandoc -Tascii file | less This is basically what a call to the `man' program does. `gtroff' processes the manual page `file' with the `mandoc' macro file (which in turn either calls the `man' or the `mdoc' macro package), using the `tbl' preprocessor and the ASCII output device. Finally, the `less' pager displays the result. groff -X -m me file Preview `file' with `gxditview', using the `me' macro package. Since no `-T' option is specified, use the default device (`ps'). Note that you can either say `-m me' or `-me'; the latter is an anachronism from the early days of UNIX.(1) (*note Invocation Examples-Footnote-1::) groff -man -rD1 -z file Check `file' with the `man' macro package, forcing double-sided printing - don't produce any output. (1) The same is true for the other main macro packages that come with `groff': `man', `mdoc', `ms', `mm', and `mandoc'. This won't work in general; for example, to load `trace.tmac', either `-mtrace' or `-m trace' must be used. 2.6.1 `grog' ------------ `grog' reads files, guesses which of the `groff' preprocessors and/or macro packages are required for formatting them, and prints the `groff' command including those options on the standard output. It generates one or more of the options `-e', `-man', `-me', `-mm', `-mom', `-ms', `-mdoc', `-mdoc-old', `-p', `-R', `-g', `-G', `-s', and `-t'. A special file name `-' refers to the standard input. Specifying no files also means to read the standard input. Any specified options are included in the printed command. No space is allowed between options and their arguments. The only options recognized are `-C' (which is also passed on) to enable compatibility mode, and `-v' to print the version number and exit. For example, grog -Tdvi paper.ms guesses the appropriate command to print `paper.ms' and then prints it to the command line after adding the `-Tdvi' option. For direct execution, enclose the call to `grog' in backquotes at the UNIX shell prompt: `grog -Tdvi paper.ms` > paper.dvi As seen in the example, it is still necessary to redirect the output to something meaningful (i.e. either a file or a pager program like `less'). 3 Tutorial for Macro Users ************************** Most users tend to use a macro package to format their papers. This means that the whole breadth of `groff' is not necessary for most people. This chapter covers the material needed to efficiently use a macro package. 3.1 Basics ========== This section covers some of the basic concepts necessary to understand how to use a macro package.(1) (*note Basics-Footnote-1::) References are made throughout to more detailed information, if desired. `gtroff' reads an input file prepared by the user and outputs a formatted document suitable for publication or framing. The input consists of text, or words to be printed, and embedded commands ("requests" and "escapes"), which tell `gtroff' how to format the output. For more detail on this, see *note Embedded Commands::. The word "argument" is used in this chapter to mean a word or number which appears on the same line as a request, and which modifies the meaning of that request. For example, the request .sp spaces one line, but .sp 4 spaces four lines. The number 4 is an argument to the `sp' request which says to space four lines instead of one. Arguments are separated from the request and from each other by spaces (_no_ tabs). More details on this can be found in *note Request and Macro Arguments::. The primary function of `gtroff' is to collect words from input lines, fill output lines with those words, justify the right-hand margin by inserting extra spaces in the line, and output the result. For example, the input: Now is the time for all good men to come to the aid of their party. Four score and seven years ago, etc. is read, packed onto output lines, and justified to produce: Now is the time for all good men to come to the aid of their party. Four score and seven years ago, etc. Sometimes a new output line should be started even though the current line is not yet full; for example, at the end of a paragraph. To do this it is possible to cause a "break", which starts a new output line. Some requests cause a break automatically, as normally do blank input lines and input lines beginning with a space. Not all input lines are text to be formatted. Some input lines are requests which describe how to format the text. Requests always have a period (`.') or an apostrophe (`'') as the first character of the input line. The text formatter also does more complex things, such as automatically numbering pages, skipping over page boundaries, putting footnotes in the correct place, and so forth. Here are a few hints for preparing text for input to `gtroff'. * First, keep the input lines short. Short input lines are easier to edit, and `gtroff' packs words onto longer lines anyhow. * In keeping with this, it is helpful to begin a new line after every comma or phrase, since common corrections are to add or delete sentences or phrases. * End each sentence with two spaces - or better, start each sentence on a new line. `gtroff' recognizes characters that usually end a sentence, and inserts sentence space accordingly. * Do not hyphenate words at the end of lines - `gtroff' is smart enough to hyphenate words as needed, but is not smart enough to take hyphens out and join a word back together. Also, words such as "mother-in-law" should not be broken over a line, since then a space can occur where not wanted, such as "mother- in-law". `gtroff' double-spaces output text automatically if you use the request `.ls 2'. Reactivate single-spaced mode by typing `.ls 1'.(2) (*note Basics-Footnote-2::) A number of requests allow to change the way the output looks, sometimes called the "layout" of the output page. Most of these requests adjust the placing of "whitespace" (blank lines or spaces). The `bp' request starts a new page, causing a line break. The request `.sp N' leaves N lines of blank space. N can be omitted (meaning skip a single line) or can be of the form Ni (for N inches) or Nc (for N centimeters). For example, the input: .sp 1.5i My thoughts on the subject .sp leaves one and a half inches of space, followed by the line "My thoughts on the subject", followed by a single blank line (more measurement units are available, see *note Measurements::). Text lines can be centered by using the `ce' request. The line after `ce' is centered (horizontally) on the page. To center more than one line, use `.ce N' (where N is the number of lines to center), followed by the N lines. To center many lines without counting them, type: .ce 1000 lines to center .ce 0 The `.ce 0' request tells `groff' to center zero more lines, in other words, stop centering. All of these requests cause a break; that is, they always start a new line. To start a new line without performing any other action, use `br'. (1) This section is derived from `Writing Papers with nroff using -me' by Eric P. Allman. (2) If you need finer granularity of the vertical space, use the `pvs' request (*note Changing Type Sizes::). 3.2 Common Features =================== `gtroff' provides very low-level operations for formatting a document. There are many common routine operations which are done in all documents. These common operations are written into "macros" and collected into a "macro package". All macro packages provide certain common capabilities which fall into the following categories. 3.2.1 Paragraphs ---------------- One of the most common and most used capability is starting a paragraph. There are a number of different types of paragraphs, any of which can be initiated with macros supplied by the macro package. Normally, paragraphs start with a blank line and the first line indented, like the text in this manual. There are also block style paragraphs, which omit the indentation: Some men look at constitutions with sanctimonious reverence, and deem them like the ark of the covenant, too sacred to be touched. And there are also indented paragraphs which begin with a tag or label at the margin and the remaining text indented. one This is the first paragraph. Notice how the first line of the resulting paragraph lines up with the other lines in the paragraph. longlabel This paragraph had a long label. The first character of text on the first line does not line up with the text on second and subsequent lines, although they line up with each other. A variation of this is a bulleted list. . Bulleted lists start with a bullet. It is possible to use other glyphs instead of the bullet. In nroff mode using the ASCII character set for output, a dot is used instead of a real bullet. 3.2.2 Sections and Chapters --------------------------- Most macro packages supply some form of section headers. The simplest kind is simply the heading on a line by itself in bold type. Others supply automatically numbered section heading or different heading styles at different levels. Some, more sophisticated, macro packages supply macros for starting chapters and appendices. 3.2.3 Headers and Footers ------------------------- Every macro package gives some way to manipulate the "headers" and "footers" (also called "titles") on each page. This is text put at the top and bottom of each page, respectively, which contain data like the current page number, the current chapter title, and so on. Its appearance is not affected by the running text. Some packages allow for different ones on the even and odd pages (for material printed in a book form). The titles are called "three-part titles", that is, there is a left-justified part, a centered part, and a right-justified part. An automatically generated page number may be put in any of these fields with the `%' character (see *note Page Layout::, for more details). 3.2.4 Page Layout ----------------- Most macro packages let the user specify top and bottom margins and other details about the appearance of the printed pages. 3.2.5 Displays -------------- "Displays" are sections of text to be set off from the body of the paper. Major quotes, tables, and figures are types of displays, as are all the examples used in this document. "Major quotes" are quotes which are several lines long, and hence are set in from the rest of the text without quote marks around them. A "list" is an indented, single-spaced, unfilled display. Lists should be used when the material to be printed should not be filled and justified like normal text, such as columns of figures or the examples used in this paper. A "keep" is a display of lines which are kept on a single page if possible. An example for a keep might be a diagram. Keeps differ from lists in that lists may be broken over a page boundary whereas keeps are not. "Floating keeps" move relative to the text. Hence, they are good for things which are referred to by name, such as "See figure 3". A floating keep appears at the bottom of the current page if it fits; otherwise, it appears at the top of the next page. Meanwhile, the surrounding text `flows' around the keep, thus leaving no blank areas. 3.2.6 Footnotes and Annotations ------------------------------- There are a number of requests to save text for later printing. "Footnotes" are printed at the bottom of the current page. "Delayed text" is very similar to a footnote except that it is printed when called for explicitly. This allows a list of references to appear (for example) at the end of each chapter, as is the convention in some disciplines. Most macro packages which supply this functionality also supply a means of automatically numbering either type of annotation. 3.2.7 Table of Contents ----------------------- "Tables of contents" are a type of delayed text having a tag (usually the page number) attached to each entry after a row of dots. The table accumulates throughout the paper until printed, usually after the paper has ended. Many macro packages provide the ability to have several tables of contents (e.g. a standard table of contents, a list of tables, etc). 3.2.8 Indices ------------- While some macro packages use the term "index", none actually provide that functionality. The facilities they call indices are actually more appropriate for tables of contents. To produce a real index in a document, external tools like the `makeindex' program are necessary. 3.2.9 Paper Formats ------------------- Some macro packages provide stock formats for various kinds of documents. Many of them provide a common format for the title and opening pages of a technical paper. The `mm' macros in particular provide formats for letters and memoranda. 3.2.10 Multiple Columns ----------------------- Some macro packages (but not `man') provide the ability to have two or more columns on a page. 3.2.11 Font and Size Changes ---------------------------- The built-in font and size functions are not always intuitive, so all macro packages provide macros to make these operations simpler. 3.2.12 Predefined Strings ------------------------- Most macro packages provide various predefined strings for a variety of uses; examples are sub- and superscripts, printable dates, quotes and various special characters. 3.2.13 Preprocessor Support --------------------------- All macro packages provide support for various preprocessors and may extend their functionality. For example, all macro packages mark tables (which are processed with `gtbl') by placing them between `TS' and `TE' macros. The `ms' macro package has an option, `.TS H', that prints a caption at the top of a new page (when the table is too long to fit on a single page). 3.2.14 Configuration and Customization -------------------------------------- Some macro packages provide means of customizing many of the details of how the package behaves. This ranges from setting the default type size to changing the appearance of section headers. 4 Macro Packages **************** This chapter documents the main macro packages that come with `groff'. Different main macro packages can't be used at the same time; for example groff -m man foo.man -m ms bar.doc doesn't work. Note that option arguments are processed before non-option arguments; the above (failing) sample is thus reordered to groff -m man -m ms foo.man bar.doc 4.1 `man' ========= This is the most popular and probably the most important macro package of `groff'. It is easy to use, and a vast majority of manual pages are based on it. 4.1.1 Options ------------- The command line format for using the `man' macros with `groff' is: groff -m man [ -rLL=LENGTH ] [ -rLT=LENGTH ] [ -rFT=DIST ] [ -rcR=1 ] [ -rC1 ] [ -rD1 ] [-rHY=FLAGS ] [ -rPNNN ] [ -rSXX ] [ -rXNNN ] [ -rIN=LENGTH ] [ -rSN=LENGTH ] [ FILES... ] It is possible to use `-man' instead of `-m man'. `-rcR=1' This option (the default if a TTY output device is used) creates a single, very long page instead of multiple pages. Use `-rcR=0' to disable it. `-rC1' If more than one manual page is given on the command line, number the pages continuously, rather than starting each at 1. `-rD1' Double-sided printing. Footers for even and odd pages are formatted differently. `-rFT=DIST' Set the position of the footer text to DIST. If positive, the distance is measured relative to the top of the page, otherwise it is relative to the bottom. The default is -0.5i. `-rHY=FLAGS' Set hyphenation flags. Possible values are 1 to hyphenate without restrictions, 2 to not hyphenate the last word on a page, 4 to not hyphenate the last two characters of a word, and 8 to not hyphenate the first two characters of a word. These values are additive; the default is 14. `-rIN=LENGTH' Set the body text indentation to LENGTH. If not specified, the indentation defaults to 7n (7 characters) in nroff mode and 7.2n otherwise. For nroff, this value should always be an integer multiple of unit `n' to get consistent indentation. `-rLL=LENGTH' Set line length to LENGTH. If not specified, the line length is set to respect any value set by a prior `ll' request (which _must_ be in effect when the `TH' macro is invoked), if this differs from the built-in default for the formatter; otherwise it defaults to 78n in nroff mode (this is 78 characters per line) and 6.5i in troff mode.(1) (*note Man options-Footnote-1::) `-rLT=LENGTH' Set title length to LENGTH. If not specified, the title length defaults to the line length. `-rPNNN' Page numbering starts with NNN rather than with 1. `-rSXX' Use XX (which can be 10, 11, or 12pt) as the base document font size instead of the default value of 10pt. `-rSN=LENGTH' Set the indentation for sub-subheadings to LENGTH. If not specified, the indentation defaults to 3n. `-rXNNN' After page NNN, number pages as NNNa, NNNb, NNNc, etc. For example, the option `-rX2' produces the following page numbers: 1, 2, 2a, 2b, 2c, etc. (1) Note that the use of a `.ll LENGTH' request to initialize the line length, prior to use of the `TH' macro, is supported for backward compatibility with some versions of the `man' program. _Always_ use the `-rLL=LENGTH' option, or an equivalent `.nr LL LENGTH' request, in preference to such a `.ll LENGTH' request. In particular, note that in nroff mode, the request `.ll 65n', (with any LENGTH expression which evaluates equal to 65n, i.e., the formatter's default line length in nroff mode), does _not_ set the line length to 65n (it is adjusted to the `man' macro package's default setting of 78n), whereas the use of the `-rLL=65n' option, or the `.nr LL 65n' request _does_ establish a line length of 65n. 4.1.2 Usage ----------- This section describes the available macros for manual pages. For further customization, put additional macros and requests into the file `man.local' which is loaded immediately after the `man' package. -- Macro: .TH title section [extra1 [extra2 [extra3]]] Set the title of the man page to TITLE and the section to SECTION, which must have a value between 1 and 8. The value of SECTION may also have a string appended, e.g. `.pm', to indicate a specific subsection of the man pages. Both TITLE and SECTION are positioned at the left and right in the header line (with SECTION in parentheses immediately appended to TITLE. EXTRA1 is positioned in the middle of the footer line. EXTRA2 is positioned at the left in the footer line (or at the left on even pages and at the right on odd pages if double-sided printing is active). EXTRA3 is centered in the header line. For HTML and XHTML output, headers and footers are completely suppressed. Additionally, this macro starts a new page; the new line number is 1 again (except if the `-rC1' option is given on the command line) - this feature is intended only for formatting multiple man pages; a single man page should contain exactly one `TH' macro at the beginning of the file. -- Macro: .SH [heading] Set up an unnumbered section heading sticking out to the left. Prints out all the text following `SH' up to the end of the line (or the text in the next line if there is no argument to `SH') in bold face (or the font specified by the string `HF'), one size larger than the base document size. Additionally, the left margin and the indentation for the following text is reset to its default value. -- Macro: .SS [heading] Set up an unnumbered (sub)section heading. Prints out all the text following `SS' up to the end of the line (or the text in the next line if there is no argument to `SS') in bold face (or the font specified by the string `HF'), at the same size as the base document size. Additionally, the left margin and the indentation for the following text is reset to its default value. -- Macro: .TP [nnn] Set up an indented paragraph with label. The indentation is set to NNN if that argument is supplied (the default unit is `n' if omitted), otherwise it is set to the previous indentation value specified with `TP', `IP', or `HP' (or to the default value if none of them have been used yet). The first line of text following this macro is interpreted as a string to be printed flush-left, as it is appropriate for a label. It is not interpreted as part of a paragraph, so there is no attempt to fill the first line with text from the following input lines. Nevertheless, if the label is not as wide as the indentation the paragraph starts at the same line (but indented), continuing on the following lines. If the label is wider than the indentation the descriptive part of the paragraph begins on the line following the label, entirely indented. Note that neither font shape nor font size of the label is set to a default value; on the other hand, the rest of the text has default font settings. -- Macro: .LP -- Macro: .PP -- Macro: .P These macros are mutual aliases. Any of them causes a line break at the current position, followed by a vertical space downwards by the amount specified by the `PD' macro. The font size and shape are reset to the default value (10pt roman if no `-rS' option is given on the command line). Finally, the current left margin and the indentation is restored. -- Macro: .IP [designator [nnn]] Set up an indented paragraph, using DESIGNATOR as a tag to mark its beginning. The indentation is set to NNN if that argument is supplied (default unit is `n'), otherwise it is set to the previous indentation value specified with `TP', `IP', or `HP' (or the default value if none of them have been used yet). Font size and face of the paragraph (but not the designator) are reset to their default values. To start an indented paragraph with a particular indentation but without a designator, use `""' (two double quotes) as the first argument of `IP'. For example, to start a paragraph with bullets as the designator and 4 en indentation, write .IP \(bu 4 -- Macro: .HP [nnn] Set up a paragraph with hanging left indentation. The indentation is set to NNN if that argument is supplied (default unit is `n'), otherwise it is set to the previous indentation value specified with `TP', `IP', or `HP' (or the default value if non of them have been used yet). Font size and face are reset to their default values. -- Macro: .RS [nnn] Move the left margin to the right by the value NNN if specified (default unit is `n'); otherwise it is set to the previous indentation value specified with `TP', `IP', or `HP' (or to the default value if none of them have been used yet). The indentation value is then set to the default. Calls to the `RS' macro can be nested. -- Macro: .RE [nnn] Move the left margin back to level NNN, restoring the previous left margin. If no argument is given, it moves one level back. The first level (i.e., no call to `RS' yet) has number 1, and each call to `RS' increases the level by 1. To summarize, the following macros cause a line break with the insertion of vertical space (which amount can be changed with the `PD' macro): `SH', `SS', `TP', `LP' (`PP', `P'), `IP', and `HP'. The macros `RS' and `RE' also cause a break but do not insert vertical space. Finally, the macros `SH', `SS', `LP' (`PP', `P'), and `RS' reset the indentation to its default value. 4.1.3 Macros to set fonts ------------------------- The standard font is roman; the default text size is 10 point. If command line option `-rS=N' is given, use Npt as the default text size. -- Macro: .SM [text] Set the text on the same line or the text on the next line in a font that is one point size smaller than the default font. -- Macro: .SB [text] Set the text on the same line or the text on the next line in bold face font, one point size smaller than the default font. -- Macro: .BI text Set its arguments alternately in bold face and italic, without a space between the arguments. Thus, .BI this "word and" that produces "thisword andthat" with "this" and "that" in bold face, and "word and" in italics. -- Macro: .IB text Set its arguments alternately in italic and bold face, without a space between the arguments. -- Macro: .RI text Set its arguments alternately in roman and italic, without a space between the arguments. -- Macro: .IR text Set its arguments alternately in italic and roman, without a space between the arguments. -- Macro: .BR text Set its arguments alternately in bold face and roman, without a space between the arguments. -- Macro: .RB text Set its arguments alternately in roman and bold face, without a space between the arguments. -- Macro: .B [text] Set TEXT in bold face. If no text is present on the line where the macro is called, then the text of the next line appears in bold face. -- Macro: .I [text] Set TEXT in italic. If no text is present on the line where the macro is called, then the text of the next line appears in italic. 4.1.4 Miscellaneous macros -------------------------- The default indentation is 7.2n in troff mode and 7n in nroff mode except for `grohtml' which ignores indentation. -- Macro: .DT Set tabs every 0.5 inches. Since this macro is always executed during a call to the `TH' macro, it makes sense to call it only if the tab positions have been changed. -- Macro: .PD [nnn] Adjust the empty space before a new paragraph (or section). The optional argument gives the amount of space (default unit is `v'); without parameter, the value is reset to its default value (1 line in nroff mode, 0.4v otherwise). This affects the macros `SH', `SS', `TP', `LP' (as well as `PP' and `P'), `IP', and `HP'. The following two macros are included for BSD compatibility. -- Macro: .AT [system [release]] Alter the footer for use with AT&T manpages. This command exists only for compatibility; don't use it. The first argument SYSTEM can be: `3' 7th Edition (the default) `4' System III `5' System V An optional second argument RELEASE to `AT' specifies the release number (such as "System V Release 3"). -- Macro: .UC [version] Alters the footer for use with BSD manpages. This command exists only for compatibility; don't use it. The argument can be: `3' 3rd Berkeley Distribution (the default) `4' 4th Berkeley Distribution `5' 4.2 Berkeley Distribution `6' 4.3 Berkeley Distribution `7' 4.4 Berkeley Distribution 4.1.5 Predefined strings ------------------------ The following strings are defined: -- String: \*[S] Switch back to the default font size. -- String: \*[HF] The typeface used for headings. The default is `B'. -- String: \*[R] The `registered' sign. -- String: \*[Tm] The `trademark' sign. -- String: \*[lq] -- String: \*[rq] Left and right quote. This is equal to `\(lq' and `\(rq', respectively. 4.1.6 Preprocessors in `man' pages ---------------------------------- If a preprocessor like `gtbl' or `geqn' is needed, it has become common usage to make the first line of the man page look like this: '\" WORD Note the single space character after the double quote. WORD consists of letters for the needed preprocessors: `e' for `geqn', `r' for `grefer', `t' for `gtbl'. Modern implementations of the `man' program read this first line and automatically call the right preprocessor(s). 4.1.7 Optional `man' extensions ------------------------------- Use the file `man.local' for local extensions to the `man' macros or for style changes. Custom headers and footers .......................... In groff versions 1.18.2 and later, you can specify custom headers and footers by redefining the following macros in `man.local'. -- Macro: .PT Control the content of the headers. Normally, the header prints the command name and section number on either side, and the optional fifth argument to `TH' in the center. -- Macro: .BT Control the content of the footers. Normally, the footer prints the page number and the third and fourth arguments to `TH'. Use the `FT' number register to specify the footer position. The default is -0.5i. Ultrix-specific man macros .......................... The `groff' source distribution includes a file named `man.ultrix', containing macros compatible with the Ultrix variant of `man'. Copy this file into `man.local' (or use the `mso' request to load it) to enable the following macros. -- Macro: .CT key Print `'. -- Macro: .CW Print subsequent text using the constant width (Courier) typeface. -- Macro: .Ds Begin a non-filled display. -- Macro: .De End a non-filled display started with `Ds'. -- Macro: .EX [indent] Begin a non-filled display using the constant width (Courier) typeface. Use the optional INDENT argument to indent the display. -- Macro: .EE End a non-filled display started with `EX'. -- Macro: .G [text] Set TEXT in Helvetica. If no text is present on the line where the macro is called, then the text of the next line appears in Helvetica. -- Macro: .GL [text] Set TEXT in Helvetica Oblique. If no text is present on the line where the macro is called, then the text of the next line appears in Helvetica Oblique. -- Macro: .HB [text] Set TEXT in Helvetica Bold. If no text is present on the line where the macro is called, then all text up to the next `HB' appears in Helvetica Bold. -- Macro: .TB [text] Identical to `HB'. -- Macro: .MS title sect [punct] Set a manpage reference in Ultrix format. The TITLE is in Courier instead of italic. Optional punctuation follows the section number without an intervening space. -- Macro: .NT [`C'] [title] Begin a note. Print the optional title, or the word "Note", centered on the page. Text following the macro makes up the body of the note, and is indented on both sides. If the first argument is `C', the body of the note is printed centered (the second argument replaces the word "Note" if specified). -- Macro: .NE End a note begun with `NT'. -- Macro: .PN path [punct] Set the path name in constant width (Courier), followed by optional punctuation. -- Macro: .Pn [punct] path [punct] If called with two arguments, identical to `PN'. If called with three arguments, set the second argument in constant width (Courier), bracketed by the first and third arguments in the current font. -- Macro: .R Switch to roman font and turn off any underlining in effect. -- Macro: .RN Print the string `'. -- Macro: .VS [`4'] Start printing a change bar in the margin if the number `4' is specified. Otherwise, this macro does nothing. -- Macro: .VE End printing the change bar begun by `VS'. Simple example .............. The following example `man.local' file alters the `SH' macro to add some extra vertical space before printing the heading. Headings are printed in Helvetica Bold. .\" Make the heading fonts Helvetica .ds HF HB . .\" Put more whitespace in front of headings. .rn SH SH-orig .de SH . if t .sp (u;\\n[PD]*2) . SH-orig \\$* .. 4.2 `mdoc' ========== See the `groff_mdoc(7)' man page (type `man groff_mdoc' at the command line). 4.3 `ms' ======== The `-ms' macros are suitable for reports, letters, books, user manuals, and so forth. The package provides macros for cover pages, section headings, paragraphs, lists, footnotes, pagination, and a table of contents. 4.3.1 Introduction to `ms' -------------------------- The original `-ms' macros were included with AT&T `troff' as well as the `man' macros. While the `man' package is intended for brief documents that can be read on-line as well as printed, the `ms' macros are suitable for longer documents that are meant to be printed rather than read on-line. The `ms' macro package included with `groff' is a complete, bottom-up re-implementation. Several macros (specific to AT&T or Berkeley) are not included, while several new commands are. *Note Differences from AT&T ms::, for more information. 4.3.2 General structure of an `ms' document ------------------------------------------- The `ms' macro package expects a certain amount of structure, but not as much as packages such as `man' or `mdoc'. The simplest documents can begin with a paragraph macro (such as `LP' or `PP'), and consist of text separated by paragraph macros or even blank lines. Longer documents have a structure as follows: *Document type* If you invoke the `RP' (report) macro on the first line of the document, `groff' prints the cover page information on its own page; otherwise it prints the information on the first page with your document text immediately following. Other document formats found in AT&T `troff' are specific to AT&T or Berkeley, and are not supported in `groff'. *Format and layout* By setting number registers, you can change your document's type (font and size), margins, spacing, headers and footers, and footnotes. *Note ms Document Control Registers::, for more details. *Cover page* A cover page consists of a title, the author's name and institution, an abstract, and the date.(1) (*note General ms Structure-Footnote-1::) *Note ms Cover Page Macros::, for more details. *Body* Following the cover page is your document. You can use the `ms' macros to write reports, letters, books, and so forth. The package is designed for structured documents, consisting of paragraphs interspersed with headings and augmented by lists, footnotes, tables, and other common constructs. *Note ms Body Text::, for more details. *Table of contents* Longer documents usually include a table of contents, which you can invoke by placing the `TC' macro at the end of your document. The `ms' macros have minimal indexing facilities, consisting of the `IX' macro, which prints an entry on standard error. Printing the table of contents at the end is necessary since `groff' is a single-pass text formatter, thus it cannot determine the page number of each section until that section has actually been set and printed. Since `ms' output is intended for hardcopy, you can manually relocate the pages containing the table of contents between the cover page and the body text after printing. (1) Actually, only the title is required. 4.3.3 Document control registers -------------------------------- The following is a list of document control number registers. For the sake of consistency, set registers related to margins at the beginning of your document, or just after the `RP' macro. You can set other registers later in your document, but you should keep them together at the beginning to make them easy to find and edit as necessary. Margin Settings ............... -- Register: \n[PO] Defines the page offset (i.e., the left margin). There is no explicit right margin setting; the combination of the `PO' and `LL' registers implicitly define the right margin width. Effective: next page. Default value: 1i. -- Register: \n[LL] Defines the line length (i.e., the width of the body text). Effective: next paragraph. Default: 6i. -- Register: \n[LT] Defines the title length (i.e., the header and footer width). This is usually the same as `LL', but not necessarily. Effective: next paragraph. Default: 6i. -- Register: \n[HM] Defines the header margin height at the top of the page. Effective: next page. Default: 1i. -- Register: \n[FM] Defines the footer margin height at the bottom of the page. Effective: next page. Default: 1i. Text Settings ............. -- Register: \n[PS] Defines the point size of the body text. If the value is larger than or equal to 1000, divide it by 1000 to get a fractional point size. For example, `.nr PS 10250' sets the document's point size to 10.25p. Effective: next paragraph. Default: 10p. -- Register: \n[VS] Defines the space between lines (line height plus leading). If the value is larger than or equal to 1000, divide it by 1000 to get a fractional point size. Due to backwards compatibility, `VS' must be smaller than 40000 (this is 40.0p). Effective: next paragraph. Default: 12p. -- Register: \n[PSINCR] Defines an increment in point size, which is applied to section headings at nesting levels below the value specified in `GROWPS'. The value of `PSINCR' should be specified in points, with the p scaling factor, and may include a fractional component; for example, `.nr PSINCR 1.5p' sets a point size increment of 1.5p. Effective: next section heading. Default: 1p. -- Register: \n[GROWPS] Defines the heading level below which the point size increment set by `PSINCR' becomes effective. Section headings at and above the level specified by `GROWPS' are printed at the point size set by `PS'; for each level below the value of `GROWPS', the point size is increased in steps equal to the value of `PSINCR'. Setting `GROWPS' to any value less than 2 disables the incremental heading size feature. Effective: next section heading. Default: 0. -- Register: \n[HY] Defines the hyphenation level. `HY' sets safely the value of the low-level `hy' register. Setting the value of `HY' to 0 is equivalent to using the `nh' request. Effective: next paragraph. Default: 14. -- Register: \n[FAM] Defines the font family used to typeset the document. Effective: next paragraph. Default: as defined in the output device. Paragraph Settings .................. -- Register: \n[PI] Defines the initial indentation of a (`PP' macro) paragraph. Effective: next paragraph. Default: 5n. -- Register: \n[PD] Defines the space between paragraphs. Effective: next paragraph. Default: 0.3v. -- Register: \n[QI] Defines the indentation on both sides of a quoted (`QP' macro) paragraph. Effective: next paragraph. Default: 5n. -- Register: \n[PORPHANS] Defines the minimum number of initial lines of any paragraph which should be kept together, to avoid orphan lines at the bottom of a page. If a new paragraph is started close to the bottom of a page, and there is insufficient space to accommodate `PORPHANS' lines before an automatic page break, then the page break is forced, before the start of the paragraph. Effective: next paragraph. Default: 1. -- Register: \n[HORPHANS] Defines the minimum number of lines of the following paragraph which should be kept together with any section heading introduced by the `NH' or `SH' macros. If a section heading is placed close to the bottom of a page, and there is insufficient space to accommodate both the heading and at least `HORPHANS' lines of the following paragraph, before an automatic page break, then the page break is forced before the heading. Effective: next paragraph. Default: 1. Footnote Settings ................. -- Register: \n[FL] Defines the length of a footnote. Effective: next footnote. Default: `\n[LL]' * 5 / 6. -- Register: \n[FI] Defines the footnote indentation. Effective: next footnote. Default: 2n. -- Register: \n[FF] The footnote format: `0' Print the footnote number as a superscript; indent the footnote (default). `1' Print the number followed by a period (like 1.) and indent the footnote. `2' Like 1, without an indentation. `3' Like 1, but print the footnote number as a hanging paragraph. Effective: next footnote. Default: 0. -- Register: \n[FPS] Defines the footnote point size. If the value is larger than or equal to 1000, divide it by 1000 to get a fractional point size. Effective: next footnote. Default: `\n[PS]' - 2. -- Register: \n[FVS] Defines the footnote vertical spacing. If the value is larger than or equal to 1000, divide it by 1000 to get a fractional point size. Effective: next footnote. Default: `\n[FPS]' + 2. -- Register: \n[FPD] Defines the footnote paragraph spacing. Effective: next footnote. Default: `\n[PD]' / 2. Miscellaneous Number Registers .............................. -- Register: \n[MINGW] Defines the minimum width between columns in a multi-column document. Effective: next page. Default: 2n. -- Register: \n[DD] Sets the vertical spacing before and after a display, a `tbl' table, an `eqn' equation, or a `pic' image. Effective: next paragraph. Default: 0.5v. 4.3.4 Cover page macros ----------------------- Use the following macros to create a cover page for your document in the order shown. -- Macro: .RP [`no'] Specifies the report format for your document. The report format creates a separate cover page. The default action (no `RP' macro) is to print a subset of the cover page on page 1 of your document. If you use the word `no' as an optional argument, `groff' prints a title page but does not repeat any of the title page information (title, author, abstract, etc.) on page 1 of the document. -- Macro: .P1 (P-one) Prints the header on page 1. The default is to suppress the header. -- Macro: .DA [...] (optional) Prints the current date, or the arguments to the macro if any, on the title page (if specified) and in the footers. This is the default for `nroff'. -- Macro: .ND [...] (optional) Prints the current date, or the arguments to the macro if any, on the title page (if specified) but not in the footers. This is the default for `troff'. -- Macro: .TL Specifies the document title. `groff' collects text following the `TL' macro into the title, until reaching the author name or abstract. -- Macro: .AU Specifies the author's name, which appears on the line (or lines) immediately following. You can specify multiple authors as follows: .AU John Doe .AI University of West Bumblefuzz .AU Martha Buck .AI Monolithic Corporation ... -- Macro: .AI Specifies the author's institution. You can specify multiple institutions in the same way that you specify multiple authors. -- Macro: .AB [`no'] Begins the abstract. The default is to print the word ABSTRACT, centered and in italics, above the text of the abstract. The word `no' as an optional argument suppresses this heading. -- Macro: .AE Ends the abstract. The following is example mark-up for a title page. .RP .TL The Inevitability of Code Bloat in Commercial and Free Software .AU J. Random Luser .AI University of West Bumblefuzz .AB This report examines the long-term growth of the code bases in two large, popular software packages; the free Emacs and the commercial Microsoft Word. While differences appear in the type or order of features added, due to the different methodologies used, the results are the same in the end. .PP The free software approach is shown to be superior in that while free software can become as bloated as commercial offerings, free software tends to have fewer serious bugs and the added features are in line with user demand. .AE ... the rest of the paper follows ... 4.3.5 Body text --------------- This section describes macros used to mark up the body of your document. Examples include paragraphs, sections, and other groups. 4.3.5.1 Paragraphs .................. The following paragraph types are available. -- Macro: .PP Sets a paragraph with an initial indentation. -- Macro: .LP Sets a paragraph without an initial indentation. -- Macro: .QP Sets a paragraph that is indented at both left and right margins. The effect is identical to the HTML `
' element. The next paragraph or heading returns margins to normal. -- Macro: .XP Sets a paragraph whose lines are indented, except for the first line. This is a Berkeley extension. The following markup uses all four paragraph macros. .NH 2 Cases used in the study .LP The following software and versions were considered for this report. .PP For commercial software, we chose .B "Microsoft Word for Windows" , starting with version 1.0 through the current version (Word 2000). .PP For free software, we chose .B Emacs , from its first appearance as a standalone editor through the current version (v20). See [Bloggs 2002] for details. .QP Franklin's Law applied to software: software expands to outgrow both RAM and disk space over time. .LP Bibliography: .XP Bloggs, Joseph R., .I "Everyone's a Critic" , Underground Press, March 2002. A definitive work that answers all questions and criticisms about the quality and usability of free software. The `PORPHANS' register (*note ms Document Control Registers::) operates in conjunction with each of these macros, to inhibit the printing of orphan lines at the bottom of any page. 4.3.5.2 Headings ................ Use headings to create a hierarchical structure for your document. The `ms' macros print headings in *bold*, using the same font family and point size as the body text. The following describes the heading macros: -- Macro: .NH curr-level -- Macro: .NH S level0 ... Numbered heading. The argument is either a numeric argument to indicate the level of the heading, or the letter `S' followed by numeric arguments to set the heading level explicitly. If you specify heading levels out of sequence, such as invoking `.NH 3' after `.NH 1', `groff' prints a warning on standard error. -- String: \*[SN] -- String: \*[SN-DOT] -- String: \*[SN-NO-DOT] After invocation of `NH', the assigned section number is made available in the strings `SN-DOT' (as it appears in a printed section heading with default formatting, followed by a terminating period), and `SN-NO-DOT' (with the terminating period omitted). The string `SN' is also defined, as an alias for `SN-DOT'; if preferred, you may redefine it as an alias for `SN-NO-DOT', by including the initialization .als SN SN-NO-DOT at any time *before* you would like the change to take effect. -- String: \*[SN-STYLE] You may control the style used to print section numbers, within numbered section headings, by defining an appropriate alias for the string `SN-STYLE'. The default style, in which the printed section number is followed by a terminating period, is obtained by defining the alias .als SN-STYLE SN-DOT If you prefer to omit the terminating period, from section numbers appearing in numbered section headings, you may define the alias .als SN-STYLE SN-NO-DOT Any such change in section numbering style becomes effective from the next use of `.NH', following redefinition of the alias for `SN-STYLE'. -- Macro: .SH [match-level] Unnumbered subheading. The optional MATCH-LEVEL argument is a GNU extension. It is a number indicating the level of the heading, in a manner analogous to the CURR-LEVEL argument to `.NH'. Its purpose is to match the point size, at which the heading is printed, to the size of a numbered heading at the same level, when the `GROWPS' and `PSINCR' heading size adjustment mechanism is in effect. *Note ms Document Control Registers::. The `HORPHANS' register (*note ms Document Control Registers::) operates in conjunction with the `NH' and `SH' macros, to inhibit the printing of orphaned section headings at the bottom of any page. 4.3.5.3 Highlighting .................... The `ms' macros provide a variety of methods to highlight or emphasize text: -- Macro: .B [txt [post [pre]]] Sets its first argument in *bold type*. If you specify a second argument, `groff' prints it in the previous font after the bold text, with no intervening space (this allows you to set punctuation after the highlighted text without highlighting the punctuation). Similarly, it prints the third argument (if any) in the previous font *before* the first argument. For example, .B foo ) ( prints (*foo*). If you give this macro no arguments, `groff' prints all text following in bold until the next highlighting, paragraph, or heading macro. -- Macro: .R [txt [post [pre]]] Sets its first argument in roman (or regular) type. It operates similarly to the `B' macro otherwise. -- Macro: .I [txt [post [pre]]] Sets its first argument in _italic type_. It operates similarly to the `B' macro otherwise. -- Macro: .CW [txt [post [pre]]] Sets its first argument in a `constant width face'. It operates similarly to the `B' macro otherwise. -- Macro: .BI [txt [post [pre]]] Sets its first argument in bold italic type. It operates similarly to the `B' macro otherwise. -- Macro: .BX [txt] Prints its argument and draws a box around it. If you want to box a string that contains spaces, use a digit-width space (`\0'). -- Macro: .UL [txt [post]] Prints its first argument with an underline. If you specify a second argument, `groff' prints it in the previous font after the underlined text, with no intervening space. -- Macro: .LG Prints all text following in larger type (two points larger than the current point size) until the next font size, highlighting, paragraph, or heading macro. You can specify this macro multiple times to enlarge the point size as needed. -- Macro: .SM Prints all text following in smaller type (two points smaller than the current point size) until the next type size, highlighting, paragraph, or heading macro. You can specify this macro multiple times to reduce the point size as needed. -- Macro: .NL Prints all text following in the normal point size (that is, the value of the `PS' register). -- String: \*[{] -- String: \*[}] Text enclosed with `\*{' and `\*}' is printed as a superscript. 4.3.5.4 Lists ............. The `IP' macro handles duties for all lists. -- Macro: .IP [marker [width]] The MARKER is usually a bullet glyph (`\[bu]') for unordered lists, a number (or auto-incrementing number register) for numbered lists, or a word or phrase for indented (glossary-style) lists. The WIDTH specifies the indentation for the body of each list item; its default unit is `n'. Once specified, the indentation remains the same for all list items in the document until specified again. The `PORPHANS' register (*note ms Document Control Registers::) operates in conjunction with the `IP' macro, to inhibit the printing of orphaned list markers at the bottom of any page. The following is an example of a bulleted list. A bulleted list: .IP \[bu] 2 lawyers .IP \[bu] guns .IP \[bu] money Produces: A bulleted list: o lawyers o guns o money The following is an example of a numbered list. .nr step 1 1 A numbered list: .IP \n[step] 3 lawyers .IP \n+[step] guns .IP \n+[step] money Produces: A numbered list: 1. lawyers 2. guns 3. money Note the use of the auto-incrementing number register in this example. The following is an example of a glossary-style list. A glossary-style list: .IP lawyers 0.4i Two or more attorneys. .IP guns Firearms, preferably large-caliber. .IP money Gotta pay for those lawyers and guns! Produces: A glossary-style list: lawyers Two or more attorneys. guns Firearms, preferably large-caliber. money Gotta pay for those lawyers and guns! In the last example, the `IP' macro places the definition on the same line as the term if it has enough space; otherwise, it breaks to the next line and starts the definition below the term. This may or may not be the effect you want, especially if some of the definitions break and some do not. The following examples show two possible ways to force a break. The first workaround uses the `br' request to force a break after printing the term or label. A glossary-style list: .IP lawyers 0.4i Two or more attorneys. .IP guns .br Firearms, preferably large-caliber. .IP money Gotta pay for those lawyers and guns! The second workaround uses the `\p' escape to force the break. Note the space following the escape; this is important. If you omit the space, `groff' prints the first word on the same line as the term or label (if it fits) *then* breaks the line. A glossary-style list: .IP lawyers 0.4i Two or more attorneys. .IP guns \p Firearms, preferably large-caliber. .IP money Gotta pay for those lawyers and guns! To set nested lists, use the `RS' and `RE' macros. *Note Indentation values in ms::, for more information. For example: .IP \[bu] 2 Lawyers: .RS .IP \[bu] Dewey, .IP \[bu] Cheatham, .IP \[bu] and Howe. .RE .IP \[bu] Guns Produces: o Lawyers: o Dewey, o Cheatham, o and Howe. o Guns 4.3.5.5 Indentation values .......................... In many situations, you may need to indentation a section of text while still wrapping and filling. *Note Lists in ms::, for an example of nested lists. -- Macro: .RS -- Macro: .RE These macros begin and end an indented section. The `PI' register controls the amount of indentation, allowing the indented text to line up under hanging and indented paragraphs. *Note ms Displays and Keeps::, for macros to indentation and turn off filling. 4.3.5.6 Tab Stops ................. Use the `ta' request to define tab stops as needed. *Note Tabs and Fields::. -- Macro: .TA Use this macro to reset the tab stops to the default for `ms' (every 5n). You can redefine the `TA' macro to create a different set of default tab stops. 4.3.5.7 Displays and keeps .......................... Use displays to show text-based examples or figures (such as code listings). Displays turn off filling, so lines of code are displayed as-is without inserting `br' requests in between each line. Displays can be "kept" on a single page, or allowed to break across pages. -- Macro: .DS L -- Macro: .LD -- Macro: .DE Left-justified display. The `.DS L' call generates a page break, if necessary, to keep the entire display on one page. The `LD' macro allows the display to break across pages. The `DE' macro ends the display. -- Macro: .DS I -- Macro: .ID -- Macro: .DE Indents the display as defined by the `DI' register. The `.DS I' call generates a page break, if necessary, to keep the entire display on one page. The `ID' macro allows the display to break across pages. The `DE' macro ends the display. -- Macro: .DS B -- Macro: .BD -- Macro: .DE Sets a block-centered display: the entire display is left-justified, but indented so that the longest line in the display is centered on the page. The `.DS B' call generates a page break, if necessary, to keep the entire display on one page. The `BD' macro allows the display to break across pages. The `DE' macro ends the display. -- Macro: .DS C -- Macro: .CD -- Macro: .DE Sets a centered display: each line in the display is centered. The `.DS C' call generates a page break, if necessary, to keep the entire display on one page. The `CD' macro allows the display to break across pages. The `DE' macro ends the display. -- Macro: .DS R -- Macro: .RD -- Macro: .DE Right-justifies each line in the display. The `.DS R' call generates a page break, if necessary, to keep the entire display on one page. The `RD' macro allows the display to break across pages. The `DE' macro ends the display. -- Macro: .Ds -- Macro: .De These two macros were formerly provided as aliases for `DS' and `DE', respectively. They have been removed, and should no longer be used. The original implementations of `DS' and `DE' are retained, and should be used instead. X11 documents which actually use `Ds' and `De' always load a specific macro file from the X11 distribution (`macros.t') which provides proper definitions for the two macros. On occasion, you may want to "keep" other text together on a page. For example, you may want to keep two paragraphs together, or a paragraph that refers to a table (or list, or other item) immediately following. The `ms' macros provide the `KS' and `KE' macros for this purpose. -- Macro: .KS -- Macro: .KE The `KS' macro begins a block of text to be kept on a single page, and the `KE' macro ends the block. -- Macro: .KF -- Macro: .KE Specifies a "floating keep"; if the keep cannot fit on the current page, `groff' holds the contents of the keep and allows text following the keep (in the source file) to fill in the remainder of the current page. When the page breaks, whether by an explicit `bp' request or by reaching the end of the page, `groff' prints the floating keep at the top of the new page. This is useful for printing large graphics or tables that do not need to appear exactly where specified. You can also use the `ne' request to force a page break if there is not enough vertical space remaining on the page. Use the following macros to draw a box around a section of text (such as a display). -- Macro: .B1 -- Macro: .B2 Marks the beginning and ending of text that is to have a box drawn around it. The `B1' macro begins the box; the `B2' macro ends it. Text in the box is automatically placed in a diversion (keep). 4.3.5.8 Tables, figures, equations, and references .................................................. The `ms' macros support the standard `groff' preprocessors: `tbl', `pic', `eqn', and `refer'. You mark text meant for preprocessors by enclosing it in pairs of tags as follows. -- Macro: .TS [`H'] -- Macro: .TE Denotes a table, to be processed by the `tbl' preprocessor. The optional argument `H' to `TS' instructs `groff' to create a running header with the information up to the `TH' macro. `groff' prints the header at the beginning of the table; if the table runs onto another page, `groff' prints the header on the next page as well. -- Macro: .PS -- Macro: .PE Denotes a graphic, to be processed by the `pic' preprocessor. You can create a `pic' file by hand, using the AT&T `pic' manual available on the Web as a reference, or by using a graphics program such as `xfig'. -- Macro: .EQ [align] -- Macro: .EN Denotes an equation, to be processed by the `eqn' preprocessor. The optional ALIGN argument can be `C', `L', or `I' to center (the default), left-justify, or indent the equation. -- Macro: .[ -- Macro: .] Denotes a reference, to be processed by the `refer' preprocessor. The GNU `refer(1)' man page provides a comprehensive reference to the preprocessor and the format of the bibliographic database. 4.3.5.9 An example multi-page table ................................... The following is an example of how to set up a table that may print across two or more pages. .TS H allbox expand; cb | cb . Text ...of heading... _ .TH .T& l | l . ... the rest of the table follows... .CW .TE 4.3.5.10 Footnotes .................. The `ms' macro package has a flexible footnote system. You can specify either numbered footnotes or symbolic footnotes (that is, using a marker such as a dagger symbol). -- String: \*[*] Specifies the location of a numbered footnote marker in the text. -- Macro: .FS -- Macro: .FE Specifies the text of the footnote. The default action is to create a numbered footnote; you can create a symbolic footnote by specifying a "mark" glyph (such as `\[dg]' for the dagger glyph) in the body text and as an argument to the `FS' macro, followed by the text of the footnote and the `FE' macro. You can control how `groff' prints footnote numbers by changing the value of the `FF' register. *Note ms Document Control Registers::. Footnotes can be safely used within keeps and displays, but you should avoid using numbered footnotes within floating keeps. You can set a second `\**' marker between a `\**' and its corresponding `.FS' entry; as long as each `FS' macro occurs _after_ the corresponding `\**' and the occurrences of `.FS' are in the same order as the corresponding occurrences of `\**'. 4.3.6 Page layout ----------------- The default output from the `ms' macros provides a minimalist page layout: it prints a single column, with the page number centered at the top of each page. It prints no footers. You can change the layout by setting the proper number registers and strings. 4.3.6.1 Headers and footers ........................... For documents that do not distinguish between odd and even pages, set the following strings: -- String: \*[LH] -- String: \*[CH] -- String: \*[RH] Sets the left, center, and right headers. -- String: \*[LF] -- String: \*[CF] -- String: \*[RF] Sets the left, center, and right footers. For documents that need different information printed in the even and odd pages, use the following macros: -- Macro: .OH 'left'center'right' -- Macro: .EH 'left'center'right' -- Macro: .OF 'left'center'right' -- Macro: .EF 'left'center'right' The `OH' and `EH' macros define headers for the odd and even pages; the `OF' and `EF' macros define footers for the odd and even pages. This is more flexible than defining the individual strings. You can replace the quote (`'') marks with any character not appearing in the header or footer text. To specify custom header and footer processing, redefine the following macros: -- Macro: .PT -- Macro: .HD -- Macro: .BT The `PT' macro defines a custom header; the `BT' macro defines a custom footer. These macros must handle odd/even/first page differences if necessary. The `HD' macro defines additional header processing to take place after executing the `PT' macro. 4.3.6.2 Margins ............... You control margins using a set of number registers. *Note ms Document Control Registers::, for details. 4.3.6.3 Multiple columns ........................ The `ms' macros can set text in as many columns as do reasonably fit on the page. The following macros are available; all of them force a page break if a multi-column mode is already set. However, if the current mode is single-column, starting a multi-column mode does _not_ force a page break. -- Macro: .1C Single-column mode. -- Macro: .2C Two-column mode. -- Macro: .MC [width [gutter]] Multi-column mode. If you specify no arguments, it is equivalent to the `2C' macro. Otherwise, WIDTH is the width of each column and GUTTER is the space between columns. The `MINGW' number register controls the default gutter width. 4.3.6.4 Creating a table of contents .................................... The facilities in the `ms' macro package for creating a table of contents are semi-automated at best. Assuming that you want the table of contents to consist of the document's headings, you need to repeat those headings wrapped in `XS' and `XE' macros. -- Macro: .XS [page] -- Macro: .XA [page] -- Macro: .XE These macros define a table of contents or an individual entry in the table of contents, depending on their use. The macros are very simple; they cannot indent a heading based on its level. The easiest way to work around this is to add tabs to the table of contents string. The following is an example: .NH 1 Introduction .XS Introduction .XE .LP ... .CW .NH 2 Methodology .XS Methodology .XE .LP ... You can manually create a table of contents by beginning with the `XS' macro for the first entry, specifying the page number for that entry as the argument to `XS'. Add subsequent entries using the `XA' macro, specifying the page number for that entry as the argument to `XA'. The following is an example: .XS 1 Introduction .XA 2 A Brief History of the Universe .XA 729 Details of Galactic Formation ... .XE -- Macro: .TC [`no'] Prints the table of contents on a new page, setting the page number to *i* (Roman lowercase numeral one). You should usually place this macro at the end of the file, since `groff' is a single-pass formatter and can only print what has been collected up to the point that the `TC' macro appears. The optional argument `no' suppresses printing the title specified by the string register `TOC'. -- Macro: .PX [`no'] Prints the table of contents on a new page, using the current page numbering sequence. Use this macro to print a manually-generated table of contents at the beginning of your document. The optional argument `no' suppresses printing the title specified by the string register `TOC'. The `Groff and Friends HOWTO' includes a `sed' script that automatically inserts `XS' and `XE' macro entries after each heading in a document. Altering the `NH' macro to automatically build the table of contents is perhaps initially more difficult, but would save a great deal of time in the long run if you use `ms' regularly. 4.3.6.5 Strings and Special Characters ...................................... The `ms' macros provide the following predefined strings. You can change the string definitions to help in creating documents in languages other than English. -- String: \*[REFERENCES] Contains the string printed at the beginning of the references (bibliography) page. The default is `References'. -- String: \*[ABSTRACT] Contains the string printed at the beginning of the abstract. The default is `ABSTRACT'. -- String: \*[TOC] Contains the string printed at the beginning of the table of contents. -- String: \*[MONTH1] -- String: \*[MONTH2] -- String: \*[MONTH3] -- String: \*[MONTH4] -- String: \*[MONTH5] -- String: \*[MONTH6] -- String: \*[MONTH7] -- String: \*[MONTH8] -- String: \*[MONTH9] -- String: \*[MONTH10] -- String: \*[MONTH11] -- String: \*[MONTH12] Prints the full name of the month in dates. The default is `January', `February', etc. The following special characters are available(1) (*note ms Strings and Special Characters-Footnote-1::): -- String: \*[-] Prints an em dash. -- String: \*[Q] -- String: \*[U] Prints typographer's quotes in troff, and plain quotes in nroff. `\*Q' is the left quote and `\*U' is the right quote. Improved accent marks are available in the `ms' macros. -- Macro: .AM Specify this macro at the beginning of your document to enable extended accent marks and special characters. This is a Berkeley extension. To use the accent marks, place them *after* the character being accented. Note that groff's native support for accents is superior to the following definitions. The following accent marks are available after invoking the `AM' macro: -- String: \*['] Acute accent. -- String: \*[`] Grave accent. -- String: \*[^] Circumflex. -- String: \*[,] Cedilla. -- String: \*[~] Tilde. -- String: \*[:] Umlaut. -- String: \*[v] Hacek. -- String: \*[_] Macron (overbar). -- String: \*[.] Underdot. -- String: \*[o] Ring above. The following are standalone characters available after invoking the `AM' macro: -- String: \*[?] Upside-down question mark. -- String: \*[!] Upside-down exclamation point. -- String: \*[8] German ß ligature. -- String: \*[3] Yogh. -- String: \*[Th] Uppercase thorn. -- String: \*[th] Lowercase thorn. -- String: \*[D-] Uppercase eth. -- String: \*[d-] Lowercase eth. -- String: \*[q] Hooked o. -- String: \*[ae] Lowercase æ ligature. -- String: \*[Ae] Uppercase Æ ligature. (1) For an explanation what special characters are see *note Special Characters::. 4.3.7 Differences from AT&T `ms' -------------------------------- This section lists the (minor) differences between the `groff -ms' macros and AT&T `troff -ms' macros. * The internals of `groff -ms' differ from the internals of AT&T `troff -ms'. Documents that depend upon implementation details of AT&T `troff -ms' may not format properly with `groff -ms'. * The general error-handling policy of `groff -ms' is to detect and report errors, rather than silently to ignore them. * `groff -ms' does not work in compatibility mode (this is, with the `-C' option). * There is no special support for typewriter-like devices. * `groff -ms' does not provide cut marks. * Multiple line spacing is not supported. Use a larger vertical spacing instead. * Some UNIX `ms' documentation says that the `CW' and `GW' number registers can be used to control the column width and gutter width, respectively. These number registers are not used in `groff -ms'. * Macros that cause a reset (paragraphs, headings, etc.) may change the indentation. Macros that change the indentation do not increment or decrement the indentation, but rather set it absolutely. This can cause problems for documents that define additional macros of their own. The solution is to use not the `in' request but instead the `RS' and `RE' macros. * To make `groff -ms' use the default page offset (which also specifies the left margin), the `PO' register must stay undefined until the first `-ms' macro is evaluated. This implies that `PO' should not be used early in the document, unless it is changed also: Remember that accessing an undefined register automatically defines it. -- Register: \n[GS] This number register is set to 1 by the `groff -ms' macros, but it is not used by the `AT&T' `troff -ms' macros. Documents that need to determine whether they are being formatted with `AT&T' `troff -ms' or `groff -ms' should use this number register. Emulations of a few ancient Bell Labs macros can be re-enabled by calling the otherwise undocumented `SC' section-header macro. Calling `SC' enables `UC' for marking up a product or application name, and the pair `P1'/`P2' for surrounding code example displays. These are not enabled by default because (a) they were not documented, in the original `ms' manual, and (b) the `P1' and `UC' macros collide with different macros with the same names in the Berkeley version of `ms'. These `groff' emulations are sufficient to give back the 1976 Kernighan & Cherry paper `Typsetting Mathematics - User's Guide' its section headings, and restore some text that had gone missing as arguments of undefined macros. No warranty express or implied is given as to how well the typographic details these produce match the original Bell Labs macros. 4.3.7.1 `troff' macros not appearing in `groff' ............................................... Macros missing from `groff -ms' are cover page macros specific to Bell Labs and Berkeley. The macros known to be missing are: `.TM' Technical memorandum; a cover sheet style `.IM' Internal memorandum; a cover sheet style `.MR' Memo for record; a cover sheet style `.MF' Memo for file; a cover sheet style `.EG' Engineer's notes; a cover sheet style `.TR' Computing Science Tech Report; a cover sheet style `.OK' Other keywords `.CS' Cover sheet information `.MH' A cover sheet macro 4.3.7.2 `groff' macros not appearing in AT&T `troff' .................................................... The `groff -ms' macros have a few minor extensions compared to the AT&T `troff -ms' macros. -- Macro: .AM Improved accent marks. *Note ms Strings and Special Characters::, for details. -- Macro: .DS I Indented display. The default behavior of AT&T `troff -ms' was to indent; the `groff' default prints displays flush left with the body text. -- Macro: .CW Print text in `constant width' (Courier) font. -- Macro: .IX Indexing term (printed on standard error). You can write a script to capture and process an index generated in this manner. The following additional number registers appear in `groff -ms': -- Register: \n[MINGW] Specifies a minimum space between columns (for multi-column output); this takes the place of the `GW' register that was documented but apparently not implemented in AT&T `troff'. Several new string registers are available as well. You can change these to handle (for example) the local language. *Note ms Strings and Special Characters::, for details. 4.3.8 Naming Conventions ------------------------ The following conventions are used for names of macros, strings and number registers. External names available to documents that use the `groff -ms' macros contain only uppercase letters and digits. Internally the macros are divided into modules; naming conventions are as follows: * Names used only within one module are of the form MODULE`*'NAME. * Names used outside the module in which they are defined are of the form MODULE`@'NAME. * Names associated with a particular environment are of the form ENVIRONMENT`:'NAME; these are used only within the `par' module. * NAME does not have a module prefix. * Constructed names used to implement arrays are of the form ARRAY`!'INDEX. Thus the groff ms macros reserve the following names: * Names containing the characters `*', `@', and `:'. * Names containing only uppercase letters and digits. 4.4 `me' ======== See the `meintro.me' and `meref.me' documents in groff's `doc' directory. 4.5 `mm' ======== See the `groff_mm(7)' man page (type `man groff_mm' at the command line). 4.6 `mom' ========= See the `groff_mom(7)' man page (type `man groff_mom' at the command line), which gives a short overview and a link to its extensive documentation in HTML format. 5 `gtroff' Reference ******************** This chapter covers *all* of the facilities of `gtroff'. Users of macro packages may skip it if not interested in details. 5.1 Text ======== `gtroff' input files contain text with control commands interspersed throughout. But, even without control codes, `gtroff' still does several things with the input text: * filling and adjusting * adding additional space after sentences * hyphenating * inserting implicit line breaks 5.1.1 Filling and Adjusting --------------------------- When `gtroff' reads text, it collects words from the input and fits as many of them together on one output line as it can. This is known as "filling". Once `gtroff' has a "filled" line, it tries to "adjust" it. This means it widens the spacing between words until the text reaches the right margin (in the default adjustment mode). Extra spaces between words are preserved, but spaces at the end of lines are ignored. Spaces at the front of a line cause a "break" (breaks are explained in *note Implicit Line Breaks::). *Note Manipulating Filling and Adjusting::. 5.1.2 Hyphenation ----------------- Since the odds are not great for finding a set of words, for every output line, which fit nicely on a line without inserting excessive amounts of space between words, `gtroff' hyphenates words so that it can justify lines without inserting too much space between words. It uses an internal hyphenation algorithm (a simplified version of the algorithm used within TeX) to indicate which words can be hyphenated and how to do so. When a word is hyphenated, the first part of the word is added to the current filled line being output (with an attached hyphen), and the other portion is added to the next line to be filled. *Note Manipulating Hyphenation::. 5.1.3 Sentences --------------- Although it is often debated, some typesetting rules say there should be different amounts of space after various punctuation marks. For example, the `Chicago typsetting manual' says that a period at the end of a sentence should have twice as much space following it as would a comma or a period as part of an abbreviation. `gtroff' does this by flagging certain characters (normally `!', `?', and `.') as "end-of-sentence" characters. When `gtroff' encounters one of these characters at the end of a line, it appends a normal space followed by a "sentence space" in the formatted output. (This justifies one of the conventions mentioned in *note Input Conventions::.) In addition, the following characters and symbols are treated transparently while handling end-of-sentence characters: `"', `'', `)', `]', `*', `\[dg]', and `\[rq]'. See the `cflags' request in *note Using Symbols::, for more details. To prevent the insertion of extra space after an end-of-sentence character (at the end of a line), append `\&'. 5.1.4 Tab Stops --------------- `gtroff' translates "tabulator characters", also called "tabs" (normally code point ASCII `0x09' or EBCDIC `0x05'), in the input into movements to the next tabulator stop. These tab stops are initially located every half inch across the page. Using this, simple tables can be made easily. However, it can often be deceptive as the appearance (and width) of the text on a terminal and the results from `gtroff' can vary greatly. Also, a possible sticking point is that lines beginning with tab characters are still filled, again producing unexpected results. For example, the following input 1 2 3 4 5 produces 1 2 3 4 5 *Note Tabs and Fields::. 5.1.5 Implicit Line Breaks -------------------------- An important concept in `gtroff' is the "break". When a break occurs, `gtroff' outputs the partially filled line (unjustified), and resumes collecting and filling text on the next output line. There are several ways to cause a break in `gtroff'. A blank line not only causes a break, but it also outputs a one-line vertical space (effectively a blank line). Note that this behaviour can be modified with the blank line macro request `blm'. *Note Blank Line Traps::. A line that begins with a space causes a break and the space is output at the beginning of the next line. Note that this space isn't adjusted, even in fill mode; however, the behaviour can be modified with the leading spaces macro request `lsm'. *Note Leading Spaces Traps::. The end of file also causes a break - otherwise the last line of the document may vanish! Certain requests also cause breaks, implicitly or explicitly. This is discussed in *note Manipulating Filling and Adjusting::. 5.1.6 Input Conventions ----------------------- Since `gtroff' does filling automatically, it is traditional in `groff' not to try and type things in as nicely formatted paragraphs. These are some conventions commonly used when typing `gtroff' text: * Break lines after punctuation, particularly at the end of a sentence and in other logical places. Keep separate phrases on lines by themselves, as entire phrases are often added or deleted when editing. * Try to keep lines less than 40-60 characters, to allow space for inserting more text. * Do not try to do any formatting in a WYSIWYG manner (i.e., don't try using spaces to get proper indentation). 5.1.7 Input Encodings --------------------- Currently, the following input encodings are available. cp1047 This input encoding works only on EBCDIC platforms (and vice versa, the other input encodings don't work with EBCDIC); the file `cp1047.tmac' is by default loaded at start-up. latin-1 This is the default input encoding on non-EBCDIC platforms; the file `latin1.tmac' is loaded at start-up. latin-2 To use this encoding, either say `.mso latin2.tmac' at the very beginning of your document or use `-mlatin2' as a command line argument for `groff'. latin-5 For Turkish. Either say `.mso latin9.tmac' at the very beginning of your document or use `-mlatin9' as a command line argument for `groff'. latin-9 (latin-0) This encoding is intended (at least in Europe) to replace latin-1 encoding. The main difference to latin-1 is that latin-9 contains the Euro character. To use this encoding, either say `.mso latin9.tmac' at the very beginning of your document or use `-mlatin9' as a command line argument for `groff'. Note that it can happen that some input encoding characters are not available for a particular output device. For example, saying groff -Tlatin1 -mlatin9 ... fails if you use the Euro character in the input. Usually, this limitation is present only for devices which have a limited set of output glyphs (e.g. `-Tascii' and `-Tlatin1'); for other devices it is usually sufficient to install proper fonts which contain the necessary glyphs. Due to the importance of the Euro glyph in Europe, the groff package now comes with a POSTSCRIPT font called `freeeuro.pfa' which provides various glyph shapes for the Euro. In other words, latin-9 encoding is supported for the `-Tps' device out of the box (latin-2 isn't). By its very nature, `-Tutf8' supports all input encodings; `-Tdvi' has support for both latin-2 and latin-9 if the command line `-mec' is used also to load the file `ec.tmac' (which flips to the EC fonts). 5.2 Measurements ================ `gtroff' (like many other programs) requires numeric parameters to specify various measurements. Most numeric parameters(1) (*note Measurements-Footnote-1::) may have a "measurement unit" attached. These units are specified as a single character which immediately follows the number or expression. Each of these units are understood, by `gtroff', to be a multiple of its "basic unit". So, whenever a different measurement unit is specified `gtroff' converts this into its "basic units". This basic unit, represented by a `u', is a device dependent measurement which is quite small, ranging from 1/75th to 1/72000th of an inch. The values may be given as fractional numbers; however, fractional basic units are always rounded to integers. Some of the measurement units are completely independent of any of the current settings (e.g. type size) of `gtroff'. `i' Inches. An antiquated measurement unit still in use in certain backwards countries with incredibly low-cost computer equipment. One inch is equal to 2.54cm. `c' Centimeters. One centimeter is equal to 0.3937in. `p' Points. This is a typesetter's measurement used for measure type size. It is 72 points to an inch. `P' Pica. Another typesetting measurement. 6 Picas to an inch (and 12 points to a pica). `s' `z' *Note Fractional Type Sizes::, for a discussion of these units. `f' Fractions. Value is 65536. *Note Colors::, for usage. The other measurements understood by `gtroff' depend on settings currently in effect in `gtroff'. These are very useful for specifying measurements which should look proper with any size of text. `m' Ems. This unit is equal to the current font size in points. So called because it is _approximately_ the width of the letter `m' in the current font. `n' Ens. In `groff', this is half of an em. `v' Vertical space. This is equivalent to the current line spacing. *Note Sizes::, for more information about this. `M' 100ths of an em. (1) those that specify vertical or horizontal motion or a type size 5.2.1 Default Units ------------------- Many requests take a default unit. While this can be helpful at times, it can cause strange errors in some expressions. For example, the line length request expects em units. Here are several attempts to get a line length of 3.5 inches and their results: 3.5i => 3.5i 7/2 => 0i 7/2i => 0i (7 / 2)u => 0i 7i/2 => 0.1i 7i/2u => 3.5i Everything is converted to basic units first. In the above example it is assumed that 1i equals 240u, and 1m equals 10p (thus 1m equals 33u). The value 7i/2 is first handled as 7i/2m, then converted to 1680u/66u which is 25u, and this is approximately 0.1i. As can be seen, a scaling indicator after a closing parenthesis is simply ignored. Thus, the safest way to specify measurements is to always attach a scaling indicator. If you want to multiply or divide by a certain scalar value, use `u' as the unit for that value. 5.3 Expressions =============== `gtroff' has most arithmetic operators common to other languages: * Arithmetic: `+' (addition), `-' (subtraction), `/' (division), `*' (multiplication), `%' (modulo). `gtroff' only provides integer arithmetic. The internal type used for computing results is `int', which is usually a 32bit signed integer. * Comparison: `<' (less than), `>' (greater than), `<=' (less than or equal), `>=' (greater than or equal), `=' (equal), `==' (the same as `='). * Logical: `&' (logical and), `:' (logical or). * Unary operators: `-' (negating, i.e. changing the sign), `+' (just for completeness; does nothing in expressions), `!' (logical not; this works only within `if' and `while' requests).(1) (*note Expressions-Footnote-1::) See below for the use of unary operators in motion requests. The logical not operator, as described above, works only within `if' and `while' requests. Furthermore, it may appear only at the beginning of an expression, and negates the entire expression. Attempting to insert the `!' operator within the expression results in a `numeric expression expected' warning. This maintains compatibility with old versions of `troff'. Example: .nr X 1 .nr Y 0 .\" This does not work as expected .if (\n[X])&(!\n[Y]) .nop X only . .\" Use this construct instead .if (\n[X]=1)&(\n[Y]=0) .nop X only * Extrema: `>?' (maximum), `? \n[y]) The register `z' now contains 5. * Scaling: `(C;E)'. Evaluate E using C as the default scaling indicator. If C is missing, ignore scaling indicators in the evaluation of E. Parentheses may be used as in any other language. However, in `gtroff' they are necessary to ensure order of evaluation. `gtroff' has no operator precedence; expressions are evaluated left to right. This means that `gtroff' evaluates `3+5*4' as if it were parenthesized like `(3+5)*4', not as `3+(5*4)', as might be expected. For many requests which cause a motion on the page, the unary operators `+' and `-' work differently if leading an expression. They then indicate a motion relative to the current position (down or up, respectively). Similarly, a leading `|' operator indicates an absolute position. For vertical movements, it specifies the distance from the top of the page; for horizontal movements, it gives the distance from the beginning of the _input_ line. `+' and `-' are also treated differently by the following requests and escapes: `bp', `in', `ll', `lt', `nm', `nr', `pl', `pn', `po', `ps', `pvs', `rt', `ti', `\H', `\R', and `\s'. Here, leading plus and minus signs indicate increments and decrements. *Note Setting Registers::, for some examples. -- Escape: \B'anything' Return 1 if ANYTHING is a valid numeric expression; or 0 if ANYTHING is empty or not a valid numeric expression. Due to the way arguments are parsed, spaces are not allowed in expressions, unless the entire expression is surrounded by parentheses. *Note Request and Macro Arguments::, and *note Conditionals and Loops::. (1) Note that, for example, `!(-1)' evaluates to `true' because `gtroff' treats both negative numbers and zero as `false'. 5.4 Identifiers =============== Like any other language, `gtroff' has rules for properly formed "identifiers". In `gtroff', an identifier can be made up of almost any printable character, with the exception of the following characters: * Whitespace characters (spaces, tabs, and newlines). * Backspace (ASCII `0x08' or EBCDIC `0x16') and character code `0x01'. * The following input characters are invalid and are ignored if `groff' runs on a machine based on ASCII, causing a warning message of type `input' (see *note Debugging::, for more details): `0x00', `0x0B', `0x0D'-`0x1F', `0x80'-`0x9F'. And here are the invalid input characters if `groff' runs on an EBCDIC host: `0x00', `0x08', `0x09', `0x0B', `0x0D'-`0x14', `0x17'-`0x1F', `0x30'-`0x3F'. Currently, some of these reserved codepoints are used internally, thus making it non-trivial to extend `gtroff' to cover Unicode or other character sets and encodings which use characters of these ranges. Note that invalid characters are removed before parsing; an identifier `foo', followed by an invalid character, followed by `bar' is treated as `foobar'. For example, any of the following is valid. br PP (l end-list @_ Note that identifiers longer than two characters with a closing bracket (`]') in its name can't be accessed with escape sequences which expect an identifier as a parameter. For example, `\[foo]]' accesses the glyph `foo', followed by `]', whereas `\C'foo]'' really asks for glyph `foo]'. To avoid problems with the `refer' preprocessor, macro names should not start with `[' or `]'. Due to backwards compatibility, everything after `.[' and `.]' is handled as a special argument to `refer'. For example, `.[foo' makes `refer' to start a reference, using `foo' as a parameter. -- Escape: \A'ident' Test whether an identifier IDENT is valid in `gtroff'. It expands to the character 1 or 0 according to whether its argument (usually delimited by quotes) is or is not acceptable as the name of a string, macro, diversion, number register, environment, or font. It returns 0 if no argument is given. This is useful for looking up user input in some sort of associative table. \A'end-list' => 1 *Note Escapes::, for details on parameter delimiting characters. Identifiers in `gtroff' can be any length, but, in some contexts, `gtroff' needs to be told where identifiers end and text begins (and in different ways depending on their length): * Single character. * Two characters. Must be prefixed with `(' in some situations. * Arbitrary length (`gtroff' only). Must be bracketed with `[' and `]' in some situations. Any length identifier can be put in brackets. Unlike many other programming languages, undefined identifiers are silently ignored or expanded to nothing. When `gtroff' finds an undefined identifier, it emits a warning, doing the following: * If the identifier is a string, macro, or diversion, `gtroff' defines it as empty. * If the identifier is a number register, `gtroff' defines it with a value of 0. *Note Warnings::., *note Interpolating Registers::, and *note Strings::. Note that macros, strings, and diversions share the same name space. .de xxx . nop foo .. . .di xxx bar .br .di . .xxx => bar As can be seen in the previous example, `gtroff' reuses the identifier `xxx', changing it from a macro to a diversion. No warning is emitted! The contents of the first macro definition is lost. *Note Interpolating Registers::, and *note Strings::. 5.5 Embedded Commands ===================== Most documents need more functionality beyond filling, adjusting and implicit line breaking. In order to gain further functionality, `gtroff' allows commands to be embedded into the text, in two ways. The first is a "request" which takes up an entire line, and does some large-scale operation (e.g. break lines, start new pages). The other is an "escape" which can be usually embedded anywhere in the text; most requests can accept it even as an argument. Escapes generally do more minor operations like sub- and superscripts, print a symbol, etc. 5.5.1 Requests -------------- A request line begins with a control character, which is either a single quote (`'', the "no-break control character") or a period (`.', the normal "control character"). These can be changed; see *note Character Translations::, for details. After this there may be optional tabs or spaces followed by an identifier which is the name of the request. This may be followed by any number of space-separated arguments (_no_ tabs here). Since a control character followed by whitespace only is ignored, it is common practice to use this feature for structuring the source code of documents or macro packages. .de foo . tm This is foo. .. . . .de bar . tm This is bar. .. Another possibility is to use the blank line macro request `blm' by assigning an empty macro to it. .de do-nothing .. .blm do-nothing \" activate blank line macro .de foo . tm This is foo. .. .de bar . tm This is bar. .. .blm \" deactivate blank line macro *Note Blank Line Traps::. To begin a line with a control character without it being interpreted, precede it with `\&'. This represents a zero width space, which means it does not affect the output. In most cases the period is used as a control character. Several requests cause a break implicitly; using the single quote control character prevents this. -- Register: \n[.br] A read-only number register which is set to 1 if a macro is called with the normal control character (as defined with the `cc' request), and set to 0 otherwise. This allows to reliably modify requests. .als bp*orig bp .de bp . tm before bp . ie \\n[.br] .bp*orig . el 'bp*orig . tm after bp .. Using this register outside of a macro makes no sense (it always returns zero in such cases). If a macro is called as a string (this is, using `\*'), the value of the `.br' register is inherited from the calling macro. 5.5.1.1 Request and Macro Arguments ................................... Arguments to requests and macros are processed much like the shell: The line is split into arguments according to spaces.(1) (*note Request and Macro Arguments-Footnote-1::) An argument to a macro which is intended to contain spaces can either be enclosed in double quotes, or have the spaces "escaped" with backslashes. This is _not_ true for requests. Here are a few examples for a hypothetical macro `uh': .uh The Mouse Problem .uh "The Mouse Problem" .uh The\ Mouse\ Problem The first line is the `uh' macro being called with 3 arguments, `The', `Mouse', and `Problem'. The latter two have the same effect of calling the `uh' macro with one argument, `The Mouse Problem'.(2) (*note Request and Macro Arguments-Footnote-2::) A double quote which isn't preceded by a space doesn't start a macro argument. If not closing a string, it is printed literally. For example, .xxx a" "b c" "de"fg" has the arguments `a"', `b c', `de', and `fg"'. Don't rely on this obscure behaviour! There are two possibilities to get a double quote reliably. * Enclose the whole argument with double quotes and use two consecutive double quotes to represent a single one. This traditional solution has the disadvantage that double quotes don't survive argument expansion again if called in compatibility mode (using the `-C' option of `groff'): .de xx . tm xx: `\\$1' `\\$2' `\\$3' . . yy "\\$1" "\\$2" "\\$3" .. .de yy . tm yy: `\\$1' `\\$2' `\\$3' .. .xx A "test with ""quotes""" . => xx: `A' `test with "quotes"' `.' => yy: `A' `test with ' `quotes""' If not in compatibility mode, you get the expected result xx: `A' `test with "quotes"' `.' yy: `A' `test with "quotes"' `.' since `gtroff' preserves the input level. * Use the double quote glyph `\(dq'. This works with and without compatibility mode enabled since `gtroff' doesn't convert `\(dq' back to a double quote input character. Note that this method won't work with UNIX `troff' in general since the glyph `dq' isn't defined normally. Double quotes in the `ds' request are handled differently. *Note Strings::, for more details. (1) Plan 9's `troff' implementation also allows tabs for argument separation - `gtroff' intentionally doesn't support this. (2) The last solution, i.e., using escaped spaces, is "classical" in the sense that it can be found in most `troff' documents. Nevertheless, it is not optimal in all situations, since `\ ' inserts a fixed-width, non-breaking space character which can't stretch. `gtroff' provides a different command `\~' to insert a stretchable, non-breaking space. 5.5.2 Macros ------------ `gtroff' has a "macro" facility for defining a series of lines which can be invoked by name. They are called in the same manner as requests - arguments also may be passed basically in the same manner. *Note Writing Macros::, and *note Request and Macro Arguments::. 5.5.3 Escapes ------------- Escapes may occur anywhere in the input to `gtroff'. They usually begin with a backslash and are followed by a single character which indicates the function to be performed. The escape character can be changed; see *note Character Translations::. Escape sequences which require an identifier as a parameter accept three possible syntax forms. * The next single character is the identifier. * If this single character is an opening parenthesis, take the following two characters as the identifier. Note that there is no closing parenthesis after the identifier. * If this single character is an opening bracket, take all characters until a closing bracket as the identifier. Examples: \fB \n(XX \*[TeX] Other escapes may require several arguments and/or some special format. In such cases the argument is traditionally enclosed in single quotes (and quotes are always used in this manual for the definitions of escape sequences). The enclosed text is then processed according to what that escape expects. Example: \l'1.5i\(bu' Note that the quote character can be replaced with any other character which does not occur in the argument (even a newline or a space character) in the following escapes: `\o', `\b', and `\X'. This makes e.g. A caf \o e\' in Paris => A café in Paris possible, but it is better not to use this feature to avoid confusion. The following escapes sequences (which are handled similarly to characters since they don't take a parameter) are also allowed as delimiters: `\%', `\ ', `\|', `\^', `\{', `\}', `\'', `\`', `\-', `\_', `\!', `\?', `\)', `\/', `\,', `\&', `\:', `\~', `\0', `\a', `\c', `\d', `\e', `\E', `\p', `\r', `\t', and `\u'. Again, don't use these if possible. No newline characters as delimiters are allowed in the following escapes: `\A', `\B', `\Z', `\C', and `\w'. Finally, the escapes `\D', `\h', `\H', `\l', `\L', `\N', `\R', `\s', `\S', `\v', and `\x' can't use the following characters as delimiters: * The digits `0'-`9'. * The (single-character) operators `+-/*%<>=&:().'. * The space, tab, and newline characters. * All escape sequences except `\%', `\:', `\{', `\}', `\'', `\`', `\-', `\_', `\!', `\/', `\c', `\e', and `\p'. To have a backslash (actually, the current escape character) appear in the output several escapes are defined: `\\', `\e' or `\E'. These are very similar, and only differ with respect to being used in macros or diversions. *Note Character Translations::, for an exact description of those escapes. *Note Implementation Differences::, *note Copy-in Mode::, and *note Diversions::, *note Identifiers::, for more information. 5.5.3.1 Comments ................ Probably one of the most(1) (*note Comments-Footnote-1::) common forms of escapes is the comment. -- Escape: \" Start a comment. Everything to the end of the input line is ignored. This may sound simple, but it can be tricky to keep the comments from interfering with the appearance of the final output. If the escape is to the right of some text or a request, that portion of the line is ignored, but the space leading up to it is noticed by `gtroff'. This only affects the `ds' and `as' request and its variants. One possibly irritating idiosyncracy is that tabs must not be used to line up comments. Tabs are not treated as whitespace between the request and macro arguments. A comment on a line by itself is treated as a blank line, because after eliminating the comment, that is all that remains: Test \" comment Test produces Test Test To avoid this, it is common to start the line with `.\"' which causes the line to be treated as an undefined request and thus ignored completely. Another commenting scheme seen sometimes is three consecutive single quotes (`'''') at the beginning of a line. This works, but `gtroff' gives a warning about an undefined macro (namely `'''), which is harmless, but irritating. -- Escape: \# To avoid all this, `gtroff' has a new comment mechanism using the `\#' escape. This escape works the same as `\"' except that the newline is also ignored: Test \# comment Test produces Test Test as expected. -- Request: .ig [end] Ignore all input until `gtroff' encounters the macro named `.'END on a line by itself (or `..' if END is not specified). This is useful for commenting out large blocks of text: text text text... .ig This is part of a large block of text that has been temporarily(?) commented out. We can restore it simply by removing the .ig request and the ".." at the end of the block. .. More text text text... produces text text text... More text text text... Note that the commented-out block of text does not cause a break. The input is read in copy-mode; auto-incremented registers _are_ affected (*note Auto-increment::). (1) Unfortunately, this is a lie. But hopefully future `gtroff' hackers will believe it `:-)' 5.6 Registers ============= Numeric variables in `gtroff' are called "registers". There are a number of built-in registers, supplying anything from the date to details of formatting parameters. *Note Identifiers::, for details on register identifiers. 5.6.1 Setting Registers ----------------------- Define or set registers using the `nr' request or the `\R' escape. Although the following requests and escapes can be used to create registers, simply using an undefined register will cause it to be set to zero. -- Request: .nr ident value -- Escape: \R'ident value' Set number register IDENT to VALUE. If IDENT doesn't exist, `gtroff' creates it. The argument to `\R' usually has to be enclosed in quotes. *Note Escapes::, for details on parameter delimiting characters. The `\R' escape doesn't produce an input token in `gtroff'; in other words, it vanishes completely after `gtroff' has processed it. For example, the following two lines are equivalent: .nr a (((17 + (3 * 4))) % 4) \R'a (((17 + (3 * 4))) % 4)' => 1 Note that the complete transparency of `\R' can cause surprising effects if you use number registers like `.k' which get evaluated at the time they are accessed. .ll 1.6i . aaa bbb ccc ddd eee fff ggg hhh\R':k \n[.k]' .tm :k == \n[:k] => :k == 126950 . .br . aaa bbb ccc ddd eee fff ggg hhh\h'0'\R':k \n[.k]' .tm :k == \n[:k] => :k == 15000 If you process this with the POSTSCRIPT device (`-Tps'), there will be a line break eventually after `ggg' in both input lines. However, after processing the space after `ggg', the partially collected line is not overfull yet, so `troff' continues to collect input until it sees the space (or in this case, the newline) after `hhh'. At this point, the line is longer than the line length, and the line gets broken. In the first input line, since the `\R' escape leaves no traces, the check for the overfull line hasn't been done yet at the point where `\R' gets handled, and you get a value for the `.k' number register which is even greater than the current line length. In the second input line, the insertion of `\h'0'' to emit an invisible zero-width space forces `troff' to check the line length which in turn causes the start of a new output line. Now `.k' returns the expected value. Both `nr' and `\R' have two additional special forms to increment or decrement a register. -- Request: .nr ident +value -- Request: .nr ident -value -- Escape: \R'ident +value' -- Escape: \R'ident -value' Increment (decrement) register IDENT by VALUE. .nr a 1 .nr a +1 \na => 2 To assign the negated value of a register to another register, some care must be taken to get the desired result: .nr a 7 .nr b 3 .nr a -\nb \na => 4 .nr a (-\nb) \na => -3 The surrounding parentheses prevent the interpretation of the minus sign as a decrementing operator. An alternative is to start the assignment with a `0': .nr a 7 .nr b -3 .nr a \nb \na => 4 .nr a 0\nb \na => -3 -- Request: .rr ident Remove number register IDENT. If IDENT doesn't exist, the request is ignored. -- Request: .rnn ident1 ident2 Rename number register IDENT1 to IDENT2. If either IDENT1 or IDENT2 doesn't exist, the request is ignored. -- Request: .aln ident1 ident2 Create an alias IDENT1 for a number register IDENT2. The new name and the old name are exactly equivalent. If IDENT1 is undefined, a warning of type `reg' is generated, and the request is ignored. *Note Debugging::, for information about warnings. 5.6.2 Interpolating Registers ----------------------------- Numeric registers can be accessed via the `\n' escape. -- Escape: \ni -- Escape: \n(id -- Escape: \n[ident] Interpolate number register with name IDENT (one-character name I, two-character name ID). This means that the value of the register is expanded in-place while `gtroff' is parsing the input line. Nested assignments (also called indirect assignments) are possible. .nr a 5 .nr as \na+\na \n(as => 10 .nr a1 5 .nr ab 6 .ds str b .ds num 1 \n[a\n[num]] => 5 \n[a\*[str]] => 6 5.6.3 Auto-increment -------------------- Number registers can also be auto-incremented and auto-decremented. The increment or decrement value can be specified with a third argument to the `nr' request or `\R' escape. -- Request: .nr ident value incr Set number register IDENT to VALUE; the increment for auto-incrementing is set to INCR. Note that the `\R' escape doesn't support this notation. To activate auto-incrementing, the escape `\n' has a special syntax form. -- Escape: \n+i -- Escape: \n-i -- Escape: \n(+id -- Escape: \n(-id -- Escape: \n+(id -- Escape: \n-(id -- Escape: \n[+ident] -- Escape: \n[-ident] -- Escape: \n+[ident] -- Escape: \n-[ident] Before interpolating, increment or decrement IDENT (one-character name I, two-character name ID) by the auto-increment value as specified with the `nr' request (or the `\R' escape). If no auto-increment value has been specified, these syntax forms are identical to `\n'. For example, .nr a 0 1 .nr xx 0 5 .nr foo 0 -2 \n+a, \n+a, \n+a, \n+a, \n+a .br \n-(xx, \n-(xx, \n-(xx, \n-(xx, \n-(xx .br \n+[foo], \n+[foo], \n+[foo], \n+[foo], \n+[foo] produces 1, 2, 3, 4, 5 -5, -10, -15, -20, -25 -2, -4, -6, -8, -10 To change the increment value without changing the value of a register (A in the example), the following can be used: .nr a \na 10 5.6.4 Assigning Formats ----------------------- When a register is used, it is always textually replaced (or interpolated) with a representation of that number. This output format can be changed to a variety of formats (numbers, Roman numerals, etc.). This is done using the `af' request. -- Request: .af ident format Change the output format of a number register. The first argument IDENT is the name of the number register to be changed, and the second argument FORMAT is the output format. The following output formats are available: `1' Decimal arabic numbers. This is the default format: 0, 1, 2, 3, ... `0...0' Decimal numbers with as many digits as specified. So, `00' would result in printing numbers as 01, 02, 03, ... In fact, any digit instead of zero does work; `gtroff' only counts how many digits are specified. As a consequence, `af''s default format `1' could be specified as `0' also (and exactly this is returned by the `\g' escape, see below). `I' Upper-case Roman numerals: 0, I, II, III, IV, ... `i' Lower-case Roman numerals: 0, i, ii, iii, iv, ... `A' Upper-case letters: 0, A, B, C, ..., Z, AA, AB, ... `a' Lower-case letters: 0, a, b, c, ..., z, aa, ab, ... Omitting the number register format causes a warning of type `missing'. *Note Debugging::, for more details. Specifying a nonexistent format causes an error. The following example produces `10, X, j, 010': .nr a 10 .af a 1 \" the default format \na, .af a I \na, .af a a \na, .af a 001 \na The largest number representable for the `i' and `I' formats is 39999 (or -39999); UNIX `troff' uses `z' and `w' to represent 10000 and 5000 in Roman numerals, and so does `gtroff'. Currently, the correct glyphs of Roman numeral five thousand and Roman numeral ten thousand (Unicode code points `U+2182' and `U+2181', respectively) are not available. If IDENT doesn't exist, it is created. Changing the output format of a read-only register causes an error. It is necessary to first copy the register's value to a writeable register, then apply the `af' request to this other register. -- Escape: \gi -- Escape: \g(id -- Escape: \g[ident] Return the current format of the specified register IDENT (one-character name I, two-character name ID). For example, `\ga' after the previous example would produce the string `000'. If the register hasn't been defined yet, nothing is returned. 5.6.5 Built-in Registers ------------------------ The following lists some built-in registers which are not described elsewhere in this manual. Any register which begins with a `.' is read-only. A complete listing of all built-in registers can be found in *note Register Index::. `\n[.F]' This string-valued register returns the current input file name. `\n[.H]' Horizontal resolution in basic units. `\n[.R]' The number of number registers available. This is always 10000 in GNU `troff'; it exists for backward compatibility. `\n[.U]' If `gtroff' is called with the `-U' command line option to activate unsafe mode, the number register `.U' is set to 1, and to zero otherwise. *Note Groff Options::. `\n[.V]' Vertical resolution in basic units. `\n[seconds]' The number of seconds after the minute, normally in the range 0 to 59, but can be up to 61 to allow for leap seconds. Initialized at start-up of `gtroff'. `\n[minutes]' The number of minutes after the hour, in the range 0 to 59. Initialized at start-up of `gtroff'. `\n[hours]' The number of hours past midnight, in the range 0 to 23. Initialized at start-up of `gtroff'. `\n[dw]' Day of the week (1-7). `\n[dy]' Day of the month (1-31). `\n[mo]' Current month (1-12). `\n[year]' The current year. `\n[yr]' The current year minus 1900. Unfortunately, the documentation of UNIX Version 7's `troff' had a year 2000 bug: It incorrectly claimed that `yr' contains the last two digits of the year. That claim has never been true of either AT&T `troff' or GNU `troff'. Old `troff' input that looks like this: '\" The following line stopped working after 1999 This document was formatted in 19\n(yr. can be corrected as follows: This document was formatted in \n[year]. or, to be portable to older `troff' versions, as follows: .nr y4 1900+\n(yr This document was formatted in \n(y4. `\n[.c]' `\n[c.]' The current _input_ line number. Register `.c' is read-only, whereas `c.' (a `gtroff' extension) is writable also, affecting both `.c' and `c.'. `\n[ln]' The current _output_ line number after a call to the `nm' request to activate line numbering. *Note Miscellaneous::, for more information about line numbering. `\n[.x]' The major version number. For example, if the version number is 1.03 then `.x' contains `1'. `\n[.y]' The minor version number. For example, if the version number is 1.03 then `.y' contains `03'. `\n[.Y]' The revision number of `groff'. `\n[$$]' The process ID of `gtroff'. `\n[.g]' Always 1. Macros should use this to determine whether they are running under GNU `troff'. `\n[.A]' If the command line option `-a' is used to produce an ASCII approximation of the output, this is set to 1, zero otherwise. *Note Groff Options::. `\n[.O]' This read-only register is set to the suppression nesting level (see escapes `\O'). *Note Suppressing output::. `\n[.P]' This register is set to 1 (and to 0 otherwise) if the current page is actually being printed, i.e., if the `-o' option is being used to only print selected pages. *Note Groff Options::, for more information. `\n[.T]' If `gtroff' is called with the `-T' command line option, the number register `.T' is set to 1, and zero otherwise. *Note Groff Options::. `\*[.T]' A single read-write string register which contains the current output device (for example, `latin1' or `ps'). This is the only string register defined by `gtroff'. 5.7 Manipulating Filling and Adjusting ====================================== Various ways of causing "breaks" were given in *note Implicit Line Breaks::. The `br' request likewise causes a break. Several other requests also cause breaks, but implicitly. These are `bp', `ce', `cf', `fi', `fl', `in', `nf', `rj', `sp', `ti', and `trf'. -- Request: .br Break the current line, i.e., the input collected so far is emitted without adjustment. If the no-break control character is used, `gtroff' suppresses the break: a 'br b => a b Initially, `gtroff' fills and adjusts text to both margins. Filling can be disabled via the `nf' request and re-enabled with the `fi' request. -- Request: .fi -- Register: \n[.u] Activate fill mode (which is the default). This request implicitly enables adjusting; it also inserts a break in the text currently being filled. The read-only number register `.u' is set to 1. The fill mode status is associated with the current environment (*note Environments::). See *note Line Control::, for interaction with the `\c' escape. -- Request: .nf Activate no-fill mode. Input lines are output as-is, retaining line breaks and ignoring the current line length. This command implicitly disables adjusting; it also causes a break. The number register `.u' is set to 0. The fill mode status is associated with the current environment (*note Environments::). See *note Line Control::, for interaction with the `\c' escape. -- Request: .ad [mode] -- Register: \n[.j] Set adjusting mode. Activation and deactivation of adjusting is done implicitly with calls to the `fi' or `nf' requests. MODE can have one of the following values: `l' Adjust text to the left margin. This produces what is traditionally called ragged-right text. `r' Adjust text to the right margin, producing ragged-left text. `c' Center filled text. This is different to the `ce' request which only centers text without filling. `b' `n' Justify to both margins. This is the default used by `gtroff'. Finally, MODE can be the numeric argument returned by the `.j' register. Using `ad' without argument is the same as saying `.ad \[.j]'. In particular, `gtroff' adjusts lines in the same way it did before adjusting was deactivated (with a call to `na', say). For example, this input code .de AD . br . ad \\$1 .. . .de NA . br . na .. . textA .AD r .nr ad \n[.j] textB .AD c textC .NA textD .AD \" back to centering textE .AD \n[ad] \" back to right justifying textF produces the following output: textA textB textC textD textE textF As just demonstrated, the current adjustment mode is available in the read-only number register `.j'; it can be stored and subsequently used to set adjustment. The adjustment mode status is associated with the current environment (*note Environments::). -- Request: .na Disable adjusting. This request won't change the current adjustment mode: A subsequent call to `ad' uses the previous adjustment setting. The adjustment mode status is associated with the current environment (*note Environments::). -- Request: .brp -- Escape: \p Adjust the current line and cause a break. In most cases this produces very ugly results since `gtroff' doesn't have a sophisticated paragraph building algorithm (as TeX have, for example); instead, `gtroff' fills and adjusts a paragraph line by line: This is an uninteresting sentence. This is an uninteresting sentence.\p This is an uninteresting sentence. is formatted as This is an uninteresting sentence. This is an uninteresting sentence. This is an uninteresting sentence. -- Request: .ss word_space_size [sentence_space_size] -- Register: \n[.ss] -- Register: \n[.sss] Change the size of a space between words. It takes its units as one twelfth of the space width parameter for the current font. Initially both the WORD_SPACE_SIZE and SENTENCE_SPACE_SIZE are 12. In fill mode, the values specify the minimum distance. If two arguments are given to the `ss' request, the second argument sets the sentence space size. If the second argument is not given, sentence space size is set to WORD_SPACE_SIZE. The sentence space size is used in two circumstances: If the end of a sentence occurs at the end of a line in fill mode, then both an inter-word space and a sentence space are added; if two spaces follow the end of a sentence in the middle of a line, then the second space is a sentence space. If a second argument is never given to the `ss' request, the behaviour of UNIX `troff' is the same as that exhibited by GNU `troff'. In GNU `troff', as in UNIX `troff', a sentence should always be followed by either a newline or two spaces. The read-only number registers `.ss' and `.sss' hold the values of the parameters set by the first and second arguments of the `ss' request. The word space and sentence space values are associated with the current environment (*note Environments::). Contrary to AT&T `troff', this request is _not_ ignored if a TTY output device is used; the given values are then rounded down to a multiple of 12 (*note Implementation Differences::). The request is ignored if there is no parameter. Another useful application of the `ss' request is to insert discardable horizontal space, i.e., space which is discarded at a line break. For example, paragraph-style footnotes could be separated this way: .ll 4.5i 1.\ This is the first footnote.\c .ss 48 .nop .ss 12 2.\ This is the second footnote. The result: 1. This is the first footnote. 2. This is the second footnote. Note that the `\h' escape produces unbreakable space. -- Request: .ce [nnn] -- Register: \n[.ce] Center text. While the `.ad c' request also centers text, it fills the text as well. `ce' does not fill the text it affects. This request causes a break. The number of lines still to be centered is associated with the current environment (*note Environments::). The following example demonstrates the differences. Here the input: .ll 4i .ce 1000 This is a small text fragment which shows the differences between the `.ce' and the `.ad c' request. .ce 0 .ad c This is a small text fragment which shows the differences between the `.ce' and the `.ad c' request. And here the result: This is a small text fragment which shows the differences between the `.ce' and the `.ad c' request. This is a small text fragment which shows the differences between the `.ce' and the `.ad c' request. With no arguments, `ce' centers the next line of text. NNN specifies the number of lines to be centered. If the argument is zero or negative, centering is disabled. The basic length for centering text is the line length (as set with the `ll' request) minus the indentation (as set with the `in' request). Temporary indentation is ignored. As can be seen in the previous example, it is a common idiom to turn on centering for a large number of lines, and to turn off centering after text to be centered. This is useful for any request which takes a number of lines as an argument. The `.ce' read-only number register contains the number of lines remaining to be centered, as set by the `ce' request. -- Request: .rj [nnn] -- Register: \n[.rj] Justify unfilled text to the right margin. Arguments are identical to the `ce' request. The `.rj' read-only number register is the number of lines to be right-justified as set by the `rj' request. This request causes a break. The number of lines still to be right-justified is associated with the current environment (*note Environments::). 5.8 Manipulating Hyphenation ============================ Here a description of requests which influence hyphenation. -- Request: .hy [mode] -- Register: \n[.hy] Enable hyphenation. The request has an optional numeric argument, MODE, to restrict hyphenation if necessary: `1' The default argument if MODE is omitted. Hyphenate without restrictions. This is also the start-up value of `gtroff'. `2' Do not hyphenate the last word on a page or column. `4' Do not hyphenate the last two characters of a word. `8' Do not hyphenate the first two characters of a word. Values in the previous table are additive. For example, the value 12 causes `gtroff' to neither hyphenate the last two nor the first two characters of a word. The current hyphenation restrictions can be found in the read-only number register `.hy'. The hyphenation mode is associated with the current environment (*note Environments::). -- Request: .nh Disable hyphenation (i.e., set the hyphenation mode to zero). Note that the hyphenation mode of the last call to `hy' is not remembered. The hyphenation mode is associated with the current environment (*note Environments::). -- Request: .hlm [nnn] -- Register: \n[.hlm] -- Register: \n[.hlc] Set the maximum number of consecutive hyphenated lines to NNN. If this number is negative, there is no maximum. The default value is -1 if NNN is omitted. This value is associated with the current environment (*note Environments::). Only lines output from a given environment count towards the maximum associated with that environment. Hyphens resulting from `\%' are counted; explicit hyphens are not. The current setting of `hlm' is available in the `.hlm' read-only number register. Also the number of immediately preceding consecutive hyphenated lines are available in the read-only number register `.hlc'. -- Request: .hw word1 word2 ... Define how WORD1, WORD2, etc. are to be hyphenated. The words must be given with hyphens at the hyphenation points. For example: .hw in-sa-lub-rious Besides the space character, any character whose hyphenation code value is zero can be used to separate the arguments of `hw' (see the documentation for the `hcode' request below for more information). In addition, this request can be used more than once. Hyphenation exceptions specified with the `hw' request are associated with the current hyphenation language; it causes an error if there is no current hyphenation language. This request is ignored if there is no parameter. In old versions of `troff' there was a limited amount of space to store such information; fortunately, with `gtroff', this is no longer a restriction. -- Escape: \% -- Escape: \: To tell `gtroff' how to hyphenate words on the fly, use the `\%' escape, also known as the "hyphenation character". Preceding a word with this character prevents it from being hyphenated; putting it inside a word indicates to `gtroff' that the word may be hyphenated at that point. Note that this mechanism only affects that one occurrence of the word; to change the hyphenation of a word for the entire document, use the `hw' request. The `\:' escape inserts a zero-width break point (that is, the word breaks but without adding a hyphen). ... check the /var/log/\:httpd/\:access_log file ... Note that `\X' and `\Y' start a word, that is, the `\%' escape in (say) `\X'...'\%foobar' and `\Y'...'\%foobar' no longer prevents hyphenation but inserts a hyphenation point at the beginning of `foobar'; most likely this isn't what you want to do. -- Request: .hc [char] Change the hyphenation character to CHAR. This character then works the same as the `\%' escape, and thus, no longer appears in the output. Without an argument, `hc' resets the hyphenation character to be `\%' (the default) only. The hyphenation character is associated with the current environment (*note Environments::). -- Request: .hpf pattern_file -- Request: .hpfa pattern_file -- Request: .hpfcode a b [c d ...] Read in a file of hyphenation patterns. This file is searched for in the same way as `NAME.tmac' (or `tmac.NAME') is searched for if the `-mNAME' option is specified. It should have the same format as (simple) TeX patterns files. More specifically, the following scanning rules are implemented. * A percent sign starts a comment (up to the end of the line) even if preceded by a backslash. * No support for `digraphs' like `\$'. * `^^XX' (X is 0-9 or a-f) and `^^X' (character code of X in the range 0-127) are recognized; other use of `^' causes an error. * No macro expansion. * `hpf' checks for the expression `\patterns{...}' (possibly with whitespace before and after the braces). Everything between the braces is taken as hyphenation patterns. Consequently, `{' and `}' are not allowed in patterns. * Similarly, `\hyphenation{...}' gives a list of hyphenation exceptions. * `\endinput' is recognized also. * For backwards compatibility, if `\patterns' is missing, the whole file is treated as a list of hyphenation patterns (only recognizing the `%' character as the start of a comment). If no `hpf' request is specified (either in the document or in a macro package), `gtroff' won't hyphenate at all. The `hpfa' request appends a file of patterns to the current list. The `hpfcode' request defines mapping values for character codes in hyphenation patterns. `hpf' or `hpfa' then apply the mapping (after reading the patterns) before replacing or appending them to the current list of patterns. Its arguments are pairs of character codes - integers from 0 to 255. The request maps character code A to code B, code C to code D, and so on. You can use character codes which would be invalid otherwise. By default, everything maps to itself except letters `A' to `Z' which map to `a' to `z'. The set of hyphenation patterns is associated with the current language set by the `hla' request. The `hpf' request is usually invoked by the `troffrc' or `troffrc-end' file; by default, `troffrc' loads hyphenation patterns and exceptions for American English (in files `hyphen.us' and `hyphenex.us'). A second call to `hpf' (for the same language) replaces the hyphenation patterns with the new ones. Invoking `hpf' causes an error if there is no current hyphenation language. -- Request: .hcode c1 code1 [c2 code2 ...] Set the hyphenation code of character C1 to CODE1, that of C2 to CODE2, etc. A hyphenation code must be a single input character (not a special character) other than a digit or a space. To make hyphenation work, hyphenation codes must be set up. At start-up, groff only assigns hyphenation codes to the letters `a'-`z' (mapped to themselves) and to the letters `A'-`Z' (mapped to `a'-`z'); all other hyphenation codes are set to zero. Normally, hyphenation patterns contain only lowercase letters which should be applied regardless of case. In other words, the words `FOO' and `Foo' should be hyphenated exactly the same way as the word `foo' is hyphenated, and this is what `hcode' is good for. Words which contain other letters won't be hyphenated properly if the corresponding hyphenation patterns actually do contain them. For example, the following `hcode' requests are necessary to assign hyphenation codes to the letters `ÄäÖöÜüß' (this is needed for German): .hcode ä ä Ä ä .hcode ö ö Ö ö .hcode ü ü Ü ü .hcode ß ß Without those assignments, groff treats German words like `Kindergärten' (the plural form of `kindergarten') as two substrings `kinderg' and `rten' because the hyphenation code of the umlaut a is zero by default. There is a German hyphenation pattern which covers `kinder', so groff finds the hyphenation `kin-der'. The other two hyphenation points (`kin-der-gär-ten') are missed. This request is ignored if it has no parameter. -- Request: .hym [length] -- Register: \n[.hym] Set the (right) hyphenation margin to LENGTH. If the current adjustment mode is not `b' or `n', the line is not hyphenated if it is shorter than LENGTH. Without an argument, the hyphenation margin is reset to its default value, which is 0. The default scaling indicator for this request is `m'. The hyphenation margin is associated with the current environment (*note Environments::). A negative argument resets the hyphenation margin to zero, emitting a warning of type `range'. The current hyphenation margin is available in the `.hym' read-only number register. -- Request: .hys [hyphenation_space] -- Register: \n[.hys] Set the hyphenation space to HYPHENATION_SPACE. If the current adjustment mode is `b' or `n', don't hyphenate the line if it can be justified by adding no more than HYPHENATION_SPACE extra space to each word space. Without argument, the hyphenation space is set to its default value, which is 0. The default scaling indicator for this request is `m'. The hyphenation space is associated with the current environment (*note Environments::). A negative argument resets the hyphenation space to zero, emitting a warning of type `range'. The current hyphenation space is available in the `.hys' read-only number register. -- Request: .shc [glyph] Set the "soft hyphen character" to GLYPH.(1) (*note Manipulating Hyphenation-Footnote-1::) If the argument is omitted, the soft hyphen character is set to the default glyph `\(hy' (this is the start-up value of `gtroff' also). The soft hyphen character is the glyph that is inserted when a word is hyphenated at a line break. If the soft hyphen character does not exist in the font of the character immediately preceding a potential break point, then the line is not broken at that point. Neither definitions (specified with the `char' request) nor translations (specified with the `tr' request) are considered when finding the soft hyphen character. -- Request: .hla language -- Register: \n[.hla] Set the current hyphenation language to the string LANGUAGE. Hyphenation exceptions specified with the `hw' request and hyphenation patterns specified with the `hpf' and `hpfa' requests are both associated with the current hyphenation language. The `hla' request is usually invoked by the `troffrc' or the `troffrc-end' files; `troffrc' sets the default language to `us'. The current hyphenation language is available as a string in the read-only number register `.hla'. .ds curr_language \n[.hla] \*[curr_language] => us (1) "Soft hyphen character" is a misnomer since it is an output glyph. 5.9 Manipulating Spacing ======================== -- Request: .sp [distance] Space downwards DISTANCE. With no argument it advances 1 line. A negative argument causes `gtroff' to move up the page the specified distance. If the argument is preceded by a `|' then `gtroff' moves that distance from the top of the page. This request causes a line break, and that adds the current line spacing to the space you have just specified. The default scaling indicator is `v'. For convenience you may wish to use the following macros to set the height of the next line at a given distance from the top or the bottom of the page: .de y-from-top-down . sp |\\$1-\\n[.v]u .. . .de y-from-bot-up . sp |\\n[.p]u-\\$1-\\n[.v]u .. A call to `.y-from-bot-up 10c' means that the bottom of the next line will be at 10cm from the paper edge at the bottom. If a vertical trap is sprung during execution of `sp', the amount of vertical space after the trap is discarded. For example, this .de xxx .. . .wh 0 xxx . .pl 5v foo .sp 2 bar .sp 50 baz results in foo bar baz The amount of discarded space is available in the number register `.trunc'. To protect `sp' against vertical traps, use the `vpt' request: .vpt 0 .sp -3 .vpt 1 -- Request: .ls [nnn] -- Register: \n[.L] Output NNN-1 blank lines after each line of text. With no argument, `gtroff' uses the previous value before the last `ls' call. .ls 2 \" This causes double-spaced output .ls 3 \" This causes triple-spaced output .ls \" Again double-spaced The line spacing is associated with the current environment (*note Environments::). The read-only number register `.L' contains the current line spacing setting. *Note Changing Type Sizes::, for the requests `vs' and `pvs' as alternatives to `ls'. -- Escape: \x'spacing' -- Register: \n[.a] Sometimes, extra vertical spacing is only needed occasionally, e.g. to allow space for a tall construct (like an equation). The `\x' escape does this. The escape is given a numerical argument, usually enclosed in quotes (like `\x'3p''); the default scaling indicator is `v'. If this number is positive extra vertical space is inserted below the current line. A negative number adds space above. If this escape is used multiple times on the same line, the maximum of the values is used. *Note Escapes::, for details on parameter delimiting characters. The `.a' read-only number register contains the most recent (nonnegative) extra vertical line space. Using `\x' can be necessary in combination with the `\b' escape, as the following example shows. This is a test with the \[rs]b escape. .br This is a test with the \[rs]b escape. .br This is a test with \b'xyz'\x'-1m'\x'1m'. .br This is a test with the \[rs]b escape. .br This is a test with the \[rs]b escape. produces This is a test with the \b escape. This is a test with the \b escape. x This is a test with y. z This is a test with the \b escape. This is a test with the \b escape. -- Request: .ns -- Request: .rs -- Register: \n[.ns] Enable "no-space mode". In this mode, spacing (either via `sp' or via blank lines) is disabled. The `bp' request to advance to the next page is also disabled, except if it is accompanied by a page number (see *note Page Control::, for more information). This mode ends when actual text is output or the `rs' request is encountered which ends no-space mode. The read-only number register `.ns' is set to 1 as long as no-space mode is active. This request is useful for macros that conditionally insert vertical space before the text starts (for example, a paragraph macro could insert some space except when it is the first paragraph after a section header). 5.10 Tabs and Fields ==================== A tab character (ASCII char 9, EBCDIC char 5) causes a horizontal movement to the next tab stop (much like it did on a typewriter). -- Escape: \t This escape is a non-interpreted tab character. In copy mode (*note Copy-in Mode::), `\t' is the same as a real tab character. -- Request: .ta [n1 n2 ... nn T r1 r2 ... rn] -- Register: \n[.tabs] Change tab stop positions. This request takes a series of tab specifiers as arguments (optionally divided into two groups with the letter `T') which indicate where each tab stop is to be (overriding any previous settings). Tab stops can be specified absolutely, i.e., as the distance from the left margin. For example, the following sets 6 tab stops every one inch. .ta 1i 2i 3i 4i 5i 6i Tab stops can also be specified using a leading `+' which means that the specified tab stop is set relative to the previous tab stop. For example, the following is equivalent to the previous example. .ta 1i +1i +1i +1i +1i +1i `gtroff' supports an extended syntax to specify repeat values after the `T' mark (these values are always taken as relative) - this is the usual way to specify tabs set at equal intervals. The following is, yet again, the same as the previous examples. It does even more since it defines an infinite number of tab stops separated by one inch. .ta T 1i Now we are ready to interpret the full syntax given at the beginning: Set tabs at positions N1, N2, ..., NN and then set tabs at NN+R1, NN+R2, ..., NN+RN and then at NN+RN+R1, NN+RN+R2, ..., NN+RN+RN, and so on. Example: `4c +6c T 3c 5c 2c' is equivalent to `4c 10c 13c 18c 20c 23c 28c 30c ...'. The material in each tab column (i.e., the column between two tab stops) may be justified to the right or left or centered in the column. This is specified by appending `R', `L', or `C' to the tab specifier. The default justification is `L'. Example: .ta 1i 2iC 3iR Some notes: * The default unit of the `ta' request is `m'. * A tab stop is converted into a non-breakable horizontal movement which can be neither stretched nor squeezed. For example, .ds foo a\tb\tc .ta T 5i \*[foo] creates a single line which is a bit longer than 10 inches (a string is used to show exactly where the tab characters are). Now consider the following: .ds bar a\tb b\tc .ta T 5i \*[bar] `gtroff' first converts the tab stops of the line into unbreakable horizontal movements, then splits the line after the second `b' (assuming a sufficiently short line length). Usually, this isn't what the user wants. * Superfluous tabs (i.e., tab characters which do not correspond to a tab stop) are ignored except the first one which delimits the characters belonging to the last tab stop for right-justifying or centering. Consider the following example .ds Z foo\tbar\tfoo .ds ZZ foo\tbar\tfoobar .ds ZZZ foo\tbar\tfoo\tbar .ta 2i 4iR \*[Z] .br \*[ZZ] .br \*[ZZZ] .br which produces the following output: foo bar foo foo bar foobar foo bar foobar The first line right-justifies the second `foo' relative to the tab stop. The second line right-justifies `foobar'. The third line finally right-justifies only `foo' because of the additional tab character which marks the end of the string belonging to the last defined tab stop. * Tab stops are associated with the current environment (*note Environments::). * Calling `ta' without an argument removes all tab stops. * The start-up value of `gtroff' is `T 0.8i'. The read-only number register `.tabs' contains a string representation of the current tab settings suitable for use as an argument to the `ta' request. .ds tab-string \n[.tabs] \*[tab-string] => T120u The `troff' version of the Plan 9 operating system uses register `.S' for the same purpose. -- Request: .tc [fill-glyph] Normally `gtroff' fills the space to the next tab stop with whitespace. This can be changed with the `tc' request. With no argument `gtroff' reverts to using whitespace, which is the default. The value of this "tab repetition character" is associated with the current environment (*note Environments::).(1) (*note Tabs and Fields-Footnote-1::) -- Request: .linetabs n -- Register: \n[.linetabs] If N is missing or not zero, enable "line-tabs" mode, or disable it otherwise (the default). In line-tabs mode, `gtroff' computes tab distances relative to the (current) output line instead of the input line. For example, the following code: .ds x a\t\c .ds y b\t\c .ds z c .ta 1i 3i \*x \*y \*z in normal mode, results in the output a b c in line-tabs mode, the same code outputs a b c Line-tabs mode is associated with the current environment. The read-only register `.linetabs' is set to 1 if in line-tabs mode, and 0 in normal mode. (1) "Tab repetition character" is a misnomer since it is an output glyph. 5.10.1 Leaders -------------- Sometimes it may may be desirable to use the `tc' request to fill a particular tab stop with a given glyph (for example dots in a table of contents), but also normal tab stops on the rest of the line. For this `gtroff' provides an alternate tab mechanism, called "leaders" which does just that. A leader character (character code 1) behaves similarly to a tab character: It moves to the next tab stop. The only difference is that for this movement, the fill glyph defaults to a period character and not to space. -- Escape: \a This escape is a non-interpreted leader character. In copy mode (*note Copy-in Mode::), `\a' is the same as a real leader character. -- Request: .lc [fill-glyph] Declare the "leader repetition character".(1) (*note Leaders-Footnote-1::) Without an argument, leaders act the same as tabs (i.e., using whitespace for filling). `gtroff''s start-up value is a dot (`.'). The value of the leader repetition character is associated with the current environment (*note Environments::). For a table of contents, to name an example, tab stops may be defined so that the section number is one tab stop, the title is the second with the remaining space being filled with a line of dots, and then the page number slightly separated from the dots. .ds entry 1.1\tFoo\a\t12 .lc . .ta 1i 5i +.25i \*[entry] This produces 1.1 Foo.......................................... 12 (1) "Leader repetition character" is a misnomer since it is an output glyph. 5.10.2 Fields ------------- "Fields" are a more general way of laying out tabular data. A field is defined as the data between a pair of "delimiting characters". It contains substrings which are separated by "padding characters". The width of a field is the distance on the _input_ line from the position where the field starts to the next tab stop. A padding character inserts stretchable space similar to TeX's `\hss' command (thus it can even be negative) to make the sum of all substring lengths plus the stretchable space equal to the field width. If more than one padding character is inserted, the available space is evenly distributed among them. -- Request: .fc [delim-char [padding-char]] Define a delimiting and a padding character for fields. If the latter is missing, the padding character defaults to a space character. If there is no argument at all, the field mechanism is disabled (which is the default). Note that contrary to e.g. the tab repetition character, delimiting and padding characters are _not_ associated to the current environment (*note Environments::). Example: .fc # ^ .ta T 3i #foo^bar^smurf# .br #foo^^bar^smurf# and here the result: foo bar smurf foo bar smurf 5.11 Character Translations =========================== The control character (`.') and the no-break control character (`'') can be changed with the `cc' and `c2' requests, respectively. -- Request: .cc [c] Set the control character to C. With no argument the default control character `.' is restored. The value of the control character is associated with the current environment (*note Environments::). -- Request: .c2 [c] Set the no-break control character to C. With no argument the default control character `'' is restored. The value of the no-break control character is associated with the current environment (*note Environments::). *Note Requests::. -- Request: .eo Disable the escape mechanism completely. After executing this request, the backslash character `\' no longer starts an escape sequence. This request can be very helpful in writing macros since it is not necessary then to double the escape character. Here an example: .\" This is a simplified version of the .\" .BR request from the man macro package .eo .de BR . ds result \& . while (\n[.$] >= 2) \{\ . as result \fB\$1\fR\$2 . shift 2 . \} . if \n[.$] .as result \fB\$1 \*[result] . ft R .. .ec -- Request: .ec [c] Set the escape character to C. With no argument the default escape character `\' is restored. It can be also used to re-enable the escape mechanism after an `eo' request. Note that changing the escape character globally likely breaks macro packages since `gtroff' has no mechanism to `intern' macros, i.e., to convert a macro definition into an internal form which is independent of its representation (TeX has this mechanism). If a macro is called, it is executed literally. -- Request: .ecs -- Request: .ecr The `ecs' request saves the current escape character in an internal register. Use this request in combination with the `ec' request to temporarily change the escape character. The `ecr' request restores the escape character saved with `ecs'. Without a previous call to `ecs', this request sets the escape character to `\'. -- Escape: \\ -- Escape: \e -- Escape: \E Print the current escape character (which is the backslash character `\' by default). `\\' is a `delayed' backslash; more precisely, it is the default escape character followed by a backslash, which no longer has special meaning due to the leading escape character. It is _not_ an escape sequence in the usual sense! In any unknown escape sequence `\X' the escape character is ignored and X is printed. But if X is equal to the current escape character, no warning is emitted. As a consequence, only at top-level or in a diversion a backslash glyph is printed; in copy-in mode, it expands to a single backslash which then combines with the following character to an escape sequence. The `\E' escape differs from `\e' by printing an escape character that is not interpreted in copy mode. Use this to define strings with escapes that work when used in copy mode (for example, as a macro argument). The following example defines strings to begin and end a superscript: .ds { \v'-.3m'\s'\En[.s]*60/100' .ds } \s0\v'.3m' Another example to demonstrate the differences between the various escape sequences, using a strange escape character, `-'. .ec - .de xxx --A'123' .. .xxx => -A'foo' The result is surprising for most users, expecting `1' since `foo' is a valid identifier. What has happened? As mentioned above, the leading escape character makes the following character ordinary. Written with the default escape character the sequence `--' becomes `\-' - this is the minus sign. If the escape character followed by itself is a valid escape sequence, only `\E' yields the expected result: .ec - .de xxx -EA'123' .. .xxx => 1 -- Escape: \. Similar to `\\', the sequence `\.' isn't a real escape sequence. As before, a warning message is suppressed if the escape character is followed by a dot, and the dot itself is printed. .de foo . nop foo . . de bar . nop bar \\.. . .. .foo .bar => foo bar The first backslash is consumed while the macro is read, and the second is swallowed while executing macro `foo'. A "translation" is a mapping of an input character to an output glyph. The mapping occurs at output time, i.e., the input character gets assigned the metric information of the mapped output character right before input tokens are converted to nodes (*note Gtroff Internals::, for more on this process). -- Request: .tr abcd... -- Request: .trin abcd... Translate character A to glyph B, character C to glyph D, etc. If there is an odd number of arguments, the last one is translated to an unstretchable space (`\ '). The `trin' request is identical to `tr', but when you unformat a diversion with `asciify' it ignores the translation. *Note Diversions::, for details about the `asciify' request. Some notes: * Special characters (`\(XX', `\[XXX]', `\C'XXX'', `\'', `\`', `\-', `\_'), glyphs defined with the `char' request, and numbered glyphs (`\N'XXX'') can be translated also. * The `\e' escape can be translated also. * Characters can be mapped onto the `\%' and `\~' escapes (but `\%' and `\~' can't be mapped onto another glyph). * The following characters can't be translated: space (with one exception, see below), backspace, newline, leader (and `\a'), tab (and `\t'). * Translations are not considered for finding the soft hyphen character set with the `shc' request. * The pair `C\&' (this is an arbitrary character C followed by the zero width space character) maps this character to nothing. .tr a\& foo bar => foo br It is even possible to map the space character to nothing: .tr aa \& foo bar => foobar As shown in the example, the space character can't be the first character/glyph pair as an argument of `tr'. Additionally, it is not possible to map the space character to any other glyph; requests like `.tr aa x' undo `.tr aa \&' instead. If justification is active, lines are justified in spite of the `empty' space character (but there is no minimal distance, i.e. the space character, between words). * After an output glyph has been constructed (this happens at the moment immediately before the glyph is appended to an output glyph list, either by direct output, in a macro, diversion, or string), it is no longer affected by `tr'. * Translating character to glyphs where one of them or both are undefined is possible also; `tr' does not check whether the entities in its argument do exist. *Note Gtroff Internals::. * `troff' no longer has a hard-coded dependency on Latin-1; all `charXXX' entities have been removed from the font description files. This has a notable consequence which shows up in warnings like `can't find character with input code XXX' if the `tr' request isn't handled properly. Consider the following translation: .tr éÉ This maps input character `é' onto glyph `É', which is identical to glyph `char201'. But this glyph intentionally doesn't exist! Instead, `\[char201]' is treated as an input character entity and is by default mapped onto `\['E]', and `gtroff' doesn't handle translations of translations. The right way to write the above translation is .tr é\['E] In other words, the first argument of `tr' should be an input character or entity, and the second one a glyph entity. * Without an argument, the `tr' request is ignored. -- Request: .trnt abcd... `trnt' is the same as the `tr' request except that the translations do not apply to text that is transparently throughput into a diversion with `\!'. *Note Diversions::, for more information. For example, .tr ab .di x \!.tm a .di .x prints `b' to the standard error stream; if `trnt' is used instead of `tr' it prints `a'. 5.12 Troff and Nroff Mode ========================= Originally, `nroff' and `troff' were two separate programs, the former for TTY output, the latter for everything else. With GNU `troff', both programs are merged into one executable, sending its output to a device driver (`grotty' for TTY devices, `grops' for POSTSCRIPT, etc.) which interprets the intermediate output of `gtroff'. For UNIX `troff' it makes sense to talk about "Nroff mode" and "Troff mode" since the differences are hardcoded. For GNU `troff', this distinction is not appropriate because `gtroff' simply takes the information given in the font files for a particular device without handling requests specially if a TTY output device is used. Usually, a macro package can be used with all output devices. Nevertheless, it is sometimes necessary to make a distinction between TTY and non-TTY devices: `gtroff' provides two built-in conditions `n' and `t' for the `if', `ie', and `while' requests to decide whether `gtroff' shall behave like `nroff' or like `troff'. -- Request: .troff Make the `t' built-in condition true (and the `n' built-in condition false) for `if', `ie', and `while' conditional requests. This is the default if `gtroff' (_not_ `groff') is started with the `-R' switch to avoid loading of the start-up files `troffrc' and `troffrc-end'. Without `-R', `gtroff' stays in troff mode if the output device is not a TTY (e.g. `ps'). -- Request: .nroff Make the `n' built-in condition true (and the `t' built-in condition false) for `if', `ie', and `while' conditional requests. This is the default if `gtroff' uses a TTY output device; the code for switching to nroff mode is in the file `tty.tmac' which is loaded by the start-up file `troffrc'. *Note Conditionals and Loops::, for more details on built-in conditions. 5.13 Line Layout ================ The following drawing shows the dimensions which `gtroff' uses for placing a line of output onto the page. They are labeled with the request which manipulates each dimension. -->| in |<-- |<-----------ll------------>| +----+----+----------------------+----+ | : : : | +----+----+----------------------+----+ -->| po |<-- |<--------paper width---------------->| These dimensions are: `po' "Page offset" - this is the leftmost position of text on the final output, defining the "left margin". `in' "Indentation" - this is the distance from the left margin where text is printed. `ll' "Line length" - this is the distance from the left margin to right margin. A simple demonstration: .ll 3i This is text without indentation. The line length has been set to 3\~inch. .in +.5i .ll -.5i Now the left and right margins are both increased. .in .ll Calling .in and .ll without parameters restore the previous values. Result: This is text without indenta- tion. The line length has been set to 3 inch. Now the left and right margins are both increased. Calling .in and .ll without parameters restore the previ- ous values. -- Request: .po [offset] -- Request: .po +offset -- Request: .po -offset -- Register: \n[.o] Set horizontal page offset to OFFSET (or increment or decrement the current value by OFFSET). Note that this request does not cause a break, so changing the page offset in the middle of text being filled may not yield the expected result. The initial value is 1i. For TTY output devices, it is set to 0 in the startup file `troffrc'; the default scaling indicator is `m' (and not `v' as incorrectly documented in the original UNIX troff manual). The current page offset can be found in the read-only number register `.o'. If `po' is called without an argument, the page offset is reset to the previous value before the last call to `po'. .po 3i \n[.o] => 720 .po -1i \n[.o] => 480 .po \n[.o] => 720 -- Request: .in [indent] -- Request: .in +indent -- Request: .in -indent -- Register: \n[.i] Set indentation to INDENT (or increment or decrement the current value by INDENT). This request causes a break. Initially, there is no indentation. If `in' is called without an argument, the indentation is reset to the previous value before the last call to `in'. The default scaling indicator is `m'. The indentation is associated with the current environment (*note Environments::). If a negative indentation value is specified (which is not allowed), `gtroff' emits a warning of type `range' and sets the indentation to zero. The effect of `in' is delayed until a partially collected line (if it exists) is output. A temporary indentation value is reset to zero also. The current indentation (as set by `in') can be found in the read-only number register `.i'. -- Request: .ti offset -- Request: .ti +offset -- Request: .ti -offset -- Register: \n[.in] Temporarily indent the next output line by OFFSET. If an increment or decrement value is specified, adjust the temporary indentation relative to the value set by the `in' request. This request causes a break; its value is associated with the current environment (*note Environments::). The default scaling indicator is `m'. A call of `ti' without an argument is ignored. If the total indentation value is negative (which is not allowed), `gtroff' emits a warning of type `range' and sets the temporary indentation to zero. `Total indentation' is either OFFSET if specified as an absolute value, or the temporary plus normal indentation, if OFFSET is given as a relative value. The effect of `ti' is delayed until a partially collected line (if it exists) is output. The read-only number register `.in' is the indentation that applies to the current output line. The difference between `.i' and `.in' is that the latter takes into account whether a partially collected line still uses the old indentation value or a temporary indentation value is active. -- Request: .ll [length] -- Request: .ll +length -- Request: .ll -length -- Register: \n[.l] -- Register: \n[.ll] Set the line length to LENGTH (or increment or decrement the current value by LENGTH). Initially, the line length is set to 6.5i. The effect of `ll' is delayed until a partially collected line (if it exists) is output. The default scaling indicator is `m'. If `ll' is called without an argument, the line length is reset to the previous value before the last call to `ll'. If a negative line length is specified (which is not allowed), `gtroff' emits a warning of type `range' and sets the line length to zero. The line length is associated with the current environment (*note Environments::). The current line length (as set by `ll') can be found in the read-only number register `.l'. The read-only number register `.ll' is the line length that applies to the current output line. Similar to `.i' and `.in', the difference between `.l' and `.ll' is that the latter takes into account whether a partially collected line still uses the old line length value. 5.14 Line Control ================= It is important to understand how `gtroff' handles input and output lines. Many escapes use positioning relative to the input line. For example, this This is a \h'|1.2i'test. This is a \h'|1.2i'test. produces This is a test. This is a test. The main usage of this feature is to define macros which act exactly at the place where called. .\" A simple macro to underline a word .de underline . nop \\$1\l'|0\[ul]' .. In the above example, `|0' specifies a negative distance from the current position (at the end of the just emitted argument `\$1') back to the beginning of the input line. Thus, the `\l' escape draws a line from right to left. `gtroff' makes a difference between input and output line continuation; the latter is also called "interrupting" a line. -- Escape: \ -- Escape: \c -- Register: \n[.int] Continue a line. `\' (this is a backslash at the end of a line immediately followed by a newline) works on the input level, suppressing the effects of the following newline in the input. This is a \ .test => This is a .test The `|' operator is also affected. `\c' works on the output level. Anything after this escape on the same line is ignored, except `\R' which works as usual. Anything before `\c' on the same line is appended to the current partial output line. The next non-command line after an interrupted line counts as a new input line. The visual results depend on whether no-fill mode is active. * If no-fill mode is active (using the `nf' request), the next input text line after `\c' is handled as a continuation of the same input text line. .nf This is a \c test. => This is a test. * If fill mode is active (using the `fi' request), a word interrupted with `\c' is continued with the text on the next input text line, without an intervening space. This is a te\c st. => This is a test. Note that an intervening control line which causes a break is stronger than `\c', flushing out the current partial line in the usual way. The `.int' register contains a positive value if the last output line was interrupted with `\c'; this is associated with the current environment (*note Environments::). 5.15 Page Layout ================ `gtroff' provides some very primitive operations for controlling page layout. -- Request: .pl [length] -- Request: .pl +length -- Request: .pl -length -- Register: \n[.p] Set the "page length" to LENGTH (or increment or decrement the current value by LENGTH). This is the length of the physical output page. The default scaling indicator is `v'. The current setting can be found in the read-only number register `.p'. Note that this only specifies the size of the page, not the top and bottom margins. Those are not set by `gtroff' directly. *Note Traps::, for further information on how to do this. Negative `pl' values are possible also, but not very useful: No trap is sprung, and each line is output on a single page (thus suppressing all vertical spacing). If no argument or an invalid argument is given, `pl' sets the page length to 11i. `gtroff' provides several operations which help in setting up top and bottom titles (or headers and footers). -- Request: .tl 'left'center'right' Print a "title line". It consists of three parts: a left justified portion, a centered portion, and a right justified portion. The argument separator `'' can be replaced with any character not occurring in the title line. The `%' character is replaced with the current page number. This character can be changed with the `pc' request (see below). Without argument, `tl' is ignored. Some notes: * The line length set by the `ll' request is not honoured by `tl'; use the `lt' request (described below) instead, to control line length for text set by `tl'. * A title line is not restricted to the top or bottom of a page. * `tl' prints the title line immediately, ignoring a partially filled line (which stays untouched). * It is not an error to omit closing delimiters. For example, `.tl /foo' is equivalent to `.tl /foo///': It prints a title line with the left justified word `foo'; the centered and right justfied parts are empty. * `tl' accepts the same parameter delimiting characters as the `\A' escape; see *note Escapes::. -- Request: .lt [length] -- Request: .lt +length -- Request: .lt -length -- Register: \n[.lt] The title line is printed using its own line length, which is specified (or incremented or decremented) with the `lt' request. Initially, the title line length is set to 6.5i. If a negative line length is specified (which is not allowed), `gtroff' emits a warning of type `range' and sets the title line length to zero. The default scaling indicator is `m'. If `lt' is called without an argument, the title length is reset to the previous value before the last call to `lt'. The current setting of this is available in the `.lt' read-only number register; it is associated with the current environment (*note Environments::). -- Request: .pn page -- Request: .pn +page -- Request: .pn -page -- Register: \n[.pn] Change (increase or decrease) the page number of the _next_ page. The only argument is the page number; the request is ignored without a parameter. The read-only number register `.pn' contains the number of the next page: either the value set by a `pn' request, or the number of the current page plus 1. -- Request: .pc [char] Change the page number character (used by the `tl' request) to a different character. With no argument, this mechanism is disabled. Note that this doesn't affect the number register `%'. *Note Traps::. 5.16 Page Control ================= -- Request: .bp [page] -- Request: .bp +page -- Request: .bp -page -- Register: \n[%] Stop processing the current page and move to the next page. This request causes a break. It can also take an argument to set (increase, decrease) the page number of the next page (which actually becomes the current page after `bp' has finished). The difference between `bp' and `pn' is that `pn' does not cause a break or actually eject a page. *Note Page Layout::. .de newpage \" define macro 'bp \" begin page 'sp .5i \" vertical space .tl 'left top'center top'right top' \" title 'sp .3i \" vertical space .. \" end macro `bp' has no effect if not called within the top-level diversion (*note Diversions::). The read-write register `%' holds the current page number. The number register `.pe' is set to 1 while `bp' is active. *Note Page Location Traps::. -- Request: .ne [space] It is often necessary to force a certain amount of space before a new page occurs. This is most useful to make sure that there is not a single "orphan" line left at the bottom of a page. The `ne' request ensures that there is a certain distance, specified by the first argument, before the next page is triggered (see *note Traps::, for further information). The default scaling indicator for `ne' is `v'; the default value of SPACE is 1v if no argument is given. For example, to make sure that no fewer than 2 lines get orphaned, do the following before each paragraph: .ne 2 text text text `ne' then automatically causes a page break if there is space for one line only. -- Request: .sv [space] -- Request: .os `sv' is similar to the `ne' request; it reserves the specified amount of vertical space. If the desired amount of space exists before the next trap (or the bottom page boundary if no trap is set), the space is output immediately (ignoring a partially filled line which stays untouched). If there is not enough space, it is stored for later output via the `os' request. The default value is 1v if no argument is given; the default scaling indicator is `v'. Both `sv' and `os' ignore no-space mode. While the `sv' request allows negative values for SPACE, `os' ignores them. -- Register: \n[nl] This register contains the current vertical position. If the vertical position is zero and the top of page transition hasn't happened yet, `nl' is set to negative value. `gtroff' itself does this at the very beginning of a document before anything has been printed, but the main usage is to plant a header trap on a page if this page has already started. Consider the following: .de xxx . sp . tl ''Header'' . sp .. . First page. .bp .wh 0 xxx .nr nl (-1) Second page. Result: First page. ... Header Second page. ... Without resetting `nl' to a negative value, the just planted trap would be active beginning with the _next_ page, not the current one. *Note Diversions::, for a comparison with the `.h' and `.d' registers. 5.17 Fonts and Symbols ====================== `gtroff' can switch fonts at any point in the text. The basic set of fonts is `R', `I', `B', and `BI'. These are Times Roman, Italic, Bold, and Bold Italic. For non-TTY devices, there is also at least one symbol font which contains various special symbols (Greek, mathematics). 5.17.1 Changing Fonts --------------------- -- Request: .ft [font] -- Escape: \ff -- Escape: \f(fn -- Escape: \f[font] -- Register: \n[.sty] The `ft' request and the `\f' escape change the current font to FONT (one-character name F, two-character name FN). If FONT is a style name (as set with the `sty' request or with the `styles' command in the `DESC' file), use it within the current font family (as set with the `fam' request, `\F' escape, or with the `family' command in the `DESC' file). It is not possible to switch to a font with the name `DESC' (whereas this name could be used as a style name; however, this is not recommended). With no argument or using `P' as an argument, `.ft' switches to the previous font. Use `\f[]' to do this with the escape. The old syntax forms `\fP' or `\f[P]' are also supported. Fonts are generally specified as upper-case strings, which are usually 1 to 4 characters representing an abbreviation or acronym of the font name. This is no limitation, just a convention. The example below produces two identical lines. eggs, bacon, .ft B spam .ft and sausage. eggs, bacon, \fBspam\fP and sausage. Note that `\f' doesn't produce an input token in `gtroff'. As a consequence, it can be used in requests like `mc' (which expects a single character as an argument) to change the font on the fly: .mc \f[I]x\f[] The current style name is available in the read-only number register `.sty' (this is a string-valued register); if the current font isn't a style, the empty string is returned. It is associated with the current environment. *Note Font Positions::, for an alternative syntax. -- Request: .ftr f [g] Translate font F to font G. Whenever a font named F is referred to in a `\f' escape sequence, in the `F' and `S' conditional operators, or in the `ft', `ul', `bd', `cs', `tkf', `special', `fspecial', `fp', or `sty' requests, font G is used. If G is missing or equal to F the translation is undone. Note that it is not possible to chain font translations. Example: .ftr XXX TR .ftr XXX YYY .ft XXX => warning: can't find font `XXX' -- Request: .fzoom f [zoom] -- Register: \n[.zoom] Set magnification of font F to factor ZOOM, which must be a non-negative integer multiple of 1/1000th. This request is useful to adjust the optical size of a font in relation to the others. In the example below, font `CR' is magnified by 10% (the zoom factor is thus 1.1). .fam P .fzoom CR 1100 .ps 12 Palatino and \f[CR]Courier\f[] A missing or zero value of ZOOM is the same as a value of 1000, which means no magnification. F must be a real font name, not a style. Note that the magnification of a font is completely transparent to troff; a change of the zoom factor doesn't cause any effect except that the dimensions of glyphs, (word) spaces, kerns, etc., of the affected font are adjusted accordingly. The zoom factor of the current font is available in the read-only number register `.zoom', in multiples of 1/1000th. It returns zero if there is no magnification. 5.17.2 Font Families -------------------- Due to the variety of fonts available, `gtroff' has added the concept of "font families" and "font styles". The fonts are specified as the concatenation of the font family and style. Specifying a font without the family part causes `gtroff' to use that style of the current family. Currently, fonts for the devices `-Tps', `-Tpdf', `-Tdvi', `-Tlj4', `-Tlbp', and the X11 fonts are set up to this mechanism. By default, `gtroff' uses the Times family with the four styles `R', `I', `B', and `BI'. This way, it is possible to use the basic four fonts and to select a different font family on the command line (*note Groff Options::). -- Request: .fam [family] -- Register: \n[.fam] -- Escape: \Ff -- Escape: \F(fm -- Escape: \F[family] -- Register: \n[.fn] Switch font family to FAMILY (one-character name F, two-character name FM). If no argument is given, switch back to the previous font family. Use `\F[]' to do this with the escape. Note that `\FP' doesn't work; it selects font family `P' instead. The value at start-up is `T'. The current font family is available in the read-only number register `.fam' (this is a string-valued register); it is associated with the current environment. spam, .fam H \" helvetica family spam, \" used font is family H + style R = HR .ft B \" family H + style B = font HB spam, .fam T \" times family spam, \" used font is family T + style B = TB .ft AR \" font AR (not a style) baked beans, .ft R \" family T + style R = font TR and spam. Note that `\F' doesn't produce an input token in `gtroff'. As a consequence, it can be used in requests like `mc' (which expects a single character as an argument) to change the font family on the fly: .mc \F[P]x\F[] The `.fn' register contains the current "real font name" of the current font. This is a string-valued register. If the current font is a style, the value of `\n[.fn]' is the proper concatenation of family and style name. -- Request: .sty n style Associate STYLE with font position N. A font position can be associated either with a font or with a style. The current font is the index of a font position and so is also either a font or a style. If it is a style, the font that is actually used is the font which name is the concatenation of the name of the current family and the name of the current style. For example, if the current font is 1 and font position 1 is associated with style `R' and the current font family is `T', then font `TR' is used. If the current font is not a style, then the current family is ignored. If the requests `cs', `bd', `tkf', `uf', or `fspecial' are applied to a style, they are instead applied to the member of the current family corresponding to that style. N must be a non-negative integer value. The default family can be set with the `-f' option (*note Groff Options::). The `styles' command in the `DESC' file controls which font positions (if any) are initially associated with styles rather than fonts. For example, the default setting for POSTSCRIPT fonts styles R I B BI is equivalent to .sty 1 R .sty 2 I .sty 3 B .sty 4 BI `fam' and `\F' always check whether the current font position is valid; this can give surprising results if the current font position is associated with a style. In the following example, we want to access the POSTSCRIPT font `FooBar' from the font family `Foo': .sty \n[.fp] Bar .fam Foo => warning: can't find font `FooR' The default font position at start-up is 1; for the POSTSCRIPT device, this is associated with style `R', so `gtroff' tries to open `FooR'. A solution to this problem is to use a dummy font like the following: .fp 0 dummy TR \" set up dummy font at position 0 .sty \n[.fp] Bar \" register style `Bar' .ft 0 \" switch to font at position 0 .fam Foo \" activate family `Foo' .ft Bar \" switch to font `FooBar' *Note Font Positions::. 5.17.3 Font Positions --------------------- For the sake of old phototypesetters and compatibility with old versions of `troff', `gtroff' has the concept of font "positions", on which various fonts are mounted. -- Request: .fp pos font [external-name] -- Register: \n[.f] -- Register: \n[.fp] Mount font FONT at position POS (which must be a non-negative integer). This numeric position can then be referred to with font changing commands. When `gtroff' starts it is using font position 1 (which must exist; position 0 is unused usually at start-up). The current font in use, as a font position, is available in the read-only number register `.f'. This can be useful to remember the current font for later recall. It is associated with the current environment (*note Environments::). .nr save-font \n[.f] .ft B ... text text text ... .ft \n[save-font] The number of the next free font position is available in the read-only number register `.fp'. This is useful when mounting a new font, like so: .fp \n[.fp] NEATOFONT Fonts not listed in the `DESC' file are automatically mounted on the next available font position when they are referenced. If a font is to be mounted explicitly with the `fp' request on an unused font position, it should be mounted on the first unused font position, which can be found in the `.fp' register. Although `gtroff' does not enforce this strictly, it is not allowed to mount a font at a position whose number is much greater (approx. 1000 positions) than that of any currently used position. The `fp' request has an optional third argument. This argument gives the external name of the font, which is used for finding the font description file. The second argument gives the internal name of the font which is used to refer to the font in `gtroff' after it has been mounted. If there is no third argument then the internal name is used as the external name. This feature makes it possible to use fonts with long names in compatibility mode. Both the `ft' request and the `\f' escape have alternative syntax forms to access font positions. -- Request: .ft nnn -- Escape: \fn -- Escape: \f(nn -- Escape: \f[nnn] Change the current font position to NNN (one-digit position N, two-digit position NN), which must be a non-negative integer. If NNN is associated with a style (as set with the `sty' request or with the `styles' command in the `DESC' file), use it within the current font family (as set with the `fam' request, the `\F' escape, or with the `family' command in the `DESC' file). this is font 1 .ft 2 this is font 2 .ft \" switch back to font 1 .ft 3 this is font 3 .ft this is font 1 again *Note Changing Fonts::, for the standard syntax form. 5.17.4 Using Symbols -------------------- A "glyph" is a graphical representation of a "character". While a character is an abstract entity containing semantic information, a glyph is something which can be actually seen on screen or paper. It is possible that a character has multiple glyph representation forms (for example, the character `A' can be either written in a roman or an italic font, yielding two different glyphs); sometimes more than one character maps to a single glyph (this is a "ligature" - the most common is `fi'). A "symbol" is simply a named glyph. Within `gtroff', all glyph names of a particular font are defined in its font file. If the user requests a glyph not available in this font, `gtroff' looks up an ordered list of "special fonts". By default, the POSTSCRIPT output device supports the two special fonts `SS' (slanted symbols) and `S' (symbols) (the former is looked up before the latter). Other output devices use different names for special fonts. Fonts mounted with the `fonts' keyword in the `DESC' file are globally available. To install additional special fonts locally (i.e. for a particular font), use the `fspecial' request. Here the exact rules how `gtroff' searches a given symbol: * If the symbol has been defined with the `char' request, use it. This hides a symbol with the same name in the current font. * Check the current font. * If the symbol has been defined with the `fchar' request, use it. * Check whether the current font has a font-specific list of special fonts; test all fonts in the order of appearance in the last `fspecial' call if appropriate. * If the symbol has been defined with the `fschar' request for the current font, use it. * Check all fonts in the order of appearance in the last `special' call. * If the symbol has been defined with the `schar' request, use it. * As a last resort, consult all fonts loaded up to now for special fonts and check them, starting with the lowest font number. Note that this can sometimes lead to surprising results since the `fonts' line in the `DESC' file often contains empty positions which are filled later on. For example, consider the following: fonts 3 0 0 FOO This mounts font `foo' at font position 3. We assume that `FOO' is a special font, containing glyph `foo', and that no font has been loaded yet. The line .fspecial BAR BAZ makes font `BAZ' special only if font `BAR' is active. We further assume that `BAZ' is really a special font, i.e., the font description file contains the `special' keyword, and that it also contains glyph `foo' with a special shape fitting to font `BAR'. After executing `fspecial', font `BAR' is loaded at font position 1, and `BAZ' at position 2. We now switch to a new font `XXX', trying to access glyph `foo' which is assumed to be missing. There are neither font-specific special fonts for `XXX' nor any other fonts made special with the `special' request, so `gtroff' starts the search for special fonts in the list of already mounted fonts, with increasing font positions. Consequently, it finds `BAZ' before `FOO' even for `XXX' which is not the intended behaviour. *Note Font Files::, and *note Special Fonts::, for more details. The list of available symbols is device dependent; see the `groff_char(7)' man page for a complete list of all glyphs. For example, say man -Tdvi groff_char > groff_char.dvi for a list using the default DVI fonts (not all versions of the `man' program support the `-T' option). If you want to use an additional macro package to change the used fonts, `groff' must be called directly: groff -Tdvi -mec -man groff_char.7 > groff_char.dvi Glyph names not listed in groff_char(7) are derived algorithmically, using a simplified version of the Adobe Glyph List (AGL) algorithm which is described in `http://partners.adobe.com/public/developer/opentype/index_glyph.html'. The (frozen) set of glyph names which can't be derived algorithmically is called "groff glyph list (GGL)". * A glyph for Unicode character U+XXXX[X[X]] which is not a composite character is named `uXXXX[X[X]]'. X must be an uppercase hexadecimal digit. Examples: `u1234', `u008E', `u12DB8'. The largest Unicode value is 0x10FFFF. There must be at least four `X' digits; if necessary, add leading zeroes (after the `u'). No zero padding is allowed for character codes greater than 0xFFFF. Surrogates (i.e., Unicode values greater than 0xFFFF represented with character codes from the surrogate area U+D800-U+DFFF) are not allowed too. * A glyph representing more than a single input character is named `u' COMPONENT1 `_' COMPONENT2 `_' COMPONENT3 ... Example: `u0045_0302_0301'. For simplicity, all Unicode characters which are composites must be decomposed maximally (this is normalization form D in the Unicode standard); for example, `u00CA_0301' is not a valid glyph name since U+00CA (LATIN CAPITAL LETTER E WITH CIRCUMFLEX) can be further decomposed into U+0045 (LATIN CAPITAL LETTER E) and U+0302 (COMBINING CIRCUMFLEX ACCENT). `u0045_0302_0301' is thus the glyph name for U+1EBE, LATIN CAPITAL LETTER E WITH CIRCUMFLEX AND ACUTE. * groff maintains a table to decompose all algorithmically derived glyph names which are composites itself. For example, `u0100' (LATIN LETTER A WITH MACRON) is automatically decomposed into `u0041_0304'. Additionally, a glyph name of the GGL is preferred to an algorithmically derived glyph name; groff also automatically does the mapping. Example: The glyph `u0045_0302' is mapped to `^E'. * glyph names of the GGL can't be used in composite glyph names; for example, `^E_u0301' is invalid. -- Escape: \(nm -- Escape: \[name] -- Escape: \[component1 component2 ...] Insert a symbol NAME (two-character name NM) or a composite glyph with component glyphs COMPONENT1, COMPONENT2, ... There is no special syntax for one-character names - the natural form `\N' would collide with escapes.(1) (*note Using Symbols-Footnote-1::) If NAME is undefined, a warning of type `char' is generated, and the escape is ignored. *Note Debugging::, for information about warnings. groff resolves `\[...]' with more than a single component as follows: * Any component which is found in the GGL is converted to the `uXXXX' form. * Any component `uXXXX' which is found in the list of decomposable glyphs is decomposed. * The resulting elements are then concatenated with `_' in between, dropping the leading `u' in all elements but the first. No check for the existence of any component (similar to `tr' request) is done. Examples: `\[A ho]' `A' maps to `u0041', `ho' maps to `u02DB', thus the final glyph name would be `u0041_02DB'. Note this is not the expected result: The ogonek glyph `ho' is a spacing ogonek, but for a proper composite a non-spacing ogonek (U+0328) is necessary. Looking into the file `composite.tmac' one can find `.composite ho u0328' which changes the mapping of `ho' while a composite glyph name is constructed, causing the final glyph name to be `u0041_0328'. `\[^E u0301]' `\[^E aa]' `\[E a^ aa]' `\[E ^ ']' `^E' maps to `u0045_0302', thus the final glyph name is `u0045_0302_0301' in all forms (assuming proper calls of the `composite' request). It is not possible to define glyphs with names like `A ho' within a groff font file. This is not really a limitation; instead, you have to define `u0041_0328'. -- Escape: \C'xxx' Typeset the glyph named XXX.(2) (*note Using Symbols-Footnote-2::) Normally it is more convenient to use `\[XXX]', but `\C' has the advantage that it is compatible with newer versions of AT&T `troff' and is available in compatibility mode. -- Request: .composite from to Map glyph name FROM to glyph name TO if it is used in `\[...]' with more than one component. See above for examples. This mapping is based on glyph names only; no check for the existence of either glyph is done. A set of default mappings for many accents can be found in the file `composite.tmac' which is loaded at start-up. -- Escape: \N'n' Typeset the glyph with code N in the current font (`n' is *not* the input character code). The number N can be any non-negative decimal integer. Most devices only have glyphs with codes between 0 and 255; the Unicode output device uses codes in the range 0-65535. If the current font does not contain a glyph with that code, special fonts are _not_ searched. The `\N' escape sequence can be conveniently used in conjunction with the `char' request: .char \[phone] \f[ZD]\N'37' The code of each glyph is given in the fourth column in the font description file after the `charset' command. It is possible to include unnamed glyphs in the font description file by using a name of `---'; the `\N' escape sequence is the only way to use these. No kerning is applied to glyphs accessed with `\N'. Some escape sequences directly map onto special glyphs. -- Escape: \' This is a backslash followed by the apostrophe character, ASCII character `0x27' (EBCDIC character `0x7D'). The same as `\[aa]', the acute accent. -- Escape: \` This is a backslash followed by ASCII character `0x60' (EBCDIC character `0x79' usually). The same as `\[ga]', the grave accent. -- Escape: \- This is the same as `\[-]', the minus sign in the current font. -- Escape: \_ This is the same as `\[ul]', the underline character. -- Request: .cflags n c1 c2 ... Input characters and symbols have certain properties associated with it.(3) (*note Using Symbols-Footnote-3::) These properties can be modified with the `cflags' request. The first argument is the sum of the desired flags and the remaining arguments are the characters or symbols to have those properties. It is possible to omit the spaces between the characters or symbols. Instead of single characters or symbols you can also use character classes (see *note Character Classes:: for more details). `1' The character ends sentences (initially characters `.?!' have this property). `2' Lines can be broken before the character (initially no characters have this property). This only works if both the characters before and after have non-zero hyphenation codes (as set with the `hcode' request). Use value 64 to override this behaviour. `4' Lines can be broken after the character (initially the character `-' and the symbols `\[hy]' and `\[em]' have this property). This only works if both the characters before and after have non-zero hyphenation codes (as set with the `hcode' request). Use value 64 to override this behaviour. `8' The character overlaps horizontally if used as a horizontal line building element. Initially the symbols `\[ul]', `\[rn]', `\[ru]', `\[radicalex]', and `\[sqrtex]' have this property. `16' The character overlaps vertically if used as vertical line building element. Initially symbol `\[br]' has this property. `32' An end-of-sentence character followed by any number of characters with this property is treated as the end of a sentence if followed by a newline or two spaces; in other words the character is "transparent" for the purposes of end-of-sentence recognition - this is the same as having a zero space factor in TeX (initially characters `"')]*' and the symbols `\[dg]' and `\[rq]' have this property). `64' Ignore hyphenation code values of the surrounding characters. Use this in combination with values 2 and 4 (initially no characters have this property). For example, if you need an automatic break point after the hyphen in number ranges like `3000-5000', insert .cflags 68 - into your document. Note, however, that this can lead to bad layout if done without thinking; in most situations, a better solution instead of changing the `cflags' value is to insert `\:' right after the hyphen at the places which really need a break point. `128' Prohibit a line break before the character, but allow a line break after the character. This works only in combination with flags 256 and 512 (see below) and has no effect otherwise. `256' Prohibit a line break after the character, but allow a line break before the character. This works only in combination with flags 128 and 512 (see below) and has no effect otherwise. `512' Allow line break before or after the character. This works only in combination with flags 128 and 256 and has no effect otherwise. Contrary to flag values 2 and 4, the flags 128, 256, and 512 work pairwise. If, for example, the left character has value 512, and the right character 128, no line break gets inserted. If we use value 6 instead for the left character, a line break after the character can't be suppressed since the right neighbour character doesn't get examined. -- Request: .char g [string] -- Request: .fchar g [string] -- Request: .fschar f g [string] -- Request: .schar g [string] Define a new glyph G to be STRING (which can be empty).(4) (*note Using Symbols-Footnote-4::) Every time glyph G needs to be printed, STRING is processed in a temporary environment and the result is wrapped up into a single object. Compatibility mode is turned off and the escape character is set to `\' while STRING is being processed. Any emboldening, constant spacing or track kerning is applied to this object rather than to individual characters in STRING. A glyph defined by these requests can be used just like a normal glyph provided by the output device. In particular, other characters can be translated to it with the `tr' or `trin' requests; it can be made the leader character by the `lc' request; repeated patterns can be drawn with the glyph using the `\l' and `\L' escape sequences; words containing the glyph can be hyphenated correctly if the `hcode' request is used to give the glyph's symbol a hyphenation code. There is a special anti-recursion feature: Use of `g' within the glyph's definition is handled like normal characters and symbols not defined with `char'. Note that the `tr' and `trin' requests take precedence if `char' accesses the same symbol. .tr XY X => Y .char X Z X => Y .tr XX X => Z The `fchar' request defines a fallback glyph: `gtroff' only checks for glyphs defined with `fchar' if it cannot find the glyph in the current font. `gtroff' carries out this test before checking special fonts. `fschar' defines a fallback glyph for font F: `gtroff' checks for glyphs defined with `fschar' after the list of fonts declared as font-specific special fonts with the `fspecial' request, but before the list of fonts declared as global special fonts with the `special' request. Finally, the `schar' request defines a global fallback glyph: `gtroff' checks for glyphs defined with `schar' after the list of fonts declared as global special fonts with the `special' request, but before the already mounted special fonts. *Note Using Symbols::, for a detailed description of the glyph searching mechanism in `gtroff'. -- Request: .rchar c1 c2 ... -- Request: .rfschar f c1 c2 ... Remove the definitions of glyphs C1, C2, ... This undoes the effect of a `char', `fchar', or `schar' request. It is possible to omit the whitespace between arguments. The request `rfschar' removes glyph definitions defined with `fschar' for glyph f. *Note Special Characters::. (1) Note that a one-character symbol is not the same as an input character, i.e., the character `a' is not the same as `\[a]'. By default, `groff' defines only a single one-character symbol, `\[-]'; it is usually accessed as `\-'. On the other hand, `gtroff' has the special feature that `\[charXXX]' is the same as the input character with character code XXX. For example, `\[char97]' is identical to the letter `a' if ASCII encoding is active. (2) `\C' is actually a misnomer since it accesses an output glyph. (3) Note that the output glyphs themselves don't have such properties. For `gtroff', a glyph is a numbered box with a given width, depth, and height, nothing else. All manipulations with the `cflags' request work on the input level. (4) `char' is a misnomer since an output glyph is defined. 5.17.5 Character Classes ------------------------ Classes are particularly useful for East Asian languages such as Chinese, Japanese, and Korean, where the number of needed characters is much larger than in European languages, and where large sets of characters share the same properties. -- Request: .class n c1 c2 ... In `groff', a "character class" (or simply "class") is a set of characters, grouped by some user aspect. The `class' request defines such classes so that other requests can refer to all characters belonging to this set with a single class name. Currently, only the `cflags' request can handle character classes. A `class' request takes a class name followed by a list of entities. In its simplest form, the entities are characters or symbols: .class [prepunct] , : ; > } Since class and glyph names share the same namespace, it is recommended to start and end the class name with `[' and `]', respectively, to avoid collisions with normal `groff' symbols (and symbols defined by the user). In particular, the presence of `]' in the symbol name intentionally prevents the usage of `\[...]', thus you must use the `\C' escape to access a class with such a name. You can also use a special character range notation, consisting of a start character or symbol, followed by `-', and an end character or symbol. Internally, `gtroff' converts these two symbol names to Unicode values (according to the groff glyph gist) which then give the start and end value of the range. If that fails, the class definition is skipped. Finally, classes can be nested, too. Here is a more complex example: .class [prepunctx] \C'[prepunct]' \[u2013]-\[u2016] The class `prepunctx' now contains the contents of the class `prepunct' as defined above (the set `, : ; > }'), and characters in the range between `U+2013' and `U+2016'. If you want to add `-' to a class, it must be the first character value in the argument list, otherwise it gets misinterpreted as a range. Note that it is not possible to use class names within range definitions. Typical use of the `class' request is to control line-breaking and hyphenation rules as defined by the `cflags' request. For example, to inhibit line breaks before the characters belonging to the `prepunctx' class, you can write: .cflags 2 \C'[prepunctx]' See the `cflags' request in *note Using Symbols::, for more details. 5.17.6 Special Fonts -------------------- Special fonts are those that `gtroff' searches when it cannot find the requested glyph in the current font. The Symbol font is usually a special font. `gtroff' provides the following two requests to add more special fonts. *Note Using Symbols::, for a detailed description of the glyph searching mechanism in `gtroff'. Usually, only non-TTY devices have special fonts. -- Request: .special [s1 s2 ...] -- Request: .fspecial f [s1 s2 ...] Use the `special' request to define special fonts. Initially, this list is empty. Use the `fspecial' request to designate special fonts only when font F is active. Initially, this list is empty. Previous calls to `special' or `fspecial' are overwritten; without arguments, the particular list of special fonts is set to empty. Special fonts are searched in the order they appear as arguments. All fonts which appear in a call to `special' or `fspecial' are loaded. *Note Using Symbols::, for the exact search order of glyphs. 5.17.7 Artificial Fonts ----------------------- There are a number of requests and escapes for artificially creating fonts. These are largely vestiges of the days when output devices did not have a wide variety of fonts, and when `nroff' and `troff' were separate programs. Most of them are no longer necessary in GNU `troff'. Nevertheless, they are supported. -- Escape: \H'height' -- Escape: \H'+height' -- Escape: \H'-height' -- Register: \n[.height] Change (increment, decrement) the height of the current font, but not the width. If HEIGHT is zero, restore the original height. Default scaling indicator is `z'. The read-only number register `.height' contains the font height as set by `\H'. Currently, only the `-Tps' and `-Tpdf' devices support this feature. Note that `\H' doesn't produce an input token in `gtroff'. As a consequence, it can be used in requests like `mc' (which expects a single character as an argument) to change the font on the fly: .mc \H'+5z'x\H'0' In compatibility mode, `gtroff' behaves differently: If an increment or decrement is used, it is always taken relative to the current point size and not relative to the previously selected font height. Thus, .cp 1 \H'+5'test \H'+5'test prints the word `test' twice with the same font height (five points larger than the current font size). -- Escape: \S'slant' -- Register: \n[.slant] Slant the current font by SLANT degrees. Positive values slant to the right. Only integer values are possible. The read-only number register `.slant' contains the font slant as set by `\S'. Currently, only the `-Tps' and `-Tpdf' devices support this feature. Note that `\S' doesn't produce an input token in `gtroff'. As a consequence, it can be used in requests like `mc' (which expects a single character as an argument) to change the font on the fly: .mc \S'20'x\S'0' This request is incorrectly documented in the original UNIX troff manual; the slant is always set to an absolute value. -- Request: .ul [lines] The `ul' request normally underlines subsequent lines if a TTY output device is used. Otherwise, the lines are printed in italics (only the term `underlined' is used in the following). The single argument is the number of input lines to be underlined; with no argument, the next line is underlined. If LINES is zero or negative, stop the effects of `ul' (if it was active). Requests and empty lines do not count for computing the number of underlined input lines, even if they produce some output like `tl'. Lines inserted by macros (e.g. invoked by a trap) do count. At the beginning of `ul', the current font is stored and the underline font is activated. Within the span of a `ul' request, it is possible to change fonts, but after the last line affected by `ul' the saved font is restored. This number of lines still to be underlined is associated with the current environment (*note Environments::). The underline font can be changed with the `uf' request. The `ul' request does not underline spaces. -- Request: .cu [lines] The `cu' request is similar to `ul' but underlines spaces as well (if a TTY output device is used). -- Request: .uf font Set the underline font (globally) used by `ul' and `cu'. By default, this is the font at position 2. FONT can be either a non-negative font position or the name of a font. -- Request: .bd font [offset] -- Request: .bd font1 font2 [offset] -- Register: \n[.b] Artificially create a bold font by printing each glyph twice, slightly offset. Two syntax forms are available. * Imitate a bold font unconditionally. The first argument specifies the font to embolden, and the second is the number of basic units, minus one, by which the two glyphs are offset. If the second argument is missing, emboldening is turned off. FONT can be either a non-negative font position or the name of a font. OFFSET is available in the `.b' read-only register if a special font is active; in the `bd' request, its default unit is `u'. * Imitate a bold form conditionally. Embolden FONT1 by OFFSET only if font FONT2 is the current font. This command can be issued repeatedly to set up different emboldening values for different current fonts. If the second argument is missing, emboldening is turned off for this particular current font. This affects special fonts only (either set up with the `special' command in font files or with the `fspecial' request). -- Request: .cs font [width [em-size]] Switch to and from "constant glyph space mode". If activated, the width of every glyph is WIDTH/36 ems. The em size is given absolutely by EM-SIZE; if this argument is missing, the em value is taken from the current font size (as set with the `ps' request) when the font is effectively in use. Without second and third argument, constant glyph space mode is deactivated. Default scaling indicator for EM-SIZE is `z'; WIDTH is an integer. 5.17.8 Ligatures and Kerning ---------------------------- Ligatures are groups of characters that are run together, i.e, producing a single glyph. For example, the letters `f' and `i' can form a ligature `fi' as in the word `file'. This produces a cleaner look (albeit subtle) to the printed output. Usually, ligatures are not available in fonts for TTY output devices. Most POSTSCRIPT fonts support the fi and fl ligatures. The C/A/T typesetter that was the target of AT&T `troff' also supported `ff', `ffi', and `ffl' ligatures. Advanced typesetters or `expert' fonts may include ligatures for `ft' and `ct', although GNU `troff' does not support these (yet). Only the current font is checked for ligatures and kerns; neither special fonts nor entities defined with the `char' request (and its siblings) are taken into account. -- Request: .lg [flag] -- Register: \n[.lg] Switch the ligature mechanism on or off; if the parameter is non-zero or missing, ligatures are enabled, otherwise disabled. Default is on. The current ligature mode can be found in the read-only number register `.lg' (set to 1 or 2 if ligatures are enabled, 0 otherwise). Setting the ligature mode to 2 enables the two-character ligatures (fi, fl, and ff) and disables the three-character ligatures (ffi and ffl). "Pairwise kerning" is another subtle typesetting mechanism that modifies the distance between a glyph pair to improve readability. In most cases (but not always) the distance is decreased. Typewriter-like fonts and fonts for terminals where all glyphs have the same width don't use kerning. -- Request: .kern [flag] -- Register: \n[.kern] Switch kerning on or off. If the parameter is non-zero or missing, enable pairwise kerning, otherwise disable it. The read-only number register `.kern' is set to 1 if pairwise kerning is enabled, 0 otherwise. If the font description file contains pairwise kerning information, glyphs from that font are kerned. Kerning between two glyphs can be inhibited by placing `\&' between them: `V\&A'. *Note Font File Format::. "Track kerning" expands or reduces the space between glyphs. This can be handy, for example, if you need to squeeze a long word onto a single line or spread some text to fill a narrow column. It must be used with great care since it is usually considered bad typography if the reader notices the effect. -- Request: .tkf f s1 n1 s2 n2 Enable track kerning for font F. If the current font is F the width of every glyph is increased by an amount between N1 and N2 (N1, N2 can be negative); if the current point size is less than or equal to S1 the width is increased by N1; if it is greater than or equal to S2 the width is increased by N2; if the point size is greater than or equal to S1 and less than or equal to S2 the increase in width is a linear function of the point size. The default scaling indicator is `z' for S1 and S2, `p' for N1 and N2. Note that the track kerning amount is added even to the rightmost glyph in a line; for large values it is thus recommended to increase the line length by the same amount to compensate it. Sometimes, when typesetting letters of different fonts, more or less space at such boundaries are needed. There are two escapes to help with this. -- Escape: \/ Increase the width of the preceding glyph so that the spacing between that glyph and the following glyph is correct if the following glyph is a roman glyph. For example, if an italic `f' is immediately followed by a roman right parenthesis, then in many fonts the top right portion of the `f' overlaps the top left of the right parenthesis. Use this escape sequence whenever an italic glyph is immediately followed by a roman glyph without any intervening space. This small amount of space is also called "italic correction". -- Escape: \, Modify the spacing of the following glyph so that the spacing between that glyph and the preceding glyph is correct if the preceding glyph is a roman glyph. Use this escape sequence whenever a roman glyph is immediately followed by an italic glyph without any intervening space. In analogy to above, this space could be called "left italic correction", but this term isn't used widely. -- Escape: \& Insert a zero-width character, which is invisible. Its intended use is to stop interaction of a character with its surrounding. * It prevents the insertion of extra space after an end-of-sentence character. Test. Test. => Test. Test. Test.\& Test. => Test. Test. * It prevents interpretation of a control character at the beginning of an input line. .Test => warning: `Test' not defined \&.Test => .Test * It prevents kerning between two glyphs. * It is needed to map an arbitrary character to nothing in the `tr' request (*note Character Translations::). -- Escape: \) This escape is similar to `\&' except that it behaves like a character declared with the `cflags' request to be transparent for the purposes of an end-of-sentence character. Its main usage is in macro definitions to protect against arguments starting with a control character. .de xxx \)\\$1 .. .de yyy \&\\$1 .. This is a test.\c .xxx ' This is a test. =>This is a test.' This is a test. This is a test.\c .yyy ' This is a test. =>This is a test.' This is a test. 5.18 Sizes ========== `gtroff' uses two dimensions with each line of text, type size and vertical spacing. The "type size" is approximately the height of the tallest glyph.(1) (*note Sizes-Footnote-1::) "Vertical spacing" is the amount of space `gtroff' allows for a line of text; normally, this is about 20% larger than the current type size. Ratios smaller than this can result in hard-to-read text; larger than this, it spreads the text out more vertically (useful for term papers). By default, `gtroff' uses 10 point type on 12 point spacing. The difference between type size and vertical spacing is known, by typesetters, as "leading" (this is pronounced `ledding'). (1) This is usually the parenthesis. Note that in most cases the real dimensions of the glyphs in a font are _not_ related to its type size! For example, the standard POSTSCRIPT font families `Times Roman', `Helvetica', and `Courier' can't be used together at 10pt; to get acceptable output, the size of `Helvetica' has to be reduced by one point, and the size of `Courier' must be increased by one point. 5.18.1 Changing Type Sizes -------------------------- -- Request: .ps [size] -- Request: .ps +size -- Request: .ps -size -- Escape: \ssize -- Register: \n[.s] Use the `ps' request or the `\s' escape to change (increase, decrease) the type size (in points). Specify SIZE as either an absolute point size, or as a relative change from the current size. The size 0, or no argument, goes back to the previous size. Default scaling indicator of `size' is `z'. If `size' is zero or negative, it is set to 1u. The read-only number register `.s' returns the point size in points as a decimal fraction. This is a string. To get the point size in scaled points, use the `.ps' register instead. `.s' is associated with the current environment (*note Environments::). snap, snap, .ps +2 grin, grin, .ps +2 wink, wink, \s+2nudge, nudge,\s+8 say no more! .ps 10 The `\s' escape may be called in a variety of ways. Much like other escapes there must be a way to determine where the argument ends and the text begins. Any of the following forms are valid: `\sN' Set the point size to N points. N must be either 0 or in the range 4 to 39. `\s+N' `\s-N' Increase or decrease the point size by N points. N must be exactly one digit. `\s(NN' Set the point size to NN points. NN must be exactly two digits. `\s+(NN' `\s-(NN' `\s(+NN' `\s(-NN' Increase or decrease the point size by NN points. NN must be exactly two digits. Note that `\s' doesn't produce an input token in `gtroff'. As a consequence, it can be used in requests like `mc' (which expects a single character as an argument) to change the font on the fly: .mc \s[20]x\s[0] *Note Fractional Type Sizes::, for yet another syntactical form of using the `\s' escape. -- Request: .sizes s1 s2 ... sn [0] Some devices may only have certain permissible sizes, in which case `gtroff' rounds to the nearest permissible size. The `DESC' file specifies which sizes are permissible for the device. Use the `sizes' request to change the permissible sizes for the current output device. Arguments are in scaled points; the `sizescale' line in the `DESC' file for the output device provides the scaling factor. For example, if the scaling factor is 1000, then the value 12000 is 12 points. Each argument can be a single point size (such as `12000'), or a range of sizes (such as `4000-72000'). You can optionally end the list with a zero. -- Request: .vs [space] -- Request: .vs +space -- Request: .vs -space -- Register: \n[.v] Change (increase, decrease) the vertical spacing by SPACE. The default scaling indicator is `p'. If `vs' is called without an argument, the vertical spacing is reset to the previous value before the last call to `vs'. `gtroff' creates a warning of type `range' if SPACE is negative; the vertical spacing is then set to smallest positive value, the vertical resolution (as given in the `.V' register). Note that `.vs 0' isn't saved in a diversion since it doesn't result in a vertical motion. You explicitly have to repeat this command before inserting the diversion. The read-only number register `.v' contains the current vertical spacing; it is associated with the current environment (*note Environments::). The effective vertical line spacing consists of four components. Breaking a line causes the following actions (in the given order). * Move the current point vertically by the "extra pre-vertical line space". This is the minimum value of all `\x' escapes with a negative argument in the current output line. * Move the current point vertically by the vertical line spacing as set with the `vs' request. * Output the current line. * Move the current point vertically by the "extra post-vertical line space". This is the maximum value of all `\x' escapes with a positive argument in the line which has just been output. * Move the current point vertically by the "post-vertical line spacing" as set with the `pvs' request. It is usually better to use `vs' or `pvs' instead of `ls' to produce double-spaced documents: `vs' and `pvs' have a finer granularity for the inserted vertical space compared to `ls'; furthermore, certain preprocessors assume single-spacing. *Note Manipulating Spacing::, for more details on the `\x' escape and the `ls' request. -- Request: .pvs [space] -- Request: .pvs +space -- Request: .pvs -space -- Register: \n[.pvs] Change (increase, decrease) the post-vertical spacing by SPACE. The default scaling indicator is `p'. If `pvs' is called without an argument, the post-vertical spacing is reset to the previous value before the last call to `pvs'. `gtroff' creates a warning of type `range' if SPACE is zero or negative; the vertical spacing is then set to zero. The read-only number register `.pvs' contains the current post-vertical spacing; it is associated with the current environment (*note Environments::). 5.18.2 Fractional Type Sizes ---------------------------- A "scaled point" is equal to 1/SIZESCALE points, where SIZESCALE is specified in the `DESC' file (1 by default). There is a new scale indicator `z' which has the effect of multiplying by SIZESCALE. Requests and escape sequences in `gtroff' interpret arguments that represent a point size as being in units of scaled points, but they evaluate each such argument using a default scale indicator of `z'. Arguments treated in this way are the argument to the `ps' request, the third argument to the `cs' request, the second and fourth arguments to the `tkf' request, the argument to the `\H' escape sequence, and those variants of the `\s' escape sequence that take a numeric expression as their argument (see below). For example, suppose SIZESCALE is 1000; then a scaled point is equivalent to a millipoint; the request `.ps 10.25' is equivalent to `.ps 10.25z' and thus sets the point size to 10250 scaled points, which is equal to 10.25 points. `gtroff' disallows the use of the `z' scale indicator in instances where it would make no sense, such as a numeric expression whose default scale indicator was neither `u' nor `z'. Similarly it would make no sense to use a scaling indicator other than `z' or `u' in a numeric expression whose default scale indicator was `z', and so `gtroff' disallows this as well. There is also new scale indicator `s' which multiplies by the number of units in a scaled point. So, for example, `\n[.ps]s' is equal to `1m'. Be sure not to confuse the `s' and `z' scale indicators. -- Register: \n[.ps] A read-only number register returning the point size in scaled points. `.ps' is associated with the current environment (*note Environments::). -- Register: \n[.psr] -- Register: \n[.sr] The last-requested point size in scaled points is contained in the `.psr' read-only number register. The last requested point size in points as a decimal fraction can be found in `.sr'. This is a string-valued read-only number register. Note that the requested point sizes are device-independent, whereas the values returned by the `.ps' and `.s' registers are not. For example, if a point size of 11pt is requested, and a `sizes' request (or a `sizescale' line in a `DESC' file) specifies 10.95pt instead, this value is actually used. Both registers are associated with the current environment (*note Environments::). The `\s' escape has the following syntax for working with fractional type sizes: `\s[N]' `\s'N'' Set the point size to N scaled points; N is a numeric expression with a default scale indicator of `z'. `\s[+N]' `\s[-N]' `\s+[N]' `\s-[N]' `\s'+N'' `\s'-N'' `\s+'N'' `\s-'N'' Increase or or decrease the point size by N scaled points; N is a numeric expression (which may start with a minus sign) with a default scale indicator of `z'. *Note Font Files::. 5.19 Strings ============ `gtroff' has string variables, which are entirely for user convenience (i.e. there are no built-in strings exept `.T', but even this is a read-write string variable). Although the following requests can be used to create strings, simply using an undefined string will cause it to be defined as empty. *Note Identifiers::. -- Request: .ds name [string] -- Request: .ds1 name [string] -- Escape: \*n -- Escape: \*(nm -- Escape: \*[name arg1 arg2 ...] Define and access a string variable NAME (one-character name N, two-character name NM). If NAME already exists, `ds' overwrites the previous definition. Only the syntax form using brackets can take arguments which are handled identically to macro arguments; the single exception is that a closing bracket as an argument must be enclosed in double quotes. *Note Request and Macro Arguments::, and *note Parameters::. Example: .ds foo a \\$1 test . This is \*[foo nice]. => This is a nice test. The `\*' escape "interpolates" (expands in-place) a previously-defined string variable. To be more precise, the stored string is pushed onto the input stack which is then parsed by `gtroff'. Similar to number registers, it is possible to nest strings, i.e., string variables can be called within string variables. If the string named by the `\*' escape does not exist, it is defined as empty, and a warning of type `mac' is emitted (see *note Debugging::, for more details). *Caution:* Unlike other requests, the second argument to the `ds' request takes up the entire line including trailing spaces. This means that comments on a line with such a request can introduce unwanted space into a string. .ds UX \s-1UNIX\s0\u\s-3tm\s0\d \" UNIX trademark Instead the comment should be put on another line or have the comment escape adjacent with the end of the string. .ds UX \s-1UNIX\s0\u\s-3tm\s0\d\" UNIX trademark To produce leading space the string can be started with a double quote. No trailing quote is needed; in fact, any trailing quote is included in your string. .ds sign " Yours in a white wine sauce, Strings are not limited to a single line of text. A string can span several lines by escaping the newlines with a backslash. The resulting string is stored _without_ the newlines. .ds foo lots and lots \ of text are on these \ next several lines It is not possible to have real newlines in a string. To put a single double quote character into a string, use two consecutive double quote characters. The `ds1' request turns off compatibility mode while interpreting a string. To be more precise, a "compatibility save" input token is inserted at the beginning of the string, and a "compatibility restore" input token at the end. .nr xxx 12345 .ds aa The value of xxx is \\n[xxx]. .ds1 bb The value of xxx ix \\n[xxx]. . .cp 1 . \*(aa => warning: number register `[' not defined => The value of xxx is 0xxx]. \*(bb => The value of xxx ix 12345. Strings, macros, and diversions (and boxes) share the same name space. Internally, even the same mechanism is used to store them. This has some interesting consequences. For example, it is possible to call a macro with string syntax and vice versa. .de xxx a funny test. .. This is \*[xxx] => This is a funny test. .ds yyy a funny test This is .yyy => This is a funny test. In particular, interpolating a string does not hide existing macro arguments. Thus in a macro, a more efficient way of doing .xx \\$@ is \\*[xx]\\ Note that the latter calling syntax doesn't change the value of `\$0', which is then inherited from the calling macro. Diversions and boxes can be also called with string syntax. Another consequence is that you can copy one-line diversions or boxes to a string. .di xxx a \fItest\fR .br .di .ds yyy This is \*[xxx]\c \*[yyy]. => This is a test. As the previous example shows, it is possible to store formatted output in strings. The `\c' escape prevents the insertion of an additional blank line in the output. Copying diversions longer than a single output line produces unexpected results. .di xxx a funny .br test .br .di .ds yyy This is \*[xxx]\c \*[yyy]. => test This is a funny. Usually, it is not predictable whether a diversion contains one or more output lines, so this mechanism should be avoided. With UNIX `troff', this was the only solution to strip off a final newline from a diversion. Another disadvantage is that the spaces in the copied string are already formatted, making them unstretchable. This can cause ugly results. A clean solution to this problem is available in GNU `troff', using the requests `chop' to remove the final newline of a diversion, and `unformat' to make the horizontal spaces stretchable again. .box xxx a funny .br test .br .box .chop xxx .unformat xxx This is \*[xxx]. => This is a funny test. *Note Gtroff Internals::, for more information. -- Request: .as name [string] -- Request: .as1 name [string] The `as' request is similar to `ds' but appends STRING to the string stored as NAME instead of redefining it. If NAME doesn't exist yet, it is created. .as sign " with shallots, onions and garlic, The `as1' request is similar to `as', but compatibility mode is switched off while the appended string is interpreted. To be more precise, a "compatibility save" input token is inserted at the beginning of the appended string, and a "compatibility restore" input token at the end. Rudimentary string manipulation routines are given with the next two requests. -- Request: .substring str n1 [n2] Replace the string named STR with the substring defined by the indices N1 and N2. The first character in the string has index 0. If N2 is omitted, it is taken to be equal to the string's length. If the index value N1 or N2 is negative, it is counted from the end of the string, going backwards: The last character has index -1, the character before the last character has index -2, etc. .ds xxx abcdefgh .substring xxx 1 -4 \*[xxx] => bcde -- Request: .length reg str Compute the number of characters of STR and return it in the number register REG. If REG doesn't exist, it is created. `str' is read in copy mode. .ds xxx abcd\h'3i'efgh .length yyy \*[xxx] \n[yyy] => 14 -- Request: .rn xx yy Rename the request, macro, diversion, or string XX to YY. -- Request: .rm xx Remove the request, macro, diversion, or string XX. `gtroff' treats subsequent invocations as if the object had never been defined. -- Request: .als new old Create an alias named NEW for the request, string, macro, or diversion object named OLD. The new name and the old name are exactly equivalent (it is similar to a hard rather than a soft link). If OLD is undefined, `gtroff' generates a warning of type `mac' and ignores the request. To understand how the `als' request works it is probably best to think of two different pools: one pool for objects (macros, strings, etc.), and another one for names. As soon as an object is defined, `gtroff' adds it to the object pool, adds its name to the name pool, and creates a link between them. When `als' creates an alias, it adds a new name to the name pool which gets linked to the same object as the old name. Now consider this example. .de foo .. . .als bar foo . .de bar . foo .. . .bar => input stack limit exceeded The definition of macro `bar' replaces the old object this name is linked to. However, the alias to `foo' is still active! In other words, `foo' is still linked to the same object as `bar', and the result of calling `bar' is an infinite, recursive loop which finally leads to an error. To undo an alias, simply call `rm' on the aliased name. The object itself is not destroyed until there are no more aliases. -- Request: .chop xx Remove (chop) the last character from the macro, string, or diversion named XX. This is useful for removing the newline from the end of diversions that are to be interpolated as strings. This command can be used repeatedly; see *note Gtroff Internals::, for details on nodes inserted additionally by `gtroff'. *Note Identifiers::, and *note Comments::. 5.20 Conditionals and Loops =========================== 5.20.1 Operators in Conditionals -------------------------------- In `if', `ie', and `while' requests, in addition to ordinary *note Expressions::, there are several more operators available: `e' `o' True if the current page is even or odd numbered (respectively). `n' True if the document is being processed in nroff mode (i.e., the `.nroff' command has been issued). *Note Troff and Nroff Mode::. `t' True if the document is being processed in troff mode (i.e., the `.troff' command has been issued). *Note Troff and Nroff Mode::. `v' Always false. This condition is for compatibility with other `troff' versions only (identifying a `-Tversatec' device). `'XXX'YYY'' True if the output produced by XXX is equal to the output produced by YYY. Other characters can be used in place of the single quotes; the same set of delimiters as for the `\D' escape is used (*note Escapes::). `gtroff' formats XXX and YYY in separate environments; after the comparison the resulting data is discarded. .ie "|"\fR|\fP" \ true .el \ false => true The resulting motions, glyph sizes, and fonts have to match,(1) (*note Operators in Conditionals-Footnote-1::) and not the individual motion, size, and font requests. In the previous example, `|' and `\fR|\fP' both result in a roman `|' glyph with the same point size and at the same location on the page, so the strings are equal. If `.ft I' had been added before the `.ie', the result would be "false" because (the first) `|' produces an italic `|' rather than a roman one. To compare strings without processing, surround the data with `\?'. .ie "\?|\?"\?\fR|\fP\?" \ true .el \ false => false Since data protected with `\?' is read in copy-in mode it is even possible to use incomplete input without causing an error. .ds a \[ .ds b \[ .ie '\?\*a\?'\?\*b\?' \ true .el \ false => true `r XXX' True if there is a number register named XXX. `d XXX' True if there is a string, macro, diversion, or request named XXX. `m XXX' True if there is a color named XXX. `c G' True if there is a glyph G available(2) (*note Operators in Conditionals-Footnote-2::); G is either an ASCII character or a special character (`\N'XXX'', `\(GG' or `\[GGG]'); the condition is also true if G has been defined by the `char' request. `F FONT' True if a font named FONT exists. FONT is handled as if it was opened with the `ft' request (this is, font translation and styles are applied), without actually mounting it. This test doesn't load the complete font but only its header to verify its validity. `S STYLE' True if style STYLE has been registered. Font translation is applied. Note that these operators can't be combined with other operators like `:' or `&'; only a leading `!' (without whitespace between the exclamation mark and the operator) can be used to negate the result. .nr xxx 1 .ie !r xxx \ true .el \ false => false A whitespace after `!' always evaluates to zero (this bizarre behaviour is due to compatibility with UNIX `troff'). .nr xxx 1 .ie ! r xxx \ true .el \ false => r xxx true It is possible to omit the whitespace before the argument to the `r', `d', and `c' operators. *Note Expressions::. (1) The created output nodes must be identical. *Note Gtroff Internals::. (2) The name of this conditional operator is a misnomer since it tests names of output glyphs. 5.20.2 if-else -------------- `gtroff' has if-then-else constructs like other languages, although the formatting can be painful. -- Request: .if expr anything Evaluate the expression EXPR, and executes ANYTHING (the remainder of the line) if EXPR evaluates to a value greater than zero (true). ANYTHING is interpreted as though it was on a line by itself (except that leading spaces are swallowed). *Note Operators in Conditionals::, for more info. .nr xxx 1 .nr yyy 2 .if ((\n[xxx] == 1) & (\n[yyy] == 2)) true => true -- Request: .nop anything Executes ANYTHING. This is similar to `.if 1'. -- Request: .ie expr anything -- Request: .el anything Use the `ie' and `el' requests to write an if-then-else. The first request is the `if' part and the latter is the `else' part. .ie n .ls 2 \" double-spacing in nroff .el .ls 1 \" single-spacing in troff -- Escape: \{ -- Escape: \} In many cases, an if (or if-else) construct needs to execute more than one request. This can be done using the `\{' and `\}' escapes. The following example shows the possible ways to use these escapes (note the position of the opening and closing braces). .ie t \{\ . ds lq `` . ds rq '' .\} .el \ .\{\ . ds lq " . ds rq "\} *Note Expressions::. 5.20.3 while ------------ `gtroff' provides a looping construct using the `while' request, which is used much like the `if' (and related) requests. -- Request: .while expr anything Evaluate the expression EXPR, and repeatedly execute ANYTHING (the remainder of the line) until EXPR evaluates to 0. .nr a 0 1 .while (\na < 9) \{\ \n+a, .\} \n+a => 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 Some remarks. * The body of a `while' request is treated like the body of a `de' request: `gtroff' temporarily stores it in a macro which is deleted after the loop has been exited. It can considerably slow down a macro if the body of the `while' request (within the macro) is large. Each time the macro is executed, the `while' body is parsed and stored again as a temporary macro. .de xxx . nr num 10 . while (\\n[num] > 0) \{\ . \" many lines of code . nr num -1 . \} .. The traditional and ofter better solution (UNIX `troff' doesn't have the `while' request) is to use a recursive macro instead which is parsed only once during its definition. .de yyy . if (\\n[num] > 0) \{\ . \" many lines of code . nr num -1 . yyy . \} .. . .de xxx . nr num 10 . yyy .. Note that the number of available recursion levels is set to 1000 (this is a compile-time constant value of `gtroff'). * The closing brace of a `while' body must end a line. .if 1 \{\ . nr a 0 1 . while (\n[a] < 10) \{\ . nop \n+[a] .\}\} => unbalanced \{ \} -- Request: .break Break out of a `while' loop. Be sure not to confuse this with the `br' request (causing a line break). -- Request: .continue Finish the current iteration of a `while' loop, immediately restarting the next iteration. *Note Expressions::. 5.21 Writing Macros =================== A "macro" is a collection of text and embedded commands which can be invoked multiple times. Use macros to define common operations. *Note Strings::, for a (limited) alternative syntax to call macros. Although the following requests can be used to create macros, simply using an undefined macro will cause it to be defined as empty. *Note Identifiers::. -- Request: .de name [end] -- Request: .de1 name [end] -- Request: .dei name [end] -- Request: .dei1 name [end] Define a new macro named NAME. `gtroff' copies subsequent lines (starting with the next one) into an internal buffer until it encounters the line `..' (two dots). If the optional second argument to `de' is present it is used as the macro closure request instead of `..'. There can be whitespace after the first dot in the line containing the ending token (either `.' or macro `END'). Don't insert a tab character immediately after the `..', otherwise it isn't recognized as the end-of-macro symbol.(1) (*note Writing Macros-Footnote-1::) Here a small example macro called `P' which causes a break and inserts some vertical space. It could be used to separate paragraphs. .de P . br . sp .8v .. The following example defines a macro within another. Remember that expansion must be protected twice; once for reading the macro and once for executing. \# a dummy macro to avoid a warning .de end .. . .de foo . de bar end . nop \f[B]Hallo \\\\$1!\f[] . end .. . .foo .bar Joe => Hallo Joe! Since `\f' has no expansion, it isn't necessary to protect its backslash. Had we defined another macro within `bar' which takes a parameter, eight backslashes would be necessary before `$1'. The `de1' request turns off compatibility mode while executing the macro. On entry, the current compatibility mode is saved and restored at exit. .nr xxx 12345 . .de aa The value of xxx is \\n[xxx]. .. .de1 bb The value of xxx ix \\n[xxx]. .. . .cp 1 . .aa => warning: number register `[' not defined => The value of xxx is 0xxx]. .bb => The value of xxx ix 12345. The `dei' request defines a macro indirectly. That is, it expands strings whose names are NAME or END before performing the append. This: .ds xx aa .ds yy bb .dei xx yy is equivalent to: .de aa bb The `dei1' request is similar to `dei' but with compatibility mode switched off during execution of the defined macro. If compatibility mode is on, `de' (and `dei') behave similar to `de1' (and `dei1'): A `compatibility save' token is inserted at the beginning, and a `compatibility restore' token at the end, with compatibility mode switched on during execution. *Note Gtroff Internals::, for more information on switching compatibility mode on and off in a single document. Using `trace.tmac', you can trace calls to `de' and `de1'. Note that macro identifiers are shared with identifiers for strings and diversions. *Note the description of the `als' request: als, for possible pitfalls if redefining a macro which has been aliased. -- Request: .am name [end] -- Request: .am1 name [end] -- Request: .ami name [end] -- Request: .ami1 name [end] Works similarly to `de' except it appends onto the macro named NAME. So, to make the previously defined `P' macro actually do indented instead of block paragraphs, add the necessary code to the existing macro like this: .am P .ti +5n .. The `am1' request turns off compatibility mode while executing the appended macro piece. To be more precise, a "compatibility save" input token is inserted at the beginning of the appended code, and a "compatibility restore" input token at the end. The `ami' request appends indirectly, meaning that `gtroff' expands strings whose names are NAME or END before performing the append. The `ami1' request is similar to `ami' but compatibility mode is switched off during execution of the defined macro. Using `trace.tmac', you can trace calls to `am' and `am1'. *Note Strings::, for the `als' and `rn' request to create an alias and rename a macro, respectively. The `de', `am', `di', `da', `ds', and `as' requests (together with its variants) only create a new object if the name of the macro, diversion or string diversion is currently undefined or if it is defined to be a request; normally they modify the value of an existing object. -- Request: .return [anything] Exit a macro, immediately returning to the caller. If called with an argument, exit twice, namely the current macro and the macro one level higher. This is used to define a wrapper macro for `return' in `trace.tmac'. (1) While it is possible to define and call a macro `.' with .de . . tm foo .. . .. \" This calls macro `.'! you can't use this as the end-of-macro macro: during a macro definition, `..' is never handled as a call to `.', even if you say `.de foo .' explicitly. 5.21.1 Copy-in Mode ------------------- When `gtroff' reads in the text for a macro, string, or diversion, it copies the text (including request lines, but excluding escapes) into an internal buffer. Escapes are converted into an internal form, except for `\n', `\$', `\*', `\\' and `\' which are evaluated and inserted into the text where the escape was located. This is known as "copy-in" mode or "copy" mode. What this means is that you can specify when these escapes are to be evaluated (either at copy-in time or at the time of use) by insulating the escapes with an extra backslash. Compare this to the `\def' and `\edef' commands in TeX. The following example prints the numbers 20 and 10: .nr x 20 .de y .nr x 10 \&\nx \&\\nx .. .y 5.21.2 Parameters ----------------- The arguments to a macro or string can be examined using a variety of escapes. -- Register: \n[.$] The number of arguments passed to a macro or string. This is a read-only number register. Note that the `shift' request can change its value. Any individual argument can be retrieved with one of the following escapes: -- Escape: \$n -- Escape: \$(nn -- Escape: \$[nnn] Retrieve the Nth, NNth or NNNth argument. As usual, the first form only accepts a single number (larger than zero), the second a two-digit number (larger or equal to 10), and the third any positive integer value (larger than zero). Macros and strings can have an unlimited number of arguments. Note that due to copy-in mode, use two backslashes on these in actual use to prevent interpolation until the macro is actually invoked. -- Request: .shift [n] Shift the arguments 1 position, or as many positions as specified by its argument. After executing this request, argument I becomes argument I-N; arguments 1 to N are no longer available. Shifting by negative amounts is currently undefined. The register `.$' is adjusted accordingly. -- Escape: \$* -- Escape: \$@ In some cases it is convenient to use all of the arguments at once (for example, to pass the arguments along to another macro). The `\$*' escape concatenates all the arguments separated by spaces. A similar escape is `\$@', which concatenates all the arguments with each surrounded by double quotes, and separated by spaces. If not in compatibility mode, the input level of double quotes is preserved (see *note Request and Macro Arguments::). -- Escape: \$^ Handle the parameters of a macro as if they were an argument to the `ds' or similar requests. .de foo . tm $1=`\\$1' . tm $2=`\\$2' . tm $*=`\\$*' . tm $@=`\\$@' . tm $^=`\\$^' .. .foo " This is a "test" => $1=` This is a ' => $2=`test"' => $*=` This is a test"' => $@=`" This is a " "test""' => $^=`" This is a "test"' This escape is useful mainly for macro packages like `trace.tmac' which redefines some requests and macros for debugging purposes. -- Escape: \$0 The name used to invoke the current macro. The `als' request can make a macro have more than one name. If a macro is called as a string (within another macro), the value of `\$0' isn't changed. .de foo . tm \\$0 .. .als foo bar . .de aaa . foo .. .de bbb . bar .. .de ccc \\*[foo]\\ .. .de ddd \\*[bar]\\ .. . .aaa => foo .bbb => bar .ccc => ccc .ddd => ddd *Note Request and Macro Arguments::. 5.22 Page Motions ================= *Note Manipulating Spacing::, for a discussion of the main request for vertical motion, `sp'. -- Request: .mk [reg] -- Request: .rt [dist] The request `mk' can be used to mark a location on a page, for movement to later. This request takes a register name as an argument in which to store the current page location. With no argument it stores the location in an internal register. The results of this can be used later by the `rt' or the `sp' request (or the `\v' escape). The `rt' request returns _upwards_ to the location marked with the last `mk' request. If used with an argument, return to a position which distance from the top of the page is DIST (no previous call to `mk' is necessary in this case). Default scaling indicator is `v'. Here a primitive solution for a two-column macro. .nr column-length 1.5i .nr column-gap 4m .nr bottom-margin 1m . .de 2c . br . mk . ll \\n[column-length]u . wh -\\n[bottom-margin]u 2c-trap . nr right-side 0 .. . .de 2c-trap . ie \\n[right-side] \{\ . nr right-side 0 . po -(\\n[column-length]u + \\n[column-gap]u) . \" remove trap . wh -\\n[bottom-margin]u . \} . el \{\ . \" switch to right side . nr right-side 1 . po +(\\n[column-length]u + \\n[column-gap]u) . rt . \} .. . .pl 1.5i .ll 4i This is a small test which shows how the rt request works in combination with mk. .2c Starting here, text is typeset in two columns. Note that this implementation isn't robust and thus not suited for a real two-column macro. Result: This is a small test which shows how the rt request works in combination with mk. Starting here, isn't robust text is typeset and thus not in two columns. suited for a Note that this real two-column implementation macro. The following escapes give fine control of movements about the page. -- Escape: \v'e' Move vertically, usually from the current location on the page (if no absolute position operator `|' is used). The argument E specifies the distance to move; positive is downwards and negative upwards. The default scaling indicator for this escape is `v'. Beware, however, that `gtroff' continues text processing at the point where the motion ends, so you should always balance motions to avoid interference with text processing. `\v' doesn't trigger a trap. This can be quite useful; for example, consider a page bottom trap macro which prints a marker in the margin to indicate continuation of a footnote or something similar. There are some special-case escapes for vertical motion. -- Escape: \r Move upwards 1v. -- Escape: \u Move upwards .5v. -- Escape: \d Move down .5v. -- Escape: \h'e' Move horizontally, usually from the current location (if no absolute position operator `|' is used). The expression E indicates how far to move: positive is rightwards and negative leftwards. The default scaling indicator for this escape is `m'. This horizontal space is not discarded at the end of a line. To insert discardable space of a certain length use the `ss' request. There are a number of special-case escapes for horizontal motion. -- Escape: \ An unbreakable and unpaddable (i.e. not expanded during filling) space. (Note: This is a backslash followed by a space.) -- Escape: \~ An unbreakable space that stretches like a normal inter-word space when a line is adjusted. -- Escape: \| A 1/6th em space. Ignored for TTY output devices (rounded to zero). However, if there is a glyph defined in the current font file with name `\|' (note the leading backslash), the width of this glyph is used instead (even for TTYs). -- Escape: \^ A 1/12th em space. Ignored for TTY output devices (rounded to zero). However, if there is a glyph defined in the current font file with name `\^' (note the leading backslash), the width of this glyph is used instead (even for TTYs). -- Escape: \0 A space the size of a digit. The following string sets the TeX logo: .ds TeX T\h'-.1667m'\v'.224m'E\v'-.224m'\h'-.125m'X -- Escape: \w'text' -- Register: \n[st] -- Register: \n[sb] -- Register: \n[rst] -- Register: \n[rsb] -- Register: \n[ct] -- Register: \n[ssc] -- Register: \n[skw] Return the width of the specified TEXT in basic units. This allows horizontal movement based on the width of some arbitrary text (e.g. given as an argument to a macro). The length of the string `abc' is \w'abc'u. => The length of the string `abc' is 72u. Font changes may occur in TEXT which don't affect current settings. After use, `\w' sets several registers: `st' `sb' The highest and lowest point of the baseline, respectively, in TEXT. `rst' `rsb' Like the `st' and `sb' registers, but takes account of the heights and depths of glyphs. In other words, this gives the highest and lowest point of TEXT. Values below the baseline are negative. `ct' Defines the kinds of glyphs occurring in TEXT: 0 only short glyphs, no descenders or tall glyphs. 1 at least one descender. 2 at least one tall glyph. 3 at least one each of a descender and a tall glyph. `ssc' The amount of horizontal space (possibly negative) that should be added to the last glyph before a subscript. `skw' How far to right of the center of the last glyph in the `\w' argument, the center of an accent from a roman font should be placed over that glyph. -- Escape: \kp -- Escape: \k(ps -- Escape: \k[position] Store the current horizontal position in the _input_ line in number register with name POSITION (one-character name P, two-character name PS). Use this, for example, to return to the beginning of a string for highlighting or other decoration. -- Register: \n[hp] The current horizontal position at the input line. -- Register: \n[.k] A read-only number register containing the current horizontal output position (relative to the current indentation). -- Escape: \o'abc' Overstrike glyphs A, B, C, ...; the glyphs are centered, and the resulting spacing is the largest width of the affected glyphs. -- Escape: \zg Print glyph G with zero width, i.e., without spacing. Use this to overstrike glyphs left-aligned. -- Escape: \Z'anything' Print ANYTHING, then restore the horizontal and vertical position. The argument may not contain tabs or leaders. The following is an example of a strike-through macro: .de ST .nr ww \w'\\$1' \Z@\v'-.25m'\l'\\n[ww]u'@\\$1 .. . This is .ST "a test" an actual emergency! 5.23 Drawing Requests ===================== `gtroff' provides a number of ways to draw lines and other figures on the page. Used in combination with the page motion commands (see *note Page Motions::, for more info), a wide variety of figures can be drawn. However, for complex drawings these operations can be quite cumbersome, and it may be wise to use graphic preprocessors like `gpic' or `ggrn'. *Note gpic::, and *note ggrn::, for more information. All drawing is done via escapes. -- Escape: \l'l' -- Escape: \l'lg' Draw a line horizontally. L is the length of the line to be drawn. If it is positive, start the line at the current location and draw to the right; its end point is the new current location. Negative values are handled differently: The line starts at the current location and draws to the left, but the current location doesn't move. L can also be specified absolutely (i.e. with a leading `|') which draws back to the beginning of the input line. Default scaling indicator is `m'. The optional second parameter G is a glyph to draw the line with. If this second argument is not specified, `gtroff' uses the underscore glyph, `\[ru]'. To separate the two arguments (to prevent `gtroff' from interpreting a drawing glyph as a scaling indicator if the glyph is represented by a single character) use `\&'. Here a small useful example: .de box \[br]\\$*\[br]\l'|0\[rn]'\l'|0\[ul]' .. Note that this works by outputting a box rule (a vertical line), then the text given as an argument and then another box rule. Finally, the line drawing escapes both draw from the current location to the beginning of the _input_ line - this works because the line length is negative, not moving the current point. -- Escape: \L'l' -- Escape: \L'lg' Draw vertical lines. Its parameters are similar to the `\l' escape, except that the default scaling indicator is `v'. The movement is downwards for positive values, and upwards for negative values. The default glyph is the box rule glyph, `\[br]'. As with the vertical motion escapes, text processing blindly continues where the line ends. This is a \L'3v'test. Here the result, produced with `grotty'. This is a | | |test. -- Escape: \D'command arg ...' The `\D' escape provides a variety of drawing functions. Note that on character devices, only vertical and horizontal lines are supported within `grotty'; other devices may only support a subset of the available drawing functions. The default scaling indicator for all subcommands of `\D' is `m' for horizontal distances and `v' for vertical ones. Exceptions are `\D'f ...'' and `\D't ...'' which use `u' as the default, and `\D'FX ...'' which arguments are treated similar to the `defcolor' request. `\D'l DX DY'' Draw a line from the current location to the relative point specified by (DX,DY), where positive values mean down and right, respectively. The end point of the line is the new current location. The following example is a macro for creating a box around a text string; for simplicity, the box margin is taken as a fixed value, 0.2m. .de BOX . nr @wd \w'\\$1' \h'.2m'\ \h'-.2m'\v'(.2m - \\n[rsb]u)'\ \D'l 0 -(\\n[rst]u - \\n[rsb]u + .4m)'\ \D'l (\\n[@wd]u + .4m) 0'\ \D'l 0 (\\n[rst]u - \\n[rsb]u + .4m)'\ \D'l -(\\n[@wd]u + .4m) 0'\ \h'.2m'\v'-(.2m - \\n[rsb]u)'\ \\$1\ \h'.2m' .. First, the width of the string is stored in register `@wd'. Then, four lines are drawn to form a box, properly offset by the box margin. The registers `rst' and `rsb' are set by the `\w' escape, containing the largest height and depth of the whole string. `\D'c D'' Draw a circle with a diameter of D with the leftmost point at the current position. After drawing, the current location is positioned at the rightmost point of the circle. `\D'C D'' Draw a solid circle with the same parameters and behaviour as an outlined circle. No outline is drawn. `\D'e X Y'' Draw an ellipse with a horizontal diameter of X and a vertical diameter of Y with the leftmost point at the current position. After drawing, the current location is positioned at the rightmost point of the ellipse. `\D'E X Y'' Draw a solid ellipse with the same parameters and behaviour as an outlined ellipse. No outline is drawn. `\D'a DX1 DY1 DX2 DY2'' Draw an arc clockwise from the current location through the two specified relative locations (DX1,DY1) and (DX2,DY2). The coordinates of the first point are relative to the current position, and the coordinates of the second point are relative to the first point. After drawing, the current position is moved to the final point of the arc. `\D'~ DX1 DY1 DX2 DY2 ...'' Draw a spline from the current location to the relative point (DX1,DY1) and then to (DX2,DY2), and so on. The current position is moved to the terminal point of the drawn curve. `\D'f N'' Set the shade of gray to be used for filling solid objects to N; N must be an integer between 0 and 1000, where 0 corresponds solid white and 1000 to solid black, and values in between correspond to intermediate shades of gray. This applies only to solid circles, solid ellipses, and solid polygons. By default, a level of 1000 is used. Despite of being silly, the current point is moved horizontally to the right by N. Don't use this command! It has the serious drawback that it is always rounded to the next integer multiple of the horizontal resolution (the value of the `hor' keyword in the `DESC' file). Use `\M' (*note Colors::) or `\D'Fg ...'' instead. `\D'p DX1 DY1 DX2 DY2 ...'' Draw a polygon from the current location to the relative position (DX1,DY1) and then to (DX2,DY2) and so on. When the specified data points are exhausted, a line is drawn back to the starting point. The current position is changed by adding the sum of all arguments with odd index to the actual horizontal position and the even ones to the vertical position. `\D'P DX1 DY1 DX2 DY2 ...'' Draw a solid polygon with the same parameters and behaviour as an outlined polygon. No outline is drawn. Here a better variant of the box macro to fill the box with some color. Note that the box must be drawn before the text since colors in `gtroff' are not transparent; the filled polygon would hide the text completely. .de BOX . nr @wd \w'\\$1' \h'.2m'\ \h'-.2m'\v'(.2m - \\n[rsb]u)'\ \M[lightcyan]\ \D'P 0 -(\\n[rst]u - \\n[rsb]u + .4m) \ (\\n[@wd]u + .4m) 0 \ 0 (\\n[rst]u - \\n[rsb]u + .4m) \ -(\\n[@wd]u + .4m) 0'\ \h'.2m'\v'-(.2m - \\n[rsb]u)'\ \M[]\ \\$1\ \h'.2m' .. If you want a filled polygon which has exactly the same size as an unfilled one, you must draw both an unfilled and a filled polygon. A filled polygon is always smaller than an unfilled one because the latter uses straight lines with a given line thickness to connect the polygon's corners, while the former simply fills the area defined by the coordinates. \h'1i'\v'1i'\ \# increase line thickness \Z'\D't 5p''\ \# draw unfilled polygon \Z'\D'p 3 3 -6 0''\ \# draw filled polygon \Z'\D'P 3 3 -6 0'' `\D't N'' Set the current line thickness to N machine units. A value of zero selects the smallest available line thickness. A negative value makes the line thickness proportional to the current point size (this is the default behaviour of AT&T `troff'). Despite of being silly, the current point is moved horizontally to the right by N. `\D'FSCHEME COLOR_COMPONENTS'' Change current fill color. SCHEME is a single letter denoting the color scheme: `r' (rgb), `c' (cmy), `k' (cmyk), `g' (gray), or `d' (default color). The color components use exactly the same syntax as in the `defcolor' request (*note Colors::); the command `\D'Fd'' doesn't take an argument. _No_ position changing! Examples: \D'Fg .3' \" same gray as \D'f 700' \D'Fr #0000ff' \" blue *Note Graphics Commands::. -- Escape: \b'string' "Pile" a sequence of glyphs vertically, and center it vertically on the current line. Use it to build large brackets and braces. Here an example how to create a large opening brace: \b'\[lt]\[bv]\[lk]\[bv]\[lb]' The first glyph is on the top, the last glyph in STRING is at the bottom. Note that `gtroff' separates the glyphs vertically by 1m, and the whole object is centered 0.5m above the current baseline; the largest glyph width is used as the width for the whole object. This rather unflexible positioning algorithm doesn't work with `-Tdvi' since the bracket pieces vary in height for this device. Instead, use the `eqn' preprocessor. *Note Manipulating Spacing::, how to adjust the vertical spacing with the `\x' escape. 5.24 Traps ========== "Traps" are locations, which, when reached, call a specified macro. These traps can occur at a given location on the page, at a given location in the current diversion, at a blank line, after a certain number of input lines, or at the end of input. Setting a trap is also called "planting". It is also said that a trap is "sprung" if the associated macro is executed. 5.24.1 Page Location Traps -------------------------- "Page location traps" perform an action when `gtroff' reaches or passes a certain vertical location on the page. Page location traps have a variety of purposes, including: * setting headers and footers * setting body text in multiple columns * setting footnotes -- Request: .vpt flag -- Register: \n[.vpt] Enable vertical position traps if FLAG is non-zero, or disables them otherwise. Vertical position traps are traps set by the `wh' or `dt' requests. Traps set by the `it' request are not vertical position traps. The parameter that controls whether vertical position traps are enabled is global. Initially vertical position traps are enabled. The current setting of this is available in the `.vpt' read-only number register. Note that a page can't be ejected if `vpt' is set to zero. -- Request: .wh dist [macro] Set a page location trap. Non-negative values for DIST set the trap relative to the top of the page; negative values set the trap relative to the bottom of the page. Default scaling indicator is `v'; values of DIST are always rounded to be multiples of the vertical resolution (as given in register `.V'). MACRO is the name of the macro to execute when the trap is sprung. If MACRO is missing, remove the first trap (if any) at DIST. The following is a simple example of how many macro packages set headers and footers. .de hd \" Page header ' sp .5i . tl 'Title''date' ' sp .3i .. . .de fo \" Page footer ' sp 1v . tl ''%'' ' bp .. . .wh 0 hd \" trap at top of the page .wh -1i fo \" trap one inch from bottom A trap at or below the bottom of the page is ignored; it can be made active by either moving it up or increasing the page length so that the trap is on the page. Negative trap values always use the _current_ page length; they are not converted to an absolute vertical position: .pl 5i .wh -1i xx .ptr => xx -240 .pl 100i .ptr => xx -240 It is possible to have more than one trap at the same location; to do so, the traps must be defined at different locations, then moved together with the `ch' request; otherwise the second trap would replace the first one. Earlier defined traps hide later defined traps if moved to the same position (the many empty lines caused by the `bp' request are omitted in the following example): .de a . nop a .. .de b . nop b .. .de c . nop c .. . .wh 1i a .wh 2i b .wh 3i c .bp => a b c .ch b 1i .ch c 1i .bp => a .ch a 0.5i .bp => a b -- Register: \n[.t] A read-only number register holding the distance to the next trap. If there are no traps between the current position and the bottom of the page, it contains the distance to the page bottom. In a diversion, the distance to the page bottom is infinite (the returned value is the biggest integer which can be represented in `groff') if there are no diversion traps. -- Request: .ch macro [dist] Change the location of a trap. The first argument is the name of the macro to be invoked at the trap, and the second argument is the new location for the trap (note that the parameters are specified in opposite order as in the `wh' request). This is useful for building up footnotes in a diversion to allow more space at the bottom of the page for them. Default scaling indicator for DIST is `v'. If DIST is missing, the trap is removed. -- Register: \n[.ne] The read-only number register `.ne' contains the amount of space that was needed in the last `ne' request that caused a trap to be sprung. Useful in conjunction with the `.trunc' register. *Note Page Control::, for more information. Since the `.ne' register is only set by traps it doesn't make much sense to use it outside of trap macros. -- Register: \n[.trunc] A read-only register containing the amount of vertical space truncated by the most recently sprung vertical position trap, or, if the trap was sprung by an `ne' request, minus the amount of vertical motion produced by the `ne' request. In other words, at the point a trap is sprung, it represents the difference of what the vertical position would have been but for the trap, and what the vertical position actually is. Since the `.trunc' register is only set by traps it doesn't make much sense to use it outside of trap macros. -- Register: \n[.pe] A read-only register which is set to 1 while a page is ejected with the `bp' request (or by the end of input). Outside of traps this register is always zero. In the following example, only the second call to `x' is caused by `bp'. .de x \&.pe=\\n[.pe] .br .. .wh 1v x .wh 4v x A line. .br Another line. .br => A line. .pe=0 Another line. .pe=1 An important fact to consider while designing macros is that diversions and traps do not interact normally. For example, if a trap invokes a header macro (while outputting a diversion) which tries to change the font on the current page, the effect is not visible before the diversion has completely been printed (except for input protected with `\!' or `\?') since the data in the diversion is already formatted. In most cases, this is not the expected behaviour. 5.24.2 Diversion Traps ---------------------- -- Request: .dt [dist macro] Set a trap _within_ a diversion. DIST is the location of the trap (identical to the `wh' request; default scaling indicator is `v') and MACRO is the name of the macro to be invoked. If called without arguments, the diversion trap is removed. Note that there exists only a single diversion trap. The number register `.t' still works within diversions. *Note Diversions::, for more information. 5.24.3 Input Line Traps ----------------------- -- Request: .it n macro -- Request: .itc n macro Set an input line trap. N is the number of lines of input which may be read before springing the trap, MACRO is the macro to be invoked. Request lines are not counted as input lines. For example, one possible use is to have a macro which prints the next N lines in a bold font. .de B . it \\$1 B-end . ft B .. . .de B-end . ft R .. The `itc' request is identical except that an interrupted text line (ending with `\c') is not counted as a separate line. Both requests are associated with the current environment (*note Environments::); switching to another environment disables the current input trap, and going back reactivates it, restoring the number of already processed lines. 5.24.4 Blank Line Traps ----------------------- -- Request: .blm macro Set a blank line trap. `gtroff' executes MACRO when it encounters a blank line in the input file. 5.24.5 Leading Spaces Traps --------------------------- -- Request: .lsm macro -- Register: \n[lsn] -- Register: \n[lss] Set a leading spaces trap. `gtroff' executes MACRO when it encounters leading spaces in an input line; the implicit line break which normally happens in this case is suppressed. A line consisting of spaces only, however, is treated as an empty line, possibly subject to an empty line macro set with the `blm' request. Leading spaces are removed from the input line before calling the leading spaces macro. The number of removed spaces is stored in register `lsn'; the horizontal space which would be emitted if there was no leading space macro is stored in register `lss'. Note that `lsn' and `lss' are available even if no leading space macro has been set. The first thing a leading space macro sees is a token. However, some escapes like `\f' or `\m' are handled on the fly (see *note Gtroff Internals::, for a complete list) without creating a token at all. Consider that a line starts with two spaces followed by `\fIfoo'. While skipping the spaces `\fI' is handled too so that groff's current font is properly set to `I', but the leading space macro only sees `foo', without the preceding `\fI'. If the macro should see the font escape you have to `protect' it with something which creates a token, for example with `\&\fIfoo'. 5.24.6 End-of-input Traps ------------------------- -- Request: .em macro Set a trap at the end of input. MACRO is executed after the last line of the input file has been processed. For example, if the document had to have a section at the bottom of the last page for someone to approve it, the `em' request could be used. .de approval \c . ne 3v . sp (\\n[.t]u - 3v) . in +4i . lc _ . br Approved:\t\a . sp Date:\t\t\a .. . .em approval The `\c' in the above example needs explanation. For historical reasons (and for compatibility with AT&T `troff'), the end macro exits as soon as it causes a page break and no remaining data is in the partially collected line. Let us assume that there is no `\c' in the above `approval' macro, and that the page is full and has been ended with, say, a `br' request. The `ne' request now causes the start of a new page, which in turn makes `troff' exit immediately for the reasons just described. In most situations this is not intended. To always force processing the whole end macro independently of this behaviour it is thus advisable to insert something which starts an empty partially filled line (`\c') whenever there is a chance that a page break can happen. In the above example, the call of the `ne' request assures that the remaining code stays on the same page, so we have to insert `\c' only once. The next example shows how to append three lines, then starting a new page unconditionally. Since `.ne 1' doesn't give the desired effect - there is always one line available or we are already at the beginning of the next page - we temporarily increase the page length by one line so that we can use `.ne 2'. .de EM .pl +1v \c .ne 2 line one .br \c .ne 2 line two .br \c .ne 2 line three .br .pl -1v \c 'bp .. .em EM Note that this specific feature affects only the first potential page break caused by the end macro; further page breaks emitted by the end macro are handled normally. Another possible use of the `em' request is to make `gtroff' emit a single large page instead of multiple pages. For example, one may want to produce a long plain-text file for reading on-screen. The idea is to set the page length at the beginning of the document to a very large value to hold all the text, and automatically adjust it to the exact height of the document after the text has been output. .de adjust-page-length . br . pl \\n[nl]u \" \n[nl] holds the current page length .. . .de single-page-mode . pl 99999 . em adjust-page-length .. . .\" activate the above code .single-page-mode Since only one end-of-input trap does exist and other macro packages may already use it, care must be taken not to break the mechanism. A simple solution would be to append the above macro to the macro package's end-of-input macro using the `.am' request. 5.25 Diversions =============== In `gtroff' it is possible to "divert" text into a named storage area. Due to the similarity to defining macros it is sometimes said to be stored in a macro. This is used for saving text for output at a later time, which is useful for keeping blocks of text on the same page, footnotes, tables of contents, and indices. For orthogonality it is said that `gtroff' is in the "top-level diversion" if no diversion is active (i.e., the data is diverted to the output device). Although the following requests can be used to create diversions, simply using an undefined diversion will cause it to be defined as empty. *Note Identifiers::. -- Request: .di macro -- Request: .da macro Begin a diversion. Like the `de' request, it takes an argument of a macro name to divert subsequent text into. The `da' macro appends to an existing diversion. `di' or `da' without an argument ends the diversion. The current partially-filled line is included into the diversion. See the `box' request below for an example. Note that switching to another (empty) environment (with the `ev' request) avoids the inclusion of the current partially-filled line. -- Request: .box macro -- Request: .boxa macro Begin (or append to) a diversion like the `di' and `da' requests. The difference is that `box' and `boxa' do not include a partially-filled line in the diversion. Compare this: Before the box. .box xxx In the box. .br .box After the box. .br => Before the box. After the box. .xxx => In the box. with this: Before the diversion. .di yyy In the diversion. .br .di After the diversion. .br => After the diversion. .yyy => Before the diversion. In the diversion. `box' or `boxa' without an argument ends the diversion. -- Register: \n[.z] -- Register: \n[.d] Diversions may be nested. The read-only number register `.z' contains the name of the current diversion (this is a string-valued register). The read-only number register `.d' contains the current vertical place in the diversion. If not in a diversion it is the same as register `nl'. -- Register: \n[.h] The "high-water mark" on the current page. It corresponds to the text baseline of the lowest line on the page. This is a read-only register. .tm .h==\n[.h], nl==\n[nl] => .h==0, nl==-1 This is a test. .br .sp 2 .tm .h==\n[.h], nl==\n[nl] => .h==40, nl==120 As can be seen in the previous example, empty lines are not considered in the return value of the `.h' register. -- Register: \n[dn] -- Register: \n[dl] After completing a diversion, the read-write number registers `dn' and `dl' contain the vertical and horizontal size of the diversion. Note that only the just processed lines are counted: For the computation of `dn' and `dl', the requests `da' and `boxa' are handled as if `di' and `box' had been used - lines which have been already stored in a macro are not taken into account. .\" Center text both horizontally & vertically . .\" Enclose macro definitions in .eo and .ec .\" to avoid the doubling of the backslash .eo .\" macro .(c starts centering mode .de (c . br . ev (c . evc 0 . in 0 . nf . di @c .. .\" macro .)c terminates centering mode .de )c . br . ev . di . nr @s (((\n[.t]u - \n[dn]u) / 2u) - 1v) . sp \n[@s]u . ce 1000 . @c . ce 0 . sp \n[@s]u . br . fi . rr @s . rm @s . rm @c .. .\" End of macro definitions, restore escape mechanism .ec -- Escape: \! -- Escape: \?anything\? Prevent requests, macros, and escapes from being interpreted when read into a diversion. Both escapes take the given text and "transparently" embed it into the diversion. This is useful for macros which shouldn't be invoked until the diverted text is actually output. The `\!' escape transparently embeds text up to and including the end of the line. The `\?' escape transparently embeds text until the next occurrence of the `\?' escape. Example: \?ANYTHING\? ANYTHING may not contain newlines; use `\!' to embed newlines in a diversion. The escape sequence `\?' is also recognized in copy mode and turned into a single internal code; it is this code that terminates ANYTHING. Thus the following example prints 4. .nr x 1 .nf .di d \?\\?\\\\?\\\\\\\\nx\\\\?\\?\? .di .nr x 2 .di e .d .di .nr x 3 .di f .e .di .nr x 4 .f Both escapes read the data in copy mode. If `\!' is used in the top-level diversion, its argument is directly embedded into the `gtroff' intermediate output. This can be used for example to control a postprocessor which processes the data before it is sent to the device driver. The `\?' escape used in the top-level diversion produces no output at all; its argument is simply ignored. -- Request: .output string Emit STRING directly to the `gtroff' intermediate output (subject to copy mode interpretation); this is similar to `\!' used at the top level. An initial double quote in STRING is stripped off to allow initial blanks. This request can't be used before the first page has started - if you get an error, simply insert `.br' before the `output' request. Without argument, `output' is ignored. Use with caution! It is normally only needed for mark-up used by a postprocessor which does something with the output before sending it to the output device, filtering out STRING again. -- Request: .asciify div "Unformat" the diversion specified by DIV in such a way that ASCII characters, characters translated with the `trin' request, space characters, and some escape sequences that were formatted and diverted are treated like ordinary input characters when the diversion is reread. It can be also used for gross hacks; for example, the following sets register `n' to 1. .tr @. .di x @nr n 1 .br .di .tr @@ .asciify x .x Note that `asciify' cannot return all items in a diversion back to their source equivalent, nodes such as `\N[...]' will still remain as nodes, so the result cannot be guaranteed to be a pure string. *Note Copy-in Mode::. -- Request: .unformat div Like `asciify', unformat the specified diversion. However, `unformat' only unformats spaces and tabs between words. Unformatted tabs are treated as input tokens, and spaces are stretchable again. The vertical size of lines is not preserved; glyph information (font, font size, space width, etc.) is retained. 5.26 Environments ================= It happens frequently that some text should be printed in a certain format regardless of what may be in effect at the time, for example, in a trap invoked macro to print headers and footers. To solve this `gtroff' processes text in "environments". An environment contains most of the parameters that control text processing. It is possible to switch amongst these environments; by default `gtroff' processes text in environment 0. The following is the information kept in an environment. * font parameters (size, family, style, glyph height and slant, space and sentence space size) * page parameters (line length, title length, vertical spacing, line spacing, indentation, line numbering, centering, right-justifying, underlining, hyphenation data) * fill and adjust mode * tab stops, tab and leader characters, escape character, no-break and hyphen indicators, margin character data * partially collected lines * input traps * drawing and fill colours These environments may be given arbitrary names (see *note Identifiers::, for more info). Old versions of `troff' only had environments named `0', `1', and `2'. -- Request: .ev [env] -- Register: \n[.ev] Switch to another environment. The argument ENV is the name of the environment to switch to. With no argument, `gtroff' switches back to the previous environment. There is no limit on the number of named environments; they are created the first time that they are referenced. The `.ev' read-only register contains the name or number of the current environment. This is a string-valued register. Note that a call to `ev' (with argument) pushes the previously active environment onto a stack. If, say, environments `foo', `bar', and `zap' are called (in that order), the first `ev' request without parameter switches back to environment `bar' (which is popped off the stack), and a second call switches back to environment `foo'. Here is an example: .ev footnote-env .fam N .ps 6 .vs 8 .ll -.5i .ev ... .ev footnote-env \(dg Note the large, friendly letters. .ev -- Request: .evc env Copy the environment ENV into the current environment. The following environment data is not copied: * Partially filled lines. * The status whether the previous line was interrupted. * The number of lines still to center, or to right-justify, or to underline (with or without underlined spaces); they are set to zero. * The status whether a temporary indentation is active. * Input traps and its associated data. * Line numbering mode is disabled; it can be reactivated with `.nm +0'. * The number of consecutive hyphenated lines (set to zero). -- Register: \n[.w] -- Register: \n[.cht] -- Register: \n[.cdp] -- Register: \n[.csk] The `\n[.w]' register contains the width of the last glyph added to the current environment. The `\n[.cht]' register contains the height of the last glyph added to the current environment. The `\n[.cdp]' register contains the depth of the last glyph added to the current environment. It is positive for glyphs extending below the baseline. The `\n[.csk]' register contains the "skew" (how far to the right of the glyph's center that `gtroff' should place an accent) of the last glyph added to the current environment. -- Register: \n[.n] The `\n[.n]' register contains the length of the previous output line in the current environment. 5.27 Suppressing output ======================= -- Escape: \Onum Disable or enable output depending on the value of NUM: `\O0' Disable any glyphs from being emitted to the device driver, provided that the escape occurs at the outer level (see `\O[3]' and `\O[4]'). Motion is not suppressed so effectively `\O[0]' means _pen up_. `\O1' Enable output of glyphs, provided that the escape occurs at the outer level. `\O0' and `\O1' also reset the four registers `opminx', `opminy', `opmaxx', and `opmaxy' to -1. *Note Register Index::. These four registers mark the top left and bottom right hand corners of a box which encompasses all written glyphs. For example the input text: Hello \O[0]world \O[1]this is a test. produces the following output: Hello this is a test. `\O2' Provided that the escape occurs at the outer level, enable output of glyphs and also write out to `stderr' the page number and four registers encompassing the glyphs previously written since the last call to `\O'. `\O3' Begin a nesting level. At start-up, `gtroff' is at outer level. The current level is contained within the read-only register `.O'. *Note Built-in Registers::. `\O4' End a nesting level. The current level is contained within the read-only register `.O'. *Note Built-in Registers::. `\O[5PFILENAME]' This escape is `grohtml' specific. Provided that this escape occurs at the outer nesting level write the `filename' to `stderr'. The position of the image, P, must be specified and must be one of `l', `r', `c', or `i' (left, right, centered, inline). FILENAME is associated with the production of the next inline image. 5.28 Colors =========== -- Request: .color [n] -- Register: \n[.color] If N is missing or non-zero, activate colors (this is the default); otherwise, turn it off. The read-only number register `.color' is 1 if colors are active, 0 otherwise. Internally, `color' sets a global flag; it does not produce a token. Similar to the `cp' request, you should use it at the beginning of your document to control color output. Colors can be also turned off with the `-c' command line option. -- Request: .defcolor ident scheme color_components Define color with name IDENT. SCHEME can be one of the following values: `rgb' (three components), `cmy' (three components), `cmyk' (four components), and `gray' or `grey' (one component). Color components can be given either as a hexadecimal string or as positive decimal integers in the range 0-65535. A hexadecimal string contains all color components concatenated. It must start with either `#' or `##'; the former specifies hex values in the range 0-255 (which are internally multiplied by 257), the latter in the range 0-65535. Examples: `#FFC0CB' (pink), `##ffff0000ffff' (magenta). The default color name value is device-specific (usually black). It is possible that the default color for `\m' and `\M' is not identical. A new scaling indicator `f' has been introduced which multiplies its value by 65536; this makes it convenient to specify color components as fractions in the range 0 to 1 (1f equals 65536u). Example: .defcolor darkgreen rgb 0.1f 0.5f 0.2f Note that `f' is the default scaling indicator for the `defcolor' request, thus the above statement is equivalent to .defcolor darkgreen rgb 0.1 0.5 0.2 -- Request: .gcolor [color] -- Escape: \mc -- Escape: \m(co -- Escape: \m[color] -- Register: \n[.m] Set (glyph) drawing color. The following examples show how to turn the next four words red. .gcolor red these are in red .gcolor and these words are in black. \m[red]these are in red\m[] and these words are in black. The escape `\m[]' returns to the previous color, as does a call to `gcolor' without an argument. The name of the current drawing color is available in the read-only, string-valued number register `.m'. The drawing color is associated with the current environment (*note Environments::). Note that `\m' doesn't produce an input token in `gtroff'. As a consequence, it can be used in requests like `mc' (which expects a single character as an argument) to change the color on the fly: .mc \m[red]x\m[] -- Request: .fcolor [color] -- Escape: \Mc -- Escape: \M(co -- Escape: \M[color] -- Register: \n[.M] Set fill (background) color for filled objects drawn with the `\D'...'' commands. A red ellipse can be created with the following code: \M[red]\h'0.5i'\D'E 2i 1i'\M[] The escape `\M[]' returns to the previous fill color, as does a call to `fcolor' without an argument. The name of the current fill (background) color is available in the read-only, string-valued number register `.M'. The fill color is associated with the current environment (*note Environments::). Note that `\M' doesn't produce an input token in `gtroff'. 5.29 I/O ======== `gtroff' has several requests for including files: -- Request: .so file Read in the specified FILE and includes it in place of the `so' request. This is quite useful for large documents, e.g. keeping each chapter in a separate file. *Note gsoelim::, for more information. Since `gtroff' replaces the `so' request with the contents of `file', it makes a difference whether the data is terminated with a newline or not: Assuming that file `xxx' contains the word `foo' without a final newline, this This is .so xxx bar yields `This is foobar'. The search path for FILE can be controlled with the `-I' command line option. -- Request: .pso command Read the standard output from the specified COMMAND and includes it in place of the `pso' request. This request causes an error if used in safer mode (which is the default). Use `groff''s or `troff''s `-U' option to activate unsafe mode. The comment regarding a final newline for the `so' request is valid for `pso' also. -- Request: .mso file Identical to the `so' request except that `gtroff' searches for the specified FILE in the same directories as macro files for the the `-m' command line option. If the file name to be included has the form `NAME.tmac' and it isn't found, `mso' tries to include `tmac.NAME' and vice versa. If the file does not exist, a warning of type `file' is emitted. *Note Debugging::, for information about warnings. -- Request: .trf file -- Request: .cf file Transparently output the contents of FILE. Each line is output as if it were preceded by `\!'; however, the lines are _not_ subject to copy mode interpretation. If the file does not end with a newline, then a newline is added (`trf' only). For example, to define a macro `x' containing the contents of file `f', use .ev 1 .di x .trf f .di .ev The calls to `ev' prevent that the current partial input line becomes part of the diversion. Both `trf' and `cf', when used in a diversion, embeds an object in the diversion which, when reread, causes the contents of FILE to be transparently copied through to the output. In UNIX `troff', the contents of FILE is immediately copied through to the output regardless of whether there is a current diversion; this behaviour is so anomalous that it must be considered a bug. While `cf' copies the contents of FILE completely unprocessed, `trf' disallows characters such as NUL that are not valid `gtroff' input characters (*note Identifiers::). For `cf', within a diversion, `completely unprocessed' means that each line of a file to be inserted is handled as if it were preceded by `\!\\!'. Both requests cause a line break. -- Request: .nx [file] Force `gtroff' to continue processing of the file specified as an argument. If no argument is given, immediately jump to the end of file. -- Request: .rd [prompt [arg1 arg2 ...]] Read from standard input, and include what is read as though it were part of the input file. Text is read until a blank line is encountered. If standard input is a TTY input device (keyboard), write PROMPT to standard error, followed by a colon (or send BEL for a beep if no argument is given). Arguments after PROMPT are available for the input. For example, the line .rd data foo bar with the input `This is \$2.' prints This is bar. Using the `nx' and `rd' requests, it is easy to set up form letters. The form letter template is constructed like this, putting the following lines into a file called `repeat.let': .ce \*(td .sp 2 .nf .rd .sp .rd .fi Body of letter. .bp .nx repeat.let When this is run, a file containing the following lines should be redirected in. Note that requests included in this file are executed as though they were part of the form letter. The last block of input is the `ex' request which tells `groff' to stop processing. If this was not there, `groff' would not know when to stop. Trent A. Fisher 708 NW 19th Av., #202 Portland, OR 97209 Dear Trent, Len Adollar 4315 Sierra Vista San Diego, CA 92103 Dear Mr. Adollar, .ex -- Request: .pi pipe Pipe the output of `gtroff' to the shell command(s) specified by PIPE. This request must occur before `gtroff' has a chance to print anything. `pi' causes an error if used in safer mode (which is the default). Use `groff''s or `troff''s `-U' option to activate unsafe mode. Multiple calls to `pi' are allowed, acting as a chain. For example, .pi foo .pi bar ... is the same as `.pi foo | bar'. Note that the intermediate output format of `gtroff' is piped to the specified commands. Consequently, calling `groff' without the `-Z' option normally causes a fatal error. -- Request: .sy cmds -- Register: \n[systat] Execute the shell command(s) specified by CMDS. The output is not saved anyplace, so it is up to the user to do so. This request causes an error if used in safer mode (which is the default). Use `groff''s or `troff''s `-U' option to activate unsafe mode. For example, the following code fragment introduces the current time into a document: .sy perl -e 'printf ".nr H %d\\n.nr M %d\\n.nr S %d\\n",\ (localtime(time))[2,1,0]' > /tmp/x\n[$$] .so /tmp/x\n[$$] .sy rm /tmp/x\n[$$] \nH:\nM:\nS Note that this works by having the `perl' script (run by `sy') print out the `nr' requests which set the number registers `H', `M', and `S', and then reads those commands in with the `so' request. For most practical purposes, the number registers `seconds', `minutes', and `hours' which are initialized at start-up of `gtroff' should be sufficient. Use the `af' request to get a formatted output: .af hours 00 .af minutes 00 .af seconds 00 \n[hours]:\n[minutes]:\n[seconds] The `systat' read-write number register contains the return value of the `system()' function executed by the last `sy' request. -- Request: .open stream file -- Request: .opena stream file Open the specified FILE for writing and associates the specified STREAM with it. The `opena' request is like `open', but if the file exists, append to it instead of truncating it. Both `open' and `opena' cause an error if used in safer mode (which is the default). Use `groff''s or `troff''s `-U' option to activate unsafe mode. -- Request: .write stream data -- Request: .writec stream data Write to the file associated with the specified STREAM. The stream must previously have been the subject of an open request. The remainder of the line is interpreted as the `ds' request reads its second argument: A leading `"' is stripped, and it is read in copy-in mode. The `writec' request is like `write', but only `write' appends a newline to the data. -- Request: .writem stream xx Write the contents of the macro or string XX to the file associated with the specified STREAM. XX is read in copy mode, i.e., already formatted elements are ignored. Consequently, diversions must be unformatted with the `asciify' request before calling `writem'. Usually, this means a loss of information. -- Request: .close stream Close the specified STREAM; the stream is no longer an acceptable argument to the `write' request. Here a simple macro to write an index entry. .open idx test.idx . .de IX . write idx \\n[%] \\$* .. . .IX test entry . .close idx -- Escape: \Ve -- Escape: \V(ev -- Escape: \V[env] Interpolate the contents of the specified environment variable ENV (one-character name E, two-character name EV) as returned by the function `getenv'. `\V' is interpreted in copy-in mode. 5.30 Postprocessor Access ========================= There are two escapes which give information directly to the postprocessor. This is particularly useful for embedding POSTSCRIPT into the final document. -- Request: .device xxx -- Escape: \X'xxx' Embeds its argument into the `gtroff' output preceded with `x X'. The escapes `\&', `\)', `\%', and `\:' are ignored within `\X', `\ ' and `\~' are converted to single space characters. All other escapes (except `\\' which produces a backslash) cause an error. Contrary to `\X', the `device' request simply processes its argument in copy mode (*note Copy-in Mode::). If the `use_charnames_in_special' keyword is set in the `DESC' file, special characters no longer cause an error; they are simply output verbatim. Additionally, the backslash is represented as `\\'. `use_charnames_in_special' is currently used by `grohtml' only. -- Request: .devicem xx -- Escape: \Yn -- Escape: \Y(nm -- Escape: \Y[name] This is approximately equivalent to `\X'\*[NAME]'' (one-character name N, two-character name NM). However, the contents of the string or macro NAME are not interpreted; also it is permitted for NAME to have been defined as a macro and thus contain newlines (it is not permitted for the argument to `\X' to contain newlines). The inclusion of newlines requires an extension to the UNIX `troff' output format, and confuses drivers that do not know about this extension (*note Device Control Commands::). *Note Output Devices::. 5.31 Miscellaneous ================== This section documents parts of `gtroff' which cannot (yet) be categorized elsewhere in this manual. -- Request: .nm [start [inc [space [indent]]]] Print line numbers. START is the line number of the _next_ output line. INC indicates which line numbers are printed. For example, the value 5 means to emit only line numbers which are multiples of 5; this defaults to 1. SPACE is the space to be left between the number and the text; this defaults to one digit space. The fourth argument is the indentation of the line numbers, defaulting to zero. Both SPACE and INDENT are given as multiples of digit spaces; they can be negative also. Without any arguments, line numbers are turned off. `gtroff' reserves three digit spaces for the line number (which is printed right-justified) plus the amount given by INDENT; the output lines are concatenated to the line numbers, separated by SPACE, and _without_ reducing the line length. Depending on the value of the horizontal page offset (as set with the `po' request), line numbers which are longer than the reserved space stick out to the left, or the whole line is moved to the right. Parameters corresponding to missing arguments are not changed; any non-digit argument (to be more precise, any argument starting with a character valid as a delimiter for identifiers) is also treated as missing. If line numbering has been disabled with a call to `nm' without an argument, it can be reactivated with `.nm +0', using the previously active line numbering parameters. The parameters of `nm' are associated with the current environment (*note Environments::). The current output line number is available in the number register `ln'. .po 1m .ll 2i This test shows how line numbering works with groff. .nm 999 This test shows how line numbering works with groff. .br .nm xxx 3 2 .ll -\w'0'u This test shows how line numbering works with groff. .nn 2 This test shows how line numbering works with groff. And here the result: This test shows how line numbering works 999 with groff. This 1000 test shows how line 1001 numbering works with 1002 groff. This test shows how line numbering works with groff. This test shows how 1005 line numbering works with groff. -- Request: .nn [skip] Temporarily turn off line numbering. The argument is the number of lines not to be numbered; this defaults to 1. -- Request: .mc glyph [dist] Print a "margin character" to the right of the text.(1) (*note Miscellaneous-Footnote-1::) The first argument is the glyph to be printed. The second argument is the distance away from the right margin. If missing, the previously set value is used; default is 10pt). For text lines that are too long (that is, longer than the text length plus DIST), the margin character is directly appended to the lines. With no arguments the margin character is turned off. If this occurs before a break, no margin character is printed. For compatibility with AT&T `troff', a call to `mc' to set the margin character can't be undone immediately; at least one line gets a margin character. Thus .ll 1i .mc \[br] .mc xxx .br xxx produces xxx | xxx For empty lines and lines produced by the `tl' request no margin character is emitted. The margin character is associated with the current environment (*note Environments::). This is quite useful for indicating text that has changed, and, in fact, there are programs available for doing this (they are called `nrchbar' and `changebar' and can be found in any `comp.sources.unix' archive). .ll 3i .mc | This paragraph is highlighted with a margin character. .sp Note that vertical space isn't marked. .br \& .br But we can fake it with `\&'. Result: This paragraph is highlighted | with a margin character. | Note that vertical space isn't | marked. | | But we can fake it with `\&'. | -- Request: .psbb filename -- Register: \n[llx] -- Register: \n[lly] -- Register: \n[urx] -- Register: \n[ury] Retrieve the bounding box of the POSTSCRIPT image found in FILENAME. The file must conform to Adobe's "Document Structuring Conventions" (DSC); the command searches for a `%%BoundingBox' comment and extracts the bounding box values into the number registers `llx', `lly', `urx', and `ury'. If an error occurs (for example, `psbb' cannot find the `%%BoundingBox' comment), it sets the four number registers to zero. The search path for FILENAME can be controlled with the `-I' command line option. (1) "Margin character" is a misnomer since it is an output glyph. 5.32 `gtroff' Internals ======================= `gtroff' processes input in three steps. One or more input characters are converted to an "input token".(1) (*note Gtroff Internals-Footnote-1::) Then, one or more input tokens are converted to an "output node". Finally, output nodes are converted to the intermediate output language understood by all output devices. Actually, before step one happens, `gtroff' converts certain escape sequences into reserved input characters (not accessible by the user); such reserved characters are used for other internal processing also - this is the very reason why not all characters are valid input. *Note Identifiers::, for more on this topic. For example, the input string `fi\[:u]' is converted into a character token `f', a character token `i', and a special token `:u' (representing u umlaut). Later on, the character tokens `f' and `i' are merged to a single output node representing the ligature glyph `fi' (provided the current font has a glyph for this ligature); the same happens with `:u'. All output glyph nodes are `processed' which means that they are invariably associated with a given font, font size, advance width, etc. During the formatting process, `gtroff' itself adds various nodes to control the data flow. Macros, diversions, and strings collect elements in two chained lists: a list of input tokens which have been passed unprocessed, and a list of output nodes. Consider the following the diversion. .di xxx a \!b c .br .di It contains these elements. node list token list element number line start node -- 1 glyph node `a' -- 2 word space node -- 3 -- `b' 4 -- `\n' 5 glyph node `c' -- 6 vertical size node -- 7 vertical size node -- 8 -- `\n' 9 Elements 1, 7, and 8 are inserted by `gtroff'; the latter two (which are always present) specify the vertical extent of the last line, possibly modified by `\x'. The `br' request finishes the current partial line, inserting a newline input token which is subsequently converted to a space when the diversion is reread. Note that the word space node has a fixed width which isn't stretchable anymore. To convert horizontal space nodes back to input tokens, use the `unformat' request. Macros only contain elements in the token list (and the node list is empty); diversions and strings can contain elements in both lists. Note that the `chop' request simply reduces the number of elements in a macro, string, or diversion by one. Exceptions are "compatibility save" and "compatibility ignore" input tokens which are ignored. The `substring' request also ignores those input tokens. Some requests like `tr' or `cflags' work on glyph identifiers only; this means that the associated glyph can be changed without destroying this association. This can be very helpful for substituting glyphs. In the following example, we assume that glyph `foo' isn't available by default, so we provide a substitution using the `fchar' request and map it to input character `x'. .fchar \[foo] foo .tr x \[foo] Now let us assume that we install an additional special font `bar' which has glyph `foo'. .special bar .rchar \[foo] Since glyphs defined with `fchar' are searched before glyphs in special fonts, we must call `rchar' to remove the definition of the fallback glyph. Anyway, the translation is still active; `x' now maps to the real glyph `foo'. Macro and request arguments preserve the compatibility mode: .cp 1 \" switch to compatibility mode .de xx \\$1 .. .cp 0 \" switch compatibility mode off .xx caf\['e] => café Since compatibility mode is on while `de' is called, the macro `xx' activates compatibility mode while executing. Argument `$1' can still be handled properly because it inherits the compatibility mode status which was active at the point where `xx' is called. After expansion of the parameters, the compatibility save and restore tokens are removed. (1) Except the escapes `\f', `\F', `\H', `\m', `\M', `\R', `\s', and `\S' which are processed immediately if not in copy-in mode. 5.33 Debugging ============== `gtroff' is not easy to debug, but there are some useful features and strategies for debugging. -- Request: .lf line [filename] Change the line number and optionally the file name `gtroff' shall use for error and warning messages. LINE is the input line number of the _next_ line. Without argument, the request is ignored. This is a debugging aid for documents which are split into many files, then put together with `soelim' and other preprocessors. Usually, it isn't invoked manually. Note that other `troff' implementations (including the original AT&T version) handle `lf' differently. For them, LINE changes the line number of the _current_ line. -- Request: .tm string -- Request: .tm1 string -- Request: .tmc string Send STRING to the standard error output; this is very useful for printing debugging messages among other things. STRING is read in copy mode. The `tm' request ignores leading spaces of STRING; `tm1' handles its argument similar to the `ds' request: a leading double quote in STRING is stripped to allow initial blanks. The `tmc' request is similar to `tm1' but does not append a newline (as is done in `tm' and `tm1'). -- Request: .ab [string] Similar to the `tm' request, except that it causes `gtroff' to stop processing. With no argument it prints `User Abort.' to standard error. -- Request: .ex The `ex' request also causes `gtroff' to stop processing; see also *note I/O::. When doing something involved it is useful to leave the debugging statements in the code and have them turned on by a command line flag. .if \n(DB .tm debugging output To activate these statements say groff -rDB=1 file If it is known in advance that there are many errors and no useful output, `gtroff' can be forced to suppress formatted output with the `-z' flag. -- Request: .pev Print the contents of the current environment and all the currently defined environments (both named and numbered) on `stderr'. -- Request: .pm Print the entire symbol table on `stderr'. Names of all defined macros, strings, and diversions are print together with their size in bytes. Since `gtroff' sometimes adds nodes by itself, the returned size can be larger than expected. This request differs from UNIX `troff': `gtroff' reports the sizes of diversions, ignores an additional argument to print only the total of the sizes, and the size isn't returned in blocks of 128 characters. -- Request: .pnr Print the names and contents of all currently defined number registers on `stderr'. -- Request: .ptr Print the names and positions of all traps (not including input line traps and diversion traps) on `stderr'. Empty slots in the page trap list are printed as well, because they can affect the priority of subsequently planted traps. -- Request: .fl Instruct `gtroff' to flush its output immediately. The intent is for interactive use, but this behaviour is currently not implemented in `gtroff'. Contrary to UNIX `troff', TTY output is sent to a device driver also (`grotty'), making it non-trivial to communicate interactively. This request causes a line break. -- Request: .backtrace Print a backtrace of the input stack to the standard error stream. Consider the following in file `test': .de xxx . backtrace .. .de yyy . xxx .. . .yyy On execution, `gtroff' prints the following: test:2: backtrace: macro `xxx' test:5: backtrace: macro `yyy' test:8: backtrace: file `test' The option `-b' of `gtroff' internally calls a variant of this request on each error and warning. -- Register: \n[slimit] Use the `slimit' number register to set the maximum number of objects on the input stack. If `slimit' is less than or equal to 0, there is no limit set. With no limit, a buggy recursive macro can exhaust virtual memory. The default value is 1000; this is a compile-time constant. -- Request: .warnscale si Set the scaling indicator used in warnings to SI. Valid values for SI are `u', `i', `c', `p', and `P'. At startup, it is set to `i'. -- Request: .spreadwarn [limit] Make `gtroff' emit a warning if the additional space inserted for each space between words in an output line is larger or equal to LIMIT. A negative value is changed to zero; no argument toggles the warning on and off without changing LIMIT. The default scaling indicator is `m'. At startup, `spreadwarn' is deactivated, and LIMIT is set to 3m. For example, .spreadwarn 0.2m causes a warning if `gtroff' must add 0.2m or more for each interword space in a line. This request is active only if text is justified to both margins (using `.ad b'). `gtroff' has command line options for printing out more warnings (`-w') and for printing backtraces (`-b') when a warning or an error occurs. The most verbose level of warnings is `-ww'. -- Request: .warn [flags] -- Register: \n[.warn] Control the level of warnings checked for. The FLAGS are the sum of the numbers associated with each warning that is to be enabled; all other warnings are disabled. The number associated with each warning is listed below. For example, `.warn 0' disables all warnings, and `.warn 1' disables all warnings except that about missing glyphs. If no argument is given, all warnings are enabled. The read-only number register `.warn' contains the current warning level. 5.33.1 Warnings --------------- The warnings that can be given to `gtroff' are divided into the following categories. The name associated with each warning is used by the `-w' and `-W' options; the number is used by the `warn' request and by the `.warn' register. `char' `1' Non-existent glyphs.(1) (*note Warnings-Footnote-1::) This is enabled by default. `number' `2' Invalid numeric expressions. This is enabled by default. *Note Expressions::. `break' `4' In fill mode, lines which could not be broken so that their length was less than the line length. This is enabled by default. `delim' `8' Missing or mismatched closing delimiters. `el' `16' Use of the `el' request with no matching `ie' request. *Note if-else::. `scale' `32' Meaningless scaling indicators. `range' `64' Out of range arguments. `syntax' `128' Dubious syntax in numeric expressions. `di' `256' Use of `di' or `da' without an argument when there is no current diversion. `mac' `512' Use of undefined strings, macros and diversions. When an undefined string, macro, or diversion is used, that string is automatically defined as empty. So, in most cases, at most one warning is given for each name. `reg' `1024' Use of undefined number registers. When an undefined number register is used, that register is automatically defined to have a value of 0. So, in most cases, at most one warning is given for use of a particular name. `tab' `2048' Use of a tab character where a number was expected. `right-brace' `4096' Use of `\}' where a number was expected. `missing' `8192' Requests that are missing non-optional arguments. `input' `16384' Invalid input characters. `escape' `32768' Unrecognized escape sequences. When an unrecognized escape sequence `\X' is encountered, the escape character is ignored, and X is printed. `space' `65536' Missing space between a request or macro and its argument. This warning is given when an undefined name longer than two characters is encountered, and the first two characters of the name make a defined name. The request or macro is not invoked. When this warning is given, no macro is automatically defined. This is enabled by default. This warning never occurs in compatibility mode. `font' `131072' Non-existent fonts. This is enabled by default. `ig' `262144' Invalid escapes in text ignored with the `ig' request. These are conditions that are errors when they do not occur in ignored text. `color' `524288' Color related warnings. `file' `1048576' Missing files. The `mso' request gives this warning when the requested macro file does not exist. This is enabled by default. `all' All warnings except `di', `mac' and `reg'. It is intended that this covers all warnings that are useful with traditional macro packages. `w' All warnings. (1) `char' is a misnomer since it reports missing glyphs - there aren't missing input characters, only invalid ones. 5.34 Implementation Differences =============================== GNU `troff' has a number of features which cause incompatibilities with documents written with old versions of `troff'. Long names cause some incompatibilities. UNIX `troff' interprets .dsabcd as defining a string `ab' with contents `cd'. Normally, GNU `troff' interprets this as a call of a macro named `dsabcd'. Also UNIX `troff' interprets `\*[' or `\n[' as references to a string or number register called `['. In GNU `troff', however, this is normally interpreted as the start of a long name. In compatibility mode GNU `troff' interprets long names in the traditional way (which means that they are not recognized as names). -- Request: .cp [n] -- Request: .do cmd -- Register: \n[.C] If N is missing or non-zero, turn on compatibility mode; otherwise, turn it off. The read-only number register `.C' is 1 if compatibility mode is on, 0 otherwise. Compatibility mode can be also turned on with the `-C' command line option. The `do' request turns off compatibility mode while executing its arguments as a `gtroff' command. However, it does not turn off compatibility mode while processing the macro itself. To do that, use the `de1' request (or manipulate the `.C' register manually). *Note Writing Macros::. .do fam T executes the `fam' request when compatibility mode is enabled. `gtroff' restores the previous compatibility setting before interpreting any files sourced by the CMD. Two other features are controlled by `-C'. If not in compatibility mode, GNU `troff' preserves the input level in delimited arguments: .ds xx ' \w'abc\*(xxdef' In compatibility mode, the string `72def'' is returned; without `-C' the resulting string is `168' (assuming a TTY output device). Finally, the escapes `\f', `\H', `\m', `\M', `\R', `\s', and `\S' are transparent for recognizing the beginning of a line only in compatibility mode (this is a rather obscure feature). For example, the code .de xx Hallo! .. \fB.xx\fP prints `Hallo!' in bold face if in compatibility mode, and `.xx' in bold face otherwise. GNU `troff' does not allow the use of the escape sequences `\|', `\^', `\&', `\{', `\}', `\', `\'', `\`', `\-', `\_', `\!', `\%', and `\c' in names of strings, macros, diversions, number registers, fonts or environments; UNIX `troff' does. The `\A' escape sequence (*note Identifiers::) may be helpful in avoiding use of these escape sequences in names. Fractional point sizes cause one noteworthy incompatibility. In UNIX `troff' the `ps' request ignores scale indicators and thus .ps 10u sets the point size to 10 points, whereas in GNU `troff' it sets the point size to 10 scaled points. *Note Fractional Type Sizes::, for more information. In GNU `troff' there is a fundamental difference between (unformatted) input characters and (formatted) output glyphs. Everything that affects how a glyph is output is stored with the glyph node; once a glyph node has been constructed it is unaffected by any subsequent requests that are executed, including `bd', `cs', `tkf', `tr', or `fp' requests. Normally glyphs are constructed from input characters at the moment immediately before the glyph is added to the current output line. Macros, diversions and strings are all, in fact, the same type of object; they contain lists of input characters and glyph nodes in any combination. A glyph node does not behave like an input character for the purposes of macro processing; it does not inherit any of the special properties that the input character from which it was constructed might have had. For example, .di x \\\\ .br .di .x prints `\\' in GNU `troff'; each pair of input backslashes is turned into one output backslash and the resulting output backslashes are not interpreted as escape characters when they are reread. UNIX `troff' would interpret them as escape characters when they were reread and would end up printing one `\'. The correct way to obtain a printable backslash is to use the `\e' escape sequence: This always prints a single instance of the current escape character, regardless of whether or not it is used in a diversion; it also works in both GNU `troff' and UNIX `troff'.(1) (*note Implementation Differences-Footnote-1::) To store, for some reason, an escape sequence in a diversion that is interpreted when the diversion is reread, either use the traditional `\!' transparent output facility, or, if this is unsuitable, the new `\?' escape sequence. *Note Diversions::, and *note Gtroff Internals::, for more information. (1) To be completely independent of the current escape character, use `\(rs' which represents a reverse solidus (backslash) glyph. 6 Preprocessors *************** This chapter describes all preprocessors that come with `groff' or which are freely available. 6.1 `geqn' ========== 6.1.1 Invoking `geqn' --------------------- 6.2 `gtbl' ========== 6.2.1 Invoking `gtbl' --------------------- 6.3 `gpic' ========== 6.3.1 Invoking `gpic' --------------------- 6.4 `ggrn' ========== 6.4.1 Invoking `ggrn' --------------------- 6.5 `grap' ========== A free implementation of `grap', written by Ted Faber, is available as an extra package from the following address: `http://www.lunabase.org/~faber/Vault/software/grap/' 6.6 `gchem' =========== 6.6.1 Invoking `gchem' ---------------------- 6.7 `grefer' ============ 6.7.1 Invoking `grefer' ----------------------- 6.8 `gsoelim' ============= 6.8.1 Invoking `gsoelim' ------------------------ 6.9 `preconv' ============= 6.9.1 Invoking `preconv' ------------------------ 7 Output Devices **************** 7.1 Special Characters ====================== *Note Font Files::. 7.2 `grotty' ============ The postprocessor `grotty' translates the output from GNU `troff' into a form suitable for typewriter-like devices. It is fully documented on its manual page, `grotty(1)'. 7.2.1 Invoking `grotty' ----------------------- The postprocessor `grotty' accepts the following command-line options: `-b' Do not overstrike bold glyphs. Ignored if `-c' isn't used. `-B' Do not underline bold-italic glyphs. Ignored if `-c' isn't used. `-c' Use overprint and disable colours for printing on legacy Teletype printers (see below). `-d' Do not render lines (this is, ignore all `\D' escapes). `-f' Use form feed control characters in the output. `-FDIR' Put the directory `DIR/devNAME' in front of the search path for the font and device description files, given the target device NAME. `-h' Use horizontal tabs for sequences of 8 space characters. `-i' Request italic glyphs from the terminal. Ignored if `-c' is active. `-o' Do not overstrike. `-r' Highlight italic glyphs. Ignored if `-c' is active. `-u' Do not underline italic glyphs. Ignored if `-c' isn't used. `-U' Do not overstrike bold-italic glyphs. Ignored if `-c' isn't used. `-v' Print the version number. The `-c' mode for TTY output devices means that underlining is done by emitting sequences of `_' and `^H' (the backspace character) before the actual character. Literally, this is printing an underline character, then moving the caret back one character position, and printing the actual character at the same position as the underline character (similar to a typewriter). Usually, a modern terminal can't interpret this (and the original Teletype machines for which this sequence was appropriate are no longer in use). You need a pager program like `less' which translates this into ISO 6429 SGR sequences to control terminals. 7.3 `grops' =========== The postprocessor `grops' translates the output from GNU `troff' into a form suitable for Adobe POSTSCRIPT devices. It is fully documented on its manual page, `grops(1)'. 7.3.1 Invoking `grops' ---------------------- The postprocessor `grops' accepts the following command-line options: `-bFLAGS' Use backward compatibility settings given by FLAGS as documented in the `grops(1)' manual page. Overrides the command `broken' in the `DESC' file. `-cN' Print N copies of each page. `-FDIR' Put the directory `DIR/devNAME' in front of the search path for the font, prologue and device description files, given the target device NAME, usually *ps*. `-g' Tell the printer to guess the page length. Useful for printing vertically centered pages when the paper dimensions are determined at print time. `-IPATH ...' Consider the directory `PATH' for searching included files specified with relative paths. The current directory is searched as fallback. `-l' Use landscape orientation. `-m' Use manual feed. `-pPAPERSIZE' Set the page dimensions. Overrides the commands `papersize', `paperlength', and `paperwidth' in the `DESC' file. See the `groff_font(5)' manual page for details. `-PPROLOGUE' Use the PROLOGUE in the font path as the prologue instead of the default `prologue'. Overrides the environment variable `GROPS_PROLOGUE'. `-wN' Set the line thickness to N/1000em. Overrides the default value N = 40. `-v' Print the version number. 7.3.2 Embedding POSTSCRIPT -------------------------- The escape sequence `\X'ps: import FILE LLX LLY URX URY WIDTH [HEIGHT]'' places a rectangle of the specified WIDTH containing the POSTSCRIPT drawing from file FILE bound by the box from LLX LLY to URX URY (in POSTSCRIPT coordinates) at the insertion point. If HEIGHT is not specified, the embedded drawing is scaled proportionally. *Note Miscellaneous::, for the `psbb' request which automatically generates the bounding box. This escape sequence is used internally by the macro `PSPIC' (see the `groff_tmac(5)' manual page). 7.4 `gropdf' ============ The postprocessor `gropdf' translates the output from GNU `troff' into a form suitable for Adobe PDF devices. It is fully documented on its manual page, `gropdf(1)'. 7.4.1 Invoking `gropdf' ----------------------- The postprocessor `gropdf' accepts the following command-line options: `-d' Produce uncompressed PDFs which include debugging comments. `-e' This forces `gropdf' to embed all used fonts in the PDF, even if they are one of the 14 base Adobe fonts. `-FDIR' Put the directory `DIR/devNAME' in front of the search path for the font, prologue and device description files, given the target device NAME, usually *pdf*. `-yFOUNDRY' This forces the use of a different font foundry. `-l' Use landscape orientation. `-pPAPERSIZE' Set the page dimensions. Overrides the commands `papersize', `paperlength', and `paperwidth' in the `DESC' file. See the `groff_font(5)' manual page for details. `-v' Print the version number. `-s' Append a comment line to end of PDF showing statistics, i.e. number of pages in document. Ghostscript's `ps2pdf(1)' complains about this line if it is included, but works anyway. `-uFILENAME' `gropdf' normally includes a ToUnicode CMap with any font created using `text.enc' as the encoding file, this makes it easier to search for words which contain ligatures. You can include your own CMap by specifying a FILENAME or have no CMap at all by omitting the FILENAME. 7.4.2 Embedding PDF ------------------- The escape sequence `\X'pdf: pdfpic FILE ALIGNMENT WIDTH [HEIGHT] [LINELENGTH]'' places a rectangle of the specified WIDTH containing the PDF drawing from file FILE of desired WIDTH and HEIGHT (if HEIGHT is missing or zero then it is scaled proportionally). If ALIGNMENT is `-L' the drawing is left aligned. If it is `-C' or `-R' a LINELENGTH greater than the width of the drawing is required as well. If WIDTH is specified as zero then the width is scaled in proportion to the height. 7.5 `grodvi' ============ The postprocessor `grodvi' translates the output from GNU `troff' into the *DVI* output format compatible with the *TeX* document preparation system. It is fully documented on its manual page, `grodvi(1)'. 7.5.1 Invoking `grodvi' ----------------------- The postprocessor `grodvi' accepts the following command-line options: `-d' Do not use *tpic* specials to implement drawing commands. `-FDIR' Put the directory `DIR/devNAME' in front of the search path for the font and device description files, given the target device NAME, usually *dvi*. `-l' Use landscape orientation. `-pPAPERSIZE' Set the page dimensions. Overrides the commands `papersize', `paperlength', and `paperwidth' in the `DESC' file. See `groff_font(5)' manual page for details. `-v' Print the version number. `-wN' Set the line thickness to N/1000em. Overrides the default value N = 40. 7.6 `grolj4' ============ The postprocessor `grolj4' translates the output from GNU `troff' into the *PCL5* output format suitable for printing on a *HP LaserJet 4* printer. It is fully documented on its manual page, `grolj4(1)'. 7.6.1 Invoking `grolj4' ----------------------- The postprocessor `grolj4' accepts the following command-line options: `-cN' Print N copies of each page. `-FDIR' Put the directory `DIR/devNAME' in front of the search path for the font and device description files, given the target device NAME, usually *lj4*. `-l' Use landscape orientation. `-pSIZE' Set the page dimensions. Valid values for SIZE are: `letter', `legal', `executive', `a4', `com10', `monarch', `c5', `b5', `d1'. `-v' Print the version number. `-wN' Set the line thickness to N/1000em. Overrides the default value N = 40. The special drawing command `\D'R DH DV'' draws a horizontal rectangle from the current position to the position at offset (DH,DV). 7.7 `grolbp' ============ The postprocessor `grolbp' translates the output from GNU `troff' into the *LBP* output format suitable for printing on *Canon CAPSL* printers. It is fully documented on its manual page, `grolbp(1)'. 7.7.1 Invoking `grolbp' ----------------------- The postprocessor `grolbp' accepts the following command-line options: `-cN' Print N copies of each page. `-FDIR' Put the directory `DIR/devNAME' in front of the search path for the font, prologue and device description files, given the target device NAME, usually *lbp*. `-l' Use landscape orientation. `-oORIENTATION' Use the ORIENTATION specified: `portrait' or `landscape'. `-pPAPERSIZE' Set the page dimensions. See `groff_font(5)' manual page for details. `-wN' Set the line thickness to N/1000em. Overrides the default value N = 40. `-v' Print the version number. `-h' Print command-line help. 7.8 `grohtml' ============= The `grohtml' front end (which consists of a preprocessor, `pre-grohtml', and a device driver, `post-grohtml') translates the output of GNU `troff' to HTML. Users should always invoke `grohtml' via the `groff' command with a `\-Thtml' option. If no files are given, `grohtml' will read the standard input. A filename of `-' will also cause `grohtml' to read the standard input. HTML output is written to the standard output. When `grohtml' is run by `groff', options can be passed to `grohtml' using `groff''s `-P' option. `grohtml' invokes `groff' twice. In the first pass, pictures, equations, and tables are rendered using the `ps' device, and in the second pass HTML output is generated by the `html' device. `grohtml' always writes output in `UTF-8' encoding and has built-in entities for all non-composite unicode characters. In spite of this, `groff' may issue warnings about unknown special characters if they can't be found during the first pass. Such warnings can be safely ignored unless the special characters appear inside a table or equation, in which case glyphs for these characters must be defined for the `ps' device as well. This output device is fully documented on its manual page, `grohtml(1)'. 7.8.1 Invoking `grohtml' ------------------------ The postprocessor `grohtml' accepts the following command-line options: `-aBITS' Use this number of BITS (= 1, 2 or 4) for text antialiasing. Default: BITS = 4. `-a0' Do not use text antialiasing. `-b' Use white background. `-DDIR' Store rendered images in the directory `DIR'. `-FDIR' Put the directory `DIR/devNAME' in front of the search path for the font, prologue and device description files, given the target device NAME, usually *html*. `-gBITS' Use this number of BITS (= 1, 2 or 4) for antialiasing of drawings. Default: BITS = 4. `-g0' Do not use antialiasing for drawings. `-h' Use the `B' element for section headings. `-iRESOLUTION' Use the RESOLUTION for rendered images. Default: RESOLUTION = 100dpi. `-ISTEM' Set the images' STEM NAME. Default: STEM = `grohtml-XXX' (XXX is the process ID). `-jSTEM' Place each section in a separate file called `STEM-N.html' (where N is a generated section number). `-l' Do not generate the table of contents. `-n' Generate simple fragment identifiers. `-oOFFSET' Use vertical paddding OFFSET for images. `-p' Display the page rendering progress to `stderr'. `-r' Do not use horizontal rules to separate headers and footers. `-sSIZE' Set the base font size, to be modified using the elements `BIG' and `SMALL'. `-SLEVEL' Generate separate files for sections at level LEVEL. `-v' Print the version number. `-V' Generate a validator button at the bottom. `-y' Generate a signature of groff after the validator button, if any. 7.8.2 `grohtml' specific registers and strings ---------------------------------------------- -- Register: \n[ps4html] -- String: \*[www-image-template] The registers `ps4html' and `www-image-template' are defined by the `pre-grohtml' preprocessor. `pre-grohtml' reads in the `troff' input, marks up the inline equations and passes the result firstly to troff -Tps -rps4html=1 -dwww-image-template=TEMPLATE and secondly to troff -Thtml or troff -Txhtml The POSTSCRIPT device is used to create all the image files (for `-Thtml'; if `-Txhtml' is used, all equations are passed to `geqn' to produce MathML, and the register `ps4html' enables the macro sets to ignore floating keeps, footers, and headings. The register `www-image-template' is set to the user specified template name or the default name. 7.9 `gxditview' =============== 7.9.1 Invoking `gxditview' -------------------------- 8 File formats ************** All files read and written by `gtroff' are text files. The following two sections describe their format. 8.1 `gtroff' Output =================== This section describes the intermediate output format of GNU `troff'. This output is produced by a run of `gtroff' before it is fed into a device postprocessor program. As `groff' is a wrapper program around `gtroff' that automatically calls a postprocessor, this output does not show up normally. This is why it is called "intermediate". `groff' provides the option `-Z' to inhibit postprocessing, such that the produced intermediate output is sent to standard output just like calling `gtroff' manually. Here, the term "troff output" describes what is output by `gtroff', while "intermediate output" refers to the language that is accepted by the parser that prepares this output for the postprocessors. This parser is smarter on whitespace and implements obsolete elements for compatibility, otherwise both formats are the same.(1) (*note gtroff Output-Footnote-1::) The main purpose of the intermediate output concept is to facilitate the development of postprocessors by providing a common programming interface for all devices. It has a language of its own that is completely different from the `gtroff' language. While the `gtroff' language is a high-level programming language for text processing, the intermediate output language is a kind of low-level assembler language by specifying all positions on the page for writing and drawing. The intermediate output produced by `gtroff' is fairly readable, while output from AT&T `troff' is rather hard to understand because of strange habits that are still supported, but not used any longer by `gtroff'. (1) The parser and postprocessor for intermediate output can be found in the file `GROFF-SOURCE-DIR/src/libs/libdriver/input.cpp'. 8.1.1 Language Concepts ----------------------- During the run of `gtroff', the input data is cracked down to the information on what has to be printed at what position on the intended device. So the language of the intermediate output format can be quite small. Its only elements are commands with and without arguments. In this section, the term "command" always refers to the intermediate output language, and never to the `gtroff' language used for document formatting. There are commands for positioning and text writing, for drawing, and for device controlling. 8.1.1.1 Separation .................. AT&T `troff' output has strange requirements on whitespace. The `gtroff' output parser, however, is smart about whitespace by making it maximally optional. The whitespace characters, i.e., the tab, space, and newline characters, always have a syntactical meaning. They are never printable because spacing within the output is always done by positioning commands. Any sequence of space or tab characters is treated as a single "syntactical space". It separates commands and arguments, but is only required when there would occur a clashing between the command code and the arguments without the space. Most often, this happens when variable-length command names, arguments, argument lists, or command clusters meet. Commands and arguments with a known, fixed length need not be separated by syntactical space. A line break is a syntactical element, too. Every command argument can be followed by whitespace, a comment, or a newline character. Thus a "syntactical line break" is defined to consist of optional syntactical space that is optionally followed by a comment, and a newline character. The normal commands, those for positioning and text, consist of a single letter taking a fixed number of arguments. For historical reasons, the parser allows to stack such commands on the same line, but fortunately, in `gtroff''s intermediate output, every command with at least one argument is followed by a line break, thus providing excellent readability. The other commands - those for drawing and device controlling - have a more complicated structure; some recognize long command names, and some take a variable number of arguments. So all `D' and `x' commands were designed to request a syntactical line break after their last argument. Only one command, `x X', has an argument that can stretch over several lines; all other commands must have all of their arguments on the same line as the command, i.e., the arguments may not be split by a line break. Empty lines (these are lines containing only space and/or a comment), can occur everywhere. They are just ignored. 8.1.1.2 Argument Units ...................... Some commands take integer arguments that are assumed to represent values in a measurement unit, but the letter for the corresponding scale indicator is not written with the output command arguments. Most commands assume the scale indicator `u', the basic unit of the device, some use `z', the scaled point unit of the device, while others, such as the color commands, expect plain integers. Note that single characters can have the eighth bit set, as can the names of fonts and special characters. The names of characters and fonts can be of arbitrary length. A character that is to be printed is always in the current font. A string argument is always terminated by the next whitespace character (space, tab, or newline); an embedded `#' character is regarded as part of the argument, not as the beginning of a comment command. An integer argument is already terminated by the next non-digit character, which then is regarded as the first character of the next argument or command. 8.1.1.3 Document Parts ...................... A correct intermediate output document consists of two parts, the "prologue" and the "body". The task of the prologue is to set the general device parameters using three exactly specified commands. `gtroff''s prologue is guaranteed to consist of the following three lines (in that order): x T DEVICE x res N H V x init with the arguments set as outlined in *note Device Control Commands::. Note that the parser for the intermediate output format is able to swallow additional whitespace and comments as well even in the prologue. The body is the main section for processing the document data. Syntactically, it is a sequence of any commands different from the ones used in the prologue. Processing is terminated as soon as the first `x stop' command is encountered; the last line of any `gtroff' intermediate output always contains such a command. Semantically, the body is page oriented. A new page is started by a `p' command. Positioning, writing, and drawing commands are always done within the current page, so they cannot occur before the first `p' command. Absolute positioning (by the `H' and `V' commands) is done relative to the current page; all other positioning is done relative to the current location within this page. 8.1.2 Command Reference ----------------------- This section describes all intermediate output commands, both from AT&T `troff' as well as the `gtroff' extensions. 8.1.2.1 Comment Command ....................... `#ANYTHING' A comment. Ignore any characters from the `#' character up to the next newline character. This command is the only possibility for commenting in the intermediate output. Each comment can be preceded by arbitrary syntactical space; every command can be terminated by a comment. 8.1.2.2 Simple Commands ....................... The commands in this subsection have a command code consisting of a single character, taking a fixed number of arguments. Most of them are commands for positioning and text writing. These commands are smart about whitespace. Optionally, syntactical space can be inserted before, after, and between the command letter and its arguments. All of these commands are stackable, i.e., they can be preceded by other simple commands or followed by arbitrary other commands on the same line. A separating syntactical space is only necessary when two integer arguments would clash or if the preceding argument ends with a string argument. `C XXX' Print a special character named XXX. The trailing syntactical space or line break is necessary to allow glyph names of arbitrary length. The glyph is printed at the current print position; the glyph's size is read from the font file. The print position is not changed. `c G' Print glyph G at the current print position;(1) (*note Simple Commands-Footnote-1::) the glyph's size is read from the font file. The print position is not changed. `f N' Set font to font number N (a non-negative integer). `H N' Move right to the absolute vertical position N (a non-negative integer in basic units `u' relative to left edge of current page. `h N' Move N (a non-negative integer) basic units `u' horizontally to the right. The original UNIX troff manual allows negative values for N also, but `gtroff' doesn't use this. `m COLOR-SCHEME [COMPONENT ...]' Set the color for text (glyphs), line drawing, and the outline of graphic objects using different color schemes; the analoguous command for the filling color of graphic objects is `DF'. The color components are specified as integer arguments between 0 and 65536. The number of color components and their meaning vary for the different color schemes. These commands are generated by `gtroff''s escape sequence `\m'. No position changing. These commands are a `gtroff' extension. `mc CYAN MAGENTA YELLOW' Set color using the CMY color scheme, having the 3 color components CYAN, MAGENTA, and YELLOW. `md' Set color to the default color value (black in most cases). No component arguments. `mg GRAY' Set color to the shade of gray given by the argument, an integer between 0 (black) and 65536 (white). `mk CYAN MAGENTA YELLOW BLACK' Set color using the CMYK color scheme, having the 4 color components CYAN, MAGENTA, YELLOW, and BLACK. `mr RED GREEN BLUE' Set color using the RGB color scheme, having the 3 color components RED, GREEN, and BLUE. `N N' Print glyph with index N (a non-negative integer) of the current font. This command is a `gtroff' extension. `n B A' Inform the device about a line break, but no positioning is done by this command. In AT&T `troff', the integer arguments B and A informed about the space before and after the current line to make the intermediate output more human readable without performing any action. In `groff', they are just ignored, but they must be provided for compatibility reasons. `p N' Begin a new page in the outprint. The page number is set to N. This page is completely independent of pages formerly processed even if those have the same page number. The vertical position on the outprint is automatically set to 0. All positioning, writing, and drawing is always done relative to a page, so a `p' command must be issued before any of these commands. `s N' Set point size to N scaled points (this is unit `z'). AT&T `troff' used the unit points (`p') instead. *Note Output Language Compatibility::. `t XXX' `t XXX DUMMY-ARG' Print a word, i.e., a sequence of characters XXX representing output glyphs which names are single characters, terminated by a space character or a line break; an optional second integer argument is ignored (this allows the formatter to generate an even number of arguments). The first glyph should be printed at the current position, the current horizontal position should then be increased by the width of the first glyph, and so on for each glyph. The widths of the glyphs are read from the font file, scaled for the current point size, and rounded to a multiple of the horizontal resolution. Special characters cannot be printed using this command (use the `C' command for special characters). This command is a `gtroff' extension; it is only used for devices whose `DESC' file contains the `tcommand' keyword (*note DESC File Format::). `u N XXX' Print word with track kerning. This is the same as the `t' command except that after printing each glyph, the current horizontal position is increased by the sum of the width of that glyph and N (an integer in basic units `u'). This command is a `gtroff' extension; it is only used for devices whose `DESC' file contains the `tcommand' keyword (*note DESC File Format::). `V N' Move down to the absolute vertical position N (a non-negative integer in basic units `u') relative to upper edge of current page. `v N' Move N basic units `u' down (N is a non-negative integer). The original UNIX troff manual allows negative values for N also, but `gtroff' doesn't use this. `w' Informs about a paddable white space to increase readability. The spacing itself must be performed explicitly by a move command. (1) `c' is actually a misnomer since it outputs a glyph. 8.1.2.3 Graphics Commands ......................... Each graphics or drawing command in the intermediate output starts with the letter `D', followed by one or two characters that specify a subcommand; this is followed by a fixed or variable number of integer arguments that are separated by a single space character. A `D' command may not be followed by another command on the same line (apart from a comment), so each `D' command is terminated by a syntactical line break. `gtroff' output follows the classical spacing rules (no space between command and subcommand, all arguments are preceded by a single space character), but the parser allows optional space between the command letters and makes the space before the first argument optional. As usual, each space can be any sequence of tab and space characters. Some graphics commands can take a variable number of arguments. In this case, they are integers representing a size measured in basic units `u'. The arguments called H1, H2, ..., HN stand for horizontal distances where positive means right, negative left. The arguments called V1, V2, ..., VN stand for vertical distances where positive means down, negative up. All these distances are offsets relative to the current location. Each graphics command directly corresponds to a similar `gtroff' `\D' escape sequence. *Note Drawing Requests::. Unknown `D' commands are assumed to be device-specific. Its arguments are parsed as strings; the whole information is then sent to the postprocessor. In the following command reference, the syntax element means a syntactical line break as defined above. `D~ H1 V1 H2 V2 ... HN VN' Draw B-spline from current position to offset (H1,V1), then to offset (H2,V2), if given, etc. up to (HN,VN). This command takes a variable number of argument pairs; the current position is moved to the terminal point of the drawn curve. `Da H1 V1 H2 V2' Draw arc from current position to (H1,V1)+(H2,V2) with center at (H1,V1); then move the current position to the final point of the arc. `DC D' `DC D DUMMY-ARG' Draw a solid circle using the current fill color with diameter D (integer in basic units `u') with leftmost point at the current position; then move the current position to the rightmost point of the circle. An optional second integer argument is ignored (this allows the formatter to generate an even number of arguments). This command is a `gtroff' extension. `Dc D' Draw circle line with diameter D (integer in basic units `u') with leftmost point at the current position; then move the current position to the rightmost point of the circle. `DE H V' Draw a solid ellipse in the current fill color with a horizontal diameter of H and a vertical diameter of V (both integers in basic units `u') with the leftmost point at the current position; then move to the rightmost point of the ellipse. This command is a `gtroff' extension. `De H V' Draw an outlined ellipse with a horizontal diameter of H and a vertical diameter of V (both integers in basic units `u') with the leftmost point at current position; then move to the rightmost point of the ellipse. `DF COLOR-SCHEME [COMPONENT ...]' Set fill color for solid drawing objects using different color schemes; the analoguous command for setting the color of text, line graphics, and the outline of graphic objects is `m'. The color components are specified as integer arguments between 0 and 65536. The number of color components and their meaning vary for the different color schemes. These commands are generated by `gtroff''s escape sequences `\D'F ...'' and `\M' (with no other corresponding graphics commands). No position changing. This command is a `gtroff' extension. `DFc CYAN MAGENTA YELLOW' Set fill color for solid drawing objects using the CMY color scheme, having the 3 color components CYAN, MAGENTA, and YELLOW. `DFd' Set fill color for solid drawing objects to the default fill color value (black in most cases). No component arguments. `DFg GRAY' Set fill color for solid drawing objects to the shade of gray given by the argument, an integer between 0 (black) and 65536 (white). `DFk CYAN MAGENTA YELLOW BLACK' Set fill color for solid drawing objects using the CMYK color scheme, having the 4 color components CYAN, MAGENTA, YELLOW, and BLACK. `DFr RED GREEN BLUE' Set fill color for solid drawing objects using the RGB color scheme, having the 3 color components RED, GREEN, and BLUE. `Df N' The argument N must be an integer in the range -32767 to 32767. 0 <= N <= 1000 Set the color for filling solid drawing objects to a shade of gray, where 0 corresponds to solid white, 1000 (the default) to solid black, and values in between to intermediate shades of gray; this is obsoleted by command `DFg'. N < 0 or N > 1000 Set the filling color to the color that is currently being used for the text and the outline, see command `m'. For example, the command sequence mg 0 0 65536 Df -1 sets all colors to blue. No position changing. This command is a `gtroff' extension. `Dl H V' Draw line from current position to offset (H,V) (integers in basic units `u'); then set current position to the end of the drawn line. `Dp H1 V1 H2 V2 ... HN VN' Draw a polygon line from current position to offset (H1,V1), from there to offset (H2,V2), etc. up to offset (HN,VN), and from there back to the starting position. For historical reasons, the position is changed by adding the sum of all arguments with odd index to the actual horizontal position and the even ones to the vertical position. Although this doesn't make sense it is kept for compatibility. This command is a `gtroff' extension. `Dp H1 V1 H2 V2 ... HN VN' Draw a solid polygon in the current fill color rather than an outlined polygon, using the same arguments and positioning as the corresponding `Dp' command. This command is a `gtroff' extension. `Dt N' Set the current line thickness to N (an integer in basic units `u') if N>0; if N=0 select the smallest available line thickness; if N<0 set the line thickness proportional to the point size (this is the default before the first `Dt' command was specified). For historical reasons, the horizontal position is changed by adding the argument to the actual horizontal position, while the vertical position is not changed. Although this doesn't make sense it is kept for compatibility. This command is a `gtroff' extension. 8.1.2.4 Device Control Commands ............................... Each device control command starts with the letter `x', followed by a space character (optional or arbitrary space or tab in `gtroff') and a subcommand letter or word; each argument (if any) must be preceded by a syntactical space. All `x' commands are terminated by a syntactical line break; no device control command can be followed by another command on the same line (except a comment). The subcommand is basically a single letter, but to increase readability, it can be written as a word, i.e., an arbitrary sequence of characters terminated by the next tab, space, or newline character. All characters of the subcommand word but the first are simply ignored. For example, `gtroff' outputs the initialization command `x i' as `x init' and the resolution command `x r' as `x res'. In the following, the syntax element means a syntactical line break (*note Separation::). `xF NAME' The `F' stands for FILENAME. Use NAME as the intended name for the current file in error reports. This is useful for remembering the original file name when `gtroff' uses an internal piping mechanism. The input file is not changed by this command. This command is a `gtroff' extension. `xf N S' The `f' stands for FONT. Mount font position N (a non-negative integer) with font named S (a text word). *Note Font Positions::. `xH N' The `H' stands for HEIGHT. Set glyph height to N (a positive integer in scaled points `z'). AT&T `troff' uses the unit points (`p') instead. *Note Output Language Compatibility::. `xi' The `i' stands for INIT. Initialize device. This is the third command of the prologue. `xp' The `p' stands for PAUSE. Parsed but ignored. The original UNIX troff manual writes pause device, can be restarted `xr N H V' The `r' stands for RESOLUTION. Resolution is N, while H is the minimal horizontal motion, and V the minimal vertical motion possible with this device; all arguments are positive integers in basic units `u' per inch. This is the second command of the prologue. `xS N' The `S' stands for SLANT. Set slant to N (an integer in basic units `u'). `xs' The `s' stands for STOP. Terminates the processing of the current file; issued as the last command of any intermediate troff output. `xt' The `t' stands for TRAILER. Generate trailer information, if any. In GTROFF, this is actually just ignored. `xT XXX' The `T' stands for TYPESETTER. Set name of device to word XXX, a sequence of characters ended by the next white space character. The possible device names coincide with those from the `groff' `-T' option. This is the first command of the prologue. `xu N' The `u' stands for UNDERLINE. Configure underlining of spaces. If N is 1, start underlining of spaces; if N is 0, stop underlining of spaces. This is needed for the `cu' request in nroff mode and is ignored otherwise. This command is a `gtroff' extension. `xX ANYTHING' The `x' stands for X-ESCAPE. Send string ANYTHING uninterpreted to the device. If the line following this command starts with a `+' character this line is interpreted as a continuation line in the following sense. The `+' is ignored, but a newline character is sent instead to the device, the rest of the line is sent uninterpreted. The same applies to all following lines until the first character of a line is not a `+' character. This command is generated by the `gtroff' escape sequence `\X'. The line-continuing feature is a `gtroff' extension. 8.1.2.5 Obsolete Command ........................ In AT&T `troff' output, the writing of a single glyph is mostly done by a very strange command that combines a horizontal move and a single character giving the glyph name. It doesn't have a command code, but is represented by a 3-character argument consisting of exactly 2 digits and a character. DDG Move right DD (exactly two decimal digits) basic units `u', then print glyph G (represented as a single character). In `gtroff', arbitrary syntactical space around and within this command is allowed to be added. Only when a preceding command on the same line ends with an argument of variable length a separating space is obligatory. In AT&T `troff', large clusters of these and other commands are used, mostly without spaces; this made such output almost unreadable. For modern high-resolution devices, this command does not make sense because the width of the glyphs can become much larger than two decimal digits. In `gtroff', this is only used for the devices `X75', `X75-12', `X100', and `X100-12'. For other devices, the commands `t' and `u' provide a better functionality. 8.1.3 Intermediate Output Examples ---------------------------------- This section presents the intermediate output generated from the same input for three different devices. The input is the sentence `hell world' fed into `gtroff' on the command line. High-resolution device `ps' This is the standard output of `gtroff' if no `-T' option is given. shell> echo "hell world" | groff -Z -T ps x T ps x res 72000 1 1 x init p1 x font 5 TR f5 s10000 V12000 H72000 thell wh2500 tw H96620 torld n12000 0 x trailer V792000 x stop This output can be fed into `grops' to get its representation as a POSTSCRIPT file. Low-resolution device `latin1' This is similar to the high-resolution device except that the positioning is done at a minor scale. Some comments (lines starting with `#') were added for clarification; they were not generated by the formatter. shell> echo "hell world" | groff -Z -T latin1 # prologue x T latin1 x res 240 24 40 x init # begin a new page p1 # font setup x font 1 R f1 s10 # initial positioning on the page V40 H0 # write text `hell' thell # inform about space, and issue a horizontal jump wh24 # write text `world' tworld # announce line break, but do nothing because ... n40 0 # ... the end of the document has been reached x trailer V2640 x stop This output can be fed into `grotty' to get a formatted text document. AT&T `troff' output Since a computer monitor has a very low resolution compared to modern printers the intermediate output for the X Window devices can use the jump-and-write command with its 2-digit displacements. shell> echo "hell world" | groff -Z -T X100 x T X100 x res 100 1 1 x init p1 x font 5 TR f5 s10 V16 H100 # write text with jump-and-write commands ch07e07l03lw06w11o07r05l03dh7 n16 0 x trailer V1100 x stop This output can be fed into `xditview' or `gxditview' for displaying in X. Due to the obsolete jump-and-write command, the text clusters in the AT&T `troff' output are almost unreadable. 8.1.4 Output Language Compatibility ----------------------------------- The intermediate output language of AT&T `troff' was first documented in the UNIX troff manual, with later additions documented in `A Typesetter-indenpendent TROFF', written by Brian Kernighan. The `gtroff' intermediate output format is compatible with this specification except for the following features. * The classical quasi device independence is not yet implemented. * The old hardware was very different from what we use today. So the `groff' devices are also fundamentally different from the ones in AT&T `troff'. For example, the AT&T POSTSCRIPT device is called `post' and has a resolution of only 720 units per inch, suitable for printers 20 years ago, while `groff''s `ps' device has a resolution of 72000 units per inch. Maybe, by implementing some rescaling mechanism similar to the classical quasi device independence, `groff' could emulate AT&T's `post' device. * The B-spline command `D~' is correctly handled by the intermediate output parser, but the drawing routines aren't implemented in some of the postprocessor programs. * The argument of the commands `s' and `x H' has the implicit unit scaled point `z' in `gtroff', while AT&T `troff' has point (`p'). This isn't an incompatibility but a compatible extension, for both units coincide for all devices without a `sizescale' parameter in the `DESC' file, including all postprocessors from AT&T and `groff''s text devices. The few `groff' devices with a `sizescale' parameter either do not exist for AT&T `troff', have a different name, or seem to have a different resolution. So conflicts are very unlikely. * The position changing after the commands `Dp', `DP', and `Dt' is illogical, but as old versions of `gtroff' used this feature it is kept for compatibility reasons. 8.2 Font Files ============== The `gtroff' font format is roughly a superset of the `ditroff' font format (as used in later versions of AT&T `troff' and its descendants). Unlike the `ditroff' font format, there is no associated binary format; all files are text files.(1) (*note Font Files-Footnote-1::) The font files for device NAME are stored in a directory `devNAME'. There are two types of file: a device description file called `DESC' and for each font F a font file called `F'. (1) Plan 9 `troff' has also abandoned the binary format. 8.2.1 `DESC' File Format ------------------------ The `DESC' file can contain the following types of line. Except for the `charset' keyword which must comes last (if at all), the order of the lines is not important. Later entries in the file, however, override previous values. `charset' This line and everything following in the file are ignored. It is allowed for the sake of backwards compatibility. `family FAM' The default font family is FAM. `fonts N F1 F2 F3 ... FN' Fonts F1 ... FN are mounted in the font positions M+1, ..., M+N where M is the number of styles. This command may extend over more than one line. A font name of 0 means no font is mounted on the corresponding font position. `hor N' The horizontal resolution is N machine units. All horizontal quantities are rounded to be multiples of this value. `image_generator STRING' Needed for `grohtml' only. It specifies the program to generate PNG images from POSTSCRIPT input. Under GNU/Linux this is usually `gs' but under other systems (notably cygwin) it might be set to another name. `paperlength N' The physical vertical dimension of the output medium in machine units. This isn't used by `troff' itself but by output devices. Deprecated. Use `papersize' instead. `papersize STRING ...' Select a paper size. Valid values for STRING are the ISO paper types `A0'-`A7', `B0'-`B7', `C0'-`C7', `D0'-`D7', `DL', and the US paper types `letter', `legal', `tabloid', `ledger', `statement', `executive', `com10', and `monarch'. Case is not significant for STRING if it holds predefined paper types. Alternatively, STRING can be a file name (e.g. `/etc/papersize'); if the file can be opened, `groff' reads the first line and tests for the above paper sizes. Finally, STRING can be a custom paper size in the format `LENGTH,WIDTH' (no spaces before and after the comma). Both LENGTH and WIDTH must have a unit appended; valid values are `i' for inches, `C' for centimeters, `p' for points, and `P' for picas. Example: `12c,235p'. An argument which starts with a digit is always treated as a custom paper format. `papersize' sets both the vertical and horizontal dimension of the output medium. More than one argument can be specified; `groff' scans from left to right and uses the first valid paper specification. `paperwidth N' The physical horizontal dimension of the output medium in machine units. This isn't used by `troff' itself but by output devices. Deprecated. Use `papersize' instead. `pass_filenames' Tell `gtroff' to emit the name of the source file currently being processed. This is achieved by the intermediate output command `F'. Currently, this is only used by the `grohtml' output device. `postpro PROGRAM' Call PROGRAM as a postprocessor. For example, the line postpro grodvi in the file `devdvi/DESC' makes `groff' call `grodvi' if option `-Tdvi' is given (and `-Z' isn't used). `prepro PROGRAM' Call PROGRAM as a preprocessor. Currently, this keyword is used by `groff' with option `-Thtml' or `-Txhtml' only. `print PROGRAM' Use PROGRAM as a spooler program for printing. If omitted, the `-l' and `-L' options of `groff' are ignored. `res N' There are N machine units per inch. `sizes S1 S2 ... SN 0' This means that the device has fonts at S1, S2, ... SN scaled points. The list of sizes must be terminated by 0 (this is digit zero). Each SI can also be a range of sizes M-N. The list can extend over more than one line. `sizescale N' The scale factor for point sizes. By default this has a value of 1. One scaled point is equal to one point/N. The arguments to the `unitwidth' and `sizes' commands are given in scaled points. *Note Fractional Type Sizes::, for more information. `styles S1 S2 ... SM' The first M font positions are associated with styles S1 ... SM. `tcommand' This means that the postprocessor can handle the `t' and `u' intermediate output commands. `unicode' Indicate that the output device supports the complete Unicode repertoire. Useful only for devices which produce _character entities_ instead of glyphs. If `unicode' is present, no `charset' section is required in the font description files since the Unicode handling built into `groff' is used. However, if there are entries in a `charset' section, they either override the default mappings for those particular characters or add new mappings (normally for composite characters). This is used for `-Tutf8', `-Thtml', and `-Txhtml'. `unitwidth N' Quantities in the font files are given in machine units for fonts whose point size is N scaled points. `unscaled_charwidths' Make the font handling module always return unscaled character widths. Needed for the `grohtml' device. `use_charnames_in_special' This command indicates that `gtroff' should encode special characters inside special commands. Currently, this is only used by the `grohtml' output device. *Note Postprocessor Access::. `vert N' The vertical resolution is N machine units. All vertical quantities are rounded to be multiples of this value. The `res', `unitwidth', `fonts', and `sizes' lines are mandatory. Other commands are ignored by `gtroff' but may be used by postprocessors to store arbitrary information about the device in the `DESC' file. Here a list of obsolete keywords which are recognized by `groff' but completely ignored: `spare1', `spare2', `biggestfont'. 8.2.2 Font File Format ---------------------- A "font file", also (and probably better) called a "font description file", has two sections. The first section is a sequence of lines each containing a sequence of blank delimited words; the first word in the line is a key, and subsequent words give a value for that key. `name F' The name of the font is F. `spacewidth N' The normal width of a space is N. `slant N' The glyphs of the font have a slant of N degrees. (Positive means forward.) `ligatures LIG1 LIG2 ... LIGN [0]' Glyphs LIG1, LIG2, ..., LIGN are ligatures; possible ligatures are `ff', `fi', `fl', `ffi' and `ffl'. For backwards compatibility, the list of ligatures may be terminated with a 0. The list of ligatures may not extend over more than one line. `special' The font is "special"; this means that when a glyph is requested that is not present in the current font, it is searched for in any special fonts that are mounted. Other commands are ignored by `gtroff' but may be used by postprocessors to store arbitrary information about the font in the font file. The first section can contain comments which start with the `#' character and extend to the end of a line. The second section contains one or two subsections. It must contain a `charset' subsection and it may also contain a `kernpairs' subsection. These subsections can appear in any order. Each subsection starts with a word on a line by itself. The word `charset' starts the character set subsection.(1) (*note Font File Format-Footnote-1::) The `charset' line is followed by a sequence of lines. Each line gives information for one glyph. A line comprises a number of fields separated by blanks or tabs. The format is NAME METRICS TYPE CODE [ENTITY-NAME] [`--' COMMENT] NAME identifies the glyph name(2) (*note Font File Format-Footnote-2::): If NAME is a single character C then it corresponds to the `gtroff' input character C; if it is of the form `\C' where C is a single character, then it corresponds to the special character `\[C]'; otherwise it corresponds to the special character `\[NAME]'. If it is exactly two characters XX it can be entered as `\(XX'. Note that single-letter special characters can't be accessed as `\C'; the only exception is `\-' which is identical to `\[-]'. `gtroff' supports 8-bit input characters; however some utilities have difficulties with eight-bit characters. For this reason, there is a convention that the entity name `charN' is equivalent to the single input character whose code is N. For example, `char163' would be equivalent to the character with code 163 which is the pounds sterling sign in the ISO Latin-1 character set. You shouldn't use `charN' entities in font description files since they are related to input, not output. Otherwise, you get hard-coded connections between input and output encoding which prevents use of different (input) character sets. The name `---' is special and indicates that the glyph is unnamed; such glyphs can only be used by means of the `\N' escape sequence in `gtroff'. The TYPE field gives the glyph type: `1' the glyph has a descender, for example, `p'; `2' the glyph has an ascender, for example, `b'; `3' the glyph has both an ascender and a descender, for example, `('. The CODE field gives the code which the postprocessor uses to print the glyph. The glyph can also be input to `gtroff' using this code by means of the `\N' escape sequence. CODE can be any integer. If it starts with `0' it is interpreted as octal; if it starts with `0x' or `0X' it is interpreted as hexadecimal. Note, however, that the `\N' escape sequence only accepts a decimal integer. The ENTITY-NAME field gives an ASCII string identifying the glyph which the postprocessor uses to print the `gtroff' glyph NAME. This field is optional and has been introduced so that the `grohtml' device driver can encode its character set. For example, the glyph `\[Po]' is represented as `£' in HTML 4.0. Anything on the line after the ENTITY-NAME field resp. after `--' is ignored. The METRICS field has the form: WIDTH[`,'HEIGHT[`,'DEPTH[`,'ITALIC-CORRECTION [`,'LEFT-ITALIC-CORRECTION[`,'SUBSCRIPT-CORRECTION]]]]] There must not be any spaces between these subfields (it has been split here into two lines for better legibility only). Missing subfields are assumed to be 0. The subfields are all decimal integers. Since there is no associated binary format, these values are not required to fit into a variable of type `char' as they are in `ditroff'. The WIDTH subfield gives the width of the glyph. The HEIGHT subfield gives the height of the glyph (upwards is positive); if a glyph does not extend above the baseline, it should be given a zero height, rather than a negative height. The DEPTH subfield gives the depth of the glyph, that is, the distance from the baseline to the lowest point below the baseline to which the glyph extends (downwards is positive); if a glyph does not extend below the baseline, it should be given a zero depth, rather than a negative depth. The ITALIC-CORRECTION subfield gives the amount of space that should be added after the glyph when it is immediately to be followed by a glyph from a roman font. The LEFT-ITALIC-CORRECTION subfield gives the amount of space that should be added before the glyph when it is immediately to be preceded by a glyph from a roman font. The SUBSCRIPT-CORRECTION gives the amount of space that should be added after a glyph before adding a subscript. This should be less than the italic correction. A line in the `charset' section can also have the format NAME " This indicates that NAME is just another name for the glyph mentioned in the preceding line. The word `kernpairs' starts the kernpairs section. This contains a sequence of lines of the form: C1 C2 N This means that when glyph C1 appears next to glyph C2 the space between them should be increased by N. Most entries in the kernpairs section have a negative value for N. (1) This keyword is misnamed since it starts a list of ordered glyphs, not characters. (2) The distinction between input, characters, and output, glyphs, is not clearly separated in the terminology of `groff'; for example, the `char' request should be called `glyph' since it defines an output entity. 9 Installation ************** Appendix A Copying This Manual ****************************** Version 1.3, 3 November 2008 Copyright (C) 2000, 2001, 2002, 2007, 2008 Free Software Foundation, Inc. `http://fsf.org/' Everyone is permitted to copy and distribute verbatim copies of this license document, but changing it is not allowed. 0. PREAMBLE The purpose of this License is to make a manual, textbook, or other functional and useful document "free" in the sense of freedom: to assure everyone the effective freedom to copy and redistribute it, with or without modifying it, either commercially or noncommercially. Secondarily, this License preserves for the author and publisher a way to get credit for their work, while not being considered responsible for modifications made by others. This License is a kind of "copyleft", which means that derivative works of the document must themselves be free in the same sense. It complements the GNU General Public License, which is a copyleft license designed for free software. We have designed this License in order to use it for manuals for free software, because free software needs free documentation: a free program should come with manuals providing the same freedoms that the software does. But this License is not limited to software manuals; it can be used for any textual work, regardless of subject matter or whether it is published as a printed book. We recommend this License principally for works whose purpose is instruction or reference. 1. APPLICABILITY AND DEFINITIONS This License applies to any manual or other work, in any medium, that contains a notice placed by the copyright holder saying it can be distributed under the terms of this License. Such a notice grants a world-wide, royalty-free license, unlimited in duration, to use that work under the conditions stated herein. The "Document", below, refers to any such manual or work. Any member of the public is a licensee, and is addressed as "you". You accept the license if you copy, modify or distribute the work in a way requiring permission under copyright law. A "Modified Version" of the Document means any work containing the Document or a portion of it, either copied verbatim, or with modifications and/or translated into another language. A "Secondary Section" is a named appendix or a front-matter section of the Document that deals exclusively with the relationship of the publishers or authors of the Document to the Document's overall subject (or to related matters) and contains nothing that could fall directly within that overall subject. (Thus, if the Document is in part a textbook of mathematics, a Secondary Section may not explain any mathematics.) The relationship could be a matter of historical connection with the subject or with related matters, or of legal, commercial, philosophical, ethical or political position regarding them. The "Invariant Sections" are certain Secondary Sections whose titles are designated, as being those of Invariant Sections, in the notice that says that the Document is released under this License. If a section does not fit the above definition of Secondary then it is not allowed to be designated as Invariant. The Document may contain zero Invariant Sections. If the Document does not identify any Invariant Sections then there are none. The "Cover Texts" are certain short passages of text that are listed, as Front-Cover Texts or Back-Cover Texts, in the notice that says that the Document is released under this License. A Front-Cover Text may be at most 5 words, and a Back-Cover Text may be at most 25 words. A "Transparent" copy of the Document means a machine-readable copy, represented in a format whose specification is available to the general public, that is suitable for revising the document straightforwardly with generic text editors or (for images composed of pixels) generic paint programs or (for drawings) some widely available drawing editor, and that is suitable for input to text formatters or for automatic translation to a variety of formats suitable for input to text formatters. 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List on the Title Page, as authors, one or more persons or entities responsible for authorship of the modifications in the Modified Version, together with at least five of the principal authors of the Document (all of its principal authors, if it has fewer than five), unless they release you from this requirement. C. State on the Title page the name of the publisher of the Modified Version, as the publisher. D. Preserve all the copyright notices of the Document. E. Add an appropriate copyright notice for your modifications adjacent to the other copyright notices. F. Include, immediately after the copyright notices, a license notice giving the public permission to use the Modified Version under the terms of this License, in the form shown in the Addendum below. G. Preserve in that license notice the full lists of Invariant Sections and required Cover Texts given in the Document's license notice. H. Include an unaltered copy of this License. I. Preserve the section Entitled "History", Preserve its Title, and add to it an item stating at least the title, year, new authors, and publisher of the Modified Version as given on the Title Page. If there is no section Entitled "History" in the Document, create one stating the title, year, authors, and publisher of the Document as given on its Title Page, then add an item describing the Modified Version as stated in the previous sentence. J. Preserve the network location, if any, given in the Document for public access to a Transparent copy of the Document, and likewise the network locations given in the Document for previous versions it was based on. These may be placed in the "History" section. You may omit a network location for a work that was published at least four years before the Document itself, or if the original publisher of the version it refers to gives permission. K. For any section Entitled "Acknowledgements" or "Dedications", Preserve the Title of the section, and preserve in the section all the substance and tone of each of the contributor acknowledgements and/or dedications given therein. L. Preserve all the Invariant Sections of the Document, unaltered in their text and in their titles. Section numbers or the equivalent are not considered part of the section titles. M. Delete any section Entitled "Endorsements". Such a section may not be included in the Modified Version. N. Do not retitle any existing section to be Entitled "Endorsements" or to conflict in title with any Invariant Section. O. Preserve any Warranty Disclaimers. If the Modified Version includes new front-matter sections or appendices that qualify as Secondary Sections and contain no material copied from the Document, you may at your option designate some or all of these sections as invariant. To do this, add their titles to the list of Invariant Sections in the Modified Version's license notice. These titles must be distinct from any other section titles. You may add a section Entitled "Endorsements", provided it contains nothing but endorsements of your Modified Version by various parties--for example, statements of peer review or that the text has been approved by an organization as the authoritative definition of a standard. You may add a passage of up to five words as a Front-Cover Text, and a passage of up to 25 words as a Back-Cover Text, to the end of the list of Cover Texts in the Modified Version. Only one passage of Front-Cover Text and one of Back-Cover Text may be added by (or through arrangements made by) any one entity. If the Document already includes a cover text for the same cover, previously added by you or by arrangement made by the same entity you are acting on behalf of, you may not add another; but you may replace the old one, on explicit permission from the previous publisher that added the old one. The author(s) and publisher(s) of the Document do not by this License give permission to use their names for publicity for or to assert or imply endorsement of any Modified Version. 5. COMBINING DOCUMENTS You may combine the Document with other documents released under this License, under the terms defined in section 4 above for modified versions, provided that you include in the combination all of the Invariant Sections of all of the original documents, unmodified, and list them all as Invariant Sections of your combined work in its license notice, and that you preserve all their Warranty Disclaimers. 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TRANSLATION Translation is considered a kind of modification, so you may distribute translations of the Document under the terms of section 4. Replacing Invariant Sections with translations requires special permission from their copyright holders, but you may include translations of some or all Invariant Sections in addition to the original versions of these Invariant Sections. You may include a translation of this License, and all the license notices in the Document, and any Warranty Disclaimers, provided that you also include the original English version of this License and the original versions of those notices and disclaimers. In case of a disagreement between the translation and the original version of this License or a notice or disclaimer, the original version will prevail. If a section in the Document is Entitled "Acknowledgements", "Dedications", or "History", the requirement (section 4) to Preserve its Title (section 1) will typically require changing the actual title. 9. TERMINATION You may not copy, modify, sublicense, or distribute the Document except as expressly provided under this License. Any attempt otherwise to copy, modify, sublicense, or distribute it is void, and will automatically terminate your rights under this License. However, if you cease all violation of this License, then your license from a particular copyright holder is reinstated (a) provisionally, unless and until the copyright holder explicitly and finally terminates your license, and (b) permanently, if the copyright holder fails to notify you of the violation by some reasonable means prior to 60 days after the cessation. Moreover, your license from a particular copyright holder is reinstated permanently if the copyright holder notifies you of the violation by some reasonable means, this is the first time you have received notice of violation of this License (for any work) from that copyright holder, and you cure the violation prior to 30 days after your receipt of the notice. Termination of your rights under this section does not terminate the licenses of parties who have received copies or rights from you under this License. If your rights have been terminated and not permanently reinstated, receipt of a copy of some or all of the same material does not give you any rights to use it. 10. FUTURE REVISIONS OF THIS LICENSE The Free Software Foundation may publish new, revised versions of the GNU Free Documentation License from time to time. Such new versions will be similar in spirit to the present version, but may differ in detail to address new problems or concerns. See `http://www.gnu.org/copyleft/'. Each version of the License is given a distinguishing version number. If the Document specifies that a particular numbered version of this License "or any later version" applies to it, you have the option of following the terms and conditions either of that specified version or of any later version that has been published (not as a draft) by the Free Software Foundation. If the Document does not specify a version number of this License, you may choose any version ever published (not as a draft) by the Free Software Foundation. If the Document specifies that a proxy can decide which future versions of this License can be used, that proxy's public statement of acceptance of a version permanently authorizes you to choose that version for the Document. 11. RELICENSING "Massive Multiauthor Collaboration Site" (or "MMC Site") means any World Wide Web server that publishes copyrightable works and also provides prominent facilities for anybody to edit those works. A public wiki that anybody can edit is an example of such a server. A "Massive Multiauthor Collaboration" (or "MMC") contained in the site means any set of copyrightable works thus published on the MMC site. "CC-BY-SA" means the Creative Commons Attribution-Share Alike 3.0 license published by Creative Commons Corporation, a not-for-profit corporation with a principal place of business in San Francisco, California, as well as future copyleft versions of that license published by that same organization. "Incorporate" means to publish or republish a Document, in whole or in part, as part of another Document. An MMC is "eligible for relicensing" if it is licensed under this License, and if all works that were first published under this License somewhere other than this MMC, and subsequently incorporated in whole or in part into the MMC, (1) had no cover texts or invariant sections, and (2) were thus incorporated prior to November 1, 2008. The operator of an MMC Site may republish an MMC contained in the site under CC-BY-SA on the same site at any time before August 1, 2009, provided the MMC is eligible for relicensing. ADDENDUM: How to use this License for your documents ==================================================== To use this License in a document you have written, include a copy of the License in the document and put the following copyright and license notices just after the title page: Copyright (C) YEAR YOUR NAME. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.3 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled ``GNU Free Documentation License''. If you have Invariant Sections, Front-Cover Texts and Back-Cover Texts, replace the "with...Texts." line with this: with the Invariant Sections being LIST THEIR TITLES, with the Front-Cover Texts being LIST, and with the Back-Cover Texts being LIST. If you have Invariant Sections without Cover Texts, or some other combination of the three, merge those two alternatives to suit the situation. If your document contains nontrivial examples of program code, we recommend releasing these examples in parallel under your choice of free software license, such as the GNU General Public License, to permit their use in free software. Appendix B Request Index ************************ Requests appear without the leading control character (normally either `.' or `''). ab: See 5.33. (line 10517) ad: See 5.7. (line 4684) af: See 5.6.4. (line 4438) aln: See 5.6.1. (line 4338) als: See 5.19. (line 7915) am: See 5.21. (line 8341) am1: See 5.21. (line 8342) ami: See 5.21. (line 8343) ami1: See 5.21. (line 8344) as: See 5.19. (line 7861) as1: See 5.19. (line 7862) asciify: See 5.25. (line 9608) backtrace: See 5.33. (line 10575) bd: See 5.17.7. (line 7241) blm: See 5.24.4. (line 9273) box: See 5.25. (line 9438) boxa: See 5.25. (line 9439) bp: See 5.16. (line 6232) br: See 5.7. (line 4644) break: See 5.20.3. (line 8216) brp: See 5.7. (line 4766) c2: See 5.11. (line 5589) cc: See 5.11. (line 5583) ce: See 5.7. (line 4843) cf: See 5.29. (line 9959) cflags: See 5.17.4. (line 6876) ch: See 5.24.1. (line 9160) char: See 5.17.4. (line 6963) chop: See 5.19. (line 7954) class: See 5.17.5. (line 7059) close: See 5.29. (line 10149) color: See 5.28. (line 9810) composite: See 5.17.4. (line 6829) continue: See 5.20.3. (line 8220) cp: See 5.34. (line 10791) cs: See 5.17.7. (line 7272) cu: See 5.17.7. (line 7232) da: See 5.25. (line 9426) de: See 5.21. (line 8237) de1: See 5.21. (line 8238) defcolor: See 5.28. (line 9824) dei: See 5.21. (line 8239) dei1: See 5.21. (line 8240) device: See 5.30. (line 10181) devicem: See 5.30. (line 10199) di: See 5.25. (line 9425) do: See 5.34. (line 10792) ds: See 5.19. (line 7689) ds1: See 5.19. (line 7690) dt: See 5.24.2. (line 9229) ec: See 5.11. (line 5622) ecr: See 5.11. (line 5634) ecs: See 5.11. (line 5633) el: See 5.20.2. (line 8117) em: See 5.24.6. (line 9309) eo: See 5.11. (line 5597) ev: See 5.26. (line 9675) evc: See 5.26. (line 9709) ex: See 5.33. (line 10522) fam: See 5.17.2. (line 6458) fc: See 5.10.2. (line 5553) fchar: See 5.17.4. (line 6964) fcolor: See 5.28. (line 9888) fi: See 5.7. (line 4662) fl: See 5.33. (line 10566) fp: See 5.17.3. (line 6567) fschar: See 5.17.4. (line 6965) fspecial: See 5.17.6. (line 7131) ft <1>: See 5.17.3. (line 6614) ft: See 5.17.1. (line 6349) ftr: See 5.17.1. (line 6399) fzoom: See 5.17.1. (line 6415) gcolor: See 5.28. (line 9854) hc: See 5.8. (line 5002) hcode: See 5.8. (line 5073) hla: See 5.8. (line 5151) hlm: See 5.8. (line 4942) hpf: See 5.8. (line 5011) hpfa: See 5.8. (line 5012) hpfcode: See 5.8. (line 5013) hw: See 5.8. (line 4958) hy: See 5.8. (line 4906) hym: See 5.8. (line 5107) hys: See 5.8. (line 5122) ie: See 5.20.2. (line 8116) if: See 5.20.2. (line 8099) ig: See 5.5.3.1. (line 4184) in: See 5.13. (line 5963) it: See 5.24.3. (line 9243) itc: See 5.24.3. (line 9244) kern: See 5.17.8. (line 7319) lc: See 5.10.1. (line 5512) length: See 5.19. (line 7895) lf: See 5.33. (line 10487) lg: See 5.17.8. (line 7301) linetabs: See 5.10. (line 5458) ll: See 5.13. (line 6017) ls: See 5.9. (line 5237) lsm: See 5.24.5. (line 9280) lt: See 5.15. (line 6193) mc: See 5.31. (line 10286) mk: See 5.22. (line 8538) mso: See 5.29. (line 9949) na: See 5.7. (line 4758) ne: See 5.16. (line 6259) nf: See 5.7. (line 4673) nh: See 5.8. (line 4934) nm: See 5.31. (line 10220) nn: See 5.31. (line 10282) nop: See 5.20.2. (line 8113) nr <1>: See 5.6.3. (line 4381) nr: See 5.6.1. (line 4233) nroff: See 5.12. (line 5866) ns: See 5.9. (line 5299) nx: See 5.29. (line 9993) open: See 5.29. (line 10117) opena: See 5.29. (line 10118) os: See 5.16. (line 6280) output: See 5.25. (line 9593) pc: See 5.15. (line 6222) pev: See 5.33. (line 10541) pi: See 5.29. (line 10057) pl: See 5.15. (line 6139) pm: See 5.33. (line 10545) pn: See 5.15. (line 6210) pnr: See 5.33. (line 10556) po: See 5.13. (line 5933) ps: See 5.18.1. (line 7459) psbb: See 5.31. (line 10351) pso: See 5.29. (line 9938) ptr: See 5.33. (line 10560) pvs: See 5.18.1. (line 7585) rchar: See 5.17.4. (line 7022) rd: See 5.29. (line 9998) return: See 5.21. (line 8378) rfschar: See 5.17.4. (line 7023) rj: See 5.7. (line 4892) rm: See 5.19. (line 7910) rn: See 5.19. (line 7907) rnn: See 5.6.1. (line 4334) rr: See 5.6.1. (line 4330) rs: See 5.9. (line 5300) rt: See 5.22. (line 8539) schar: See 5.17.4. (line 6966) shc: See 5.8. (line 5138) shift: See 5.21.2. (line 8450) sizes: See 5.18.1. (line 7521) so: See 5.29. (line 9917) sp: See 5.9. (line 5175) special: See 5.17.6. (line 7130) spreadwarn: See 5.33. (line 10613) ss: See 5.7. (line 4788) sty: See 5.17.2. (line 6499) substring: See 5.19. (line 7879) sv: See 5.16. (line 6279) sy: See 5.29. (line 10079) ta: See 5.10. (line 5325) tc: See 5.10. (line 5450) ti: See 5.13. (line 5989) tkf: See 5.17.8. (line 7338) tl: See 5.15. (line 6164) tm: See 5.33. (line 10502) tm1: See 5.33. (line 10503) tmc: See 5.33. (line 10504) tr: See 5.11. (line 5728) trf: See 5.29. (line 9958) trin: See 5.11. (line 5729) trnt: See 5.11. (line 5820) troff: See 5.12. (line 5858) uf: See 5.17.7. (line 7236) ul: See 5.17.7. (line 7210) unformat: See 5.25. (line 9632) vpt: See 5.24.1. (line 9058) vs: See 5.18.1. (line 7536) warn: See 5.33. (line 10636) warnscale: See 5.33. (line 10608) wh: See 5.24.1. (line 9070) while: See 5.20.3. (line 8153) write: See 5.29. (line 10129) writec: See 5.29. (line 10130) writem: See 5.29. (line 10140) Appendix C Escape Index *********************** Any escape sequence `\X' with X not in the list below emits a warning, printing glyph X. \: See 5.17.4. (line 6771) \!: See 5.25. (line 9546) \": See 5.5.3.1. (line 4127) \#: See 5.5.3.1. (line 4167) \$: See 5.21.2. (line 8439) \$*: See 5.21.2. (line 8458) \$0: See 5.21.2. (line 8490) \$@: See 5.21.2. (line 8459) \$^: See 5.21.2. (line 8468) \%: See 5.8. (line 4981) \&: See 5.17.8. (line 7380) \': See 5.17.4. (line 6861) \): See 5.17.8. (line 7409) \*: See 5.19. (line 7691) \,: See 5.17.8. (line 7370) \-: See 5.17.4. (line 6870) \.: See 5.11. (line 5701) \/: See 5.17.8. (line 7358) \0: See 5.22. (line 8675) \: See 5.8. (line 4982) \: See 5.14. (line 6083) \: See 5.22. (line 8651) \?: See 5.25. (line 9547) \\: See 5.11. (line 5643) \^: See 5.22. (line 8667) \_: See 5.17.4. (line 6873) \`: See 5.17.4. (line 6866) \a: See 5.10.1. (line 5507) \A: See 5.4. (line 3794) \b: See 5.23. (line 9014) \B: See 5.3. (line 3730) \C: See 5.17.4. (line 6823) \c: See 5.14. (line 6084) \D: See 5.23. (line 8846) \d: See 5.22. (line 8637) \E: See 5.11. (line 5645) \e: See 5.11. (line 5644) \f: See 5.17.3. (line 6615) \F: See 5.17.2. (line 6460) \f: See 5.17.1. (line 6350) \g: See 5.6.4. (line 4500) \h: See 5.22. (line 8640) \H: See 5.17.7. (line 7156) \k: See 5.22. (line 8739) \L: See 5.23. (line 8825) \l: See 5.23. (line 8791) \M: See 5.28. (line 9889) \m: See 5.28. (line 9855) \N: See 5.17.4. (line 6839) \n <1>: See 5.6.3. (line 4389) \n: See 5.6.2. (line 4349) \O: See 5.27. (line 9756) \o: See 5.22. (line 8754) \p: See 5.7. (line 4767) \r: See 5.22. (line 8631) \R: See 5.6.1. (line 4234) \s: See 5.18.1. (line 7462) \S: See 5.17.7. (line 7189) \t: See 5.10. (line 5321) \u: See 5.22. (line 8634) \V: See 5.29. (line 10167) \v: See 5.22. (line 8615) \w: See 5.22. (line 8683) \X: See 5.30. (line 10182) \x: See 5.9. (line 5257) \Y: See 5.30. (line 10200) \Z: See 5.22. (line 8762) \z: See 5.22. (line 8758) \{: See 5.20.2. (line 8127) \|: See 5.22. (line 8659) \}: See 5.20.2. (line 8127) \~: See 5.22. (line 8655) Appendix D Operator Index ************************* !: See 5.3. (line 3667) %: See 5.3. (line 3654) &: See 5.3. (line 3665) (: See 5.3. (line 3706) ): See 5.3. (line 3706) *: See 5.3. (line 3654) +: See 5.3. (line 3654) -: See 5.3. (line 3654) /: See 5.3. (line 3654) <: See 5.3. (line 3661) <=: See 5.3. (line 3661) : See 5.3. (line 3665) =: See 5.3. (line 3661) ==: See 5.3. (line 3661) >: See 5.3. (line 3661) >=: See 5.3. (line 3661) >?: See 5.3. (line 3691) Appendix E Register Index ************************* The macro package or program a specific register belongs to is appended in brackets. A register name `x' consisting of exactly one character can be accessed as `\nx'. A register name `xx' consisting of exactly two characters can be accessed as `\n(xx'. Register names `xxx' of any length can be accessed as `\n[xxx]'. $$: See 5.6.5. (line 4604) % <1>: See 5.16. (line 6235) %: See 5.15. (line 6222) .$: See 5.21.2. (line 8430) .a: See 5.9. (line 5258) .A: See 5.6.5. (line 4611) .b: See 5.17.7. (line 7243) .br: See 5.5.1. (line 3924) .C: See 5.34. (line 10793) .c: See 5.6.5. (line 4581) .cdp: See 5.26. (line 9733) .ce: See 5.7. (line 4844) .cht: See 5.26. (line 9732) .color: See 5.28. (line 9811) .csk: See 5.26. (line 9734) .d: See 5.25. (line 9475) .ev: See 5.26. (line 9676) .f: See 5.17.3. (line 6568) .F: See 5.6.5. (line 4516) .fam: See 5.17.2. (line 6459) .fn: See 5.17.2. (line 6463) .fp: See 5.17.3. (line 6569) .g: See 5.6.5. (line 4607) .h: See 5.25. (line 9482) .H: See 5.6.5. (line 4519) .height: See 5.17.7. (line 7159) .hla: See 5.8. (line 5152) .hlc: See 5.8. (line 4944) .hlm: See 5.8. (line 4943) .hy: See 5.8. (line 4907) .hym: See 5.8. (line 5108) .hys: See 5.8. (line 5123) .i: See 5.13. (line 5966) .in: See 5.13. (line 5992) .int: See 5.14. (line 6085) .j: See 5.7. (line 4685) .k: See 5.22. (line 8750) .kern: See 5.17.8. (line 7320) .l: See 5.13. (line 6020) .L: See 5.9. (line 5238) .lg: See 5.17.8. (line 7302) .linetabs: See 5.10. (line 5459) .ll: See 5.13. (line 6021) .lt: See 5.15. (line 6196) .M: See 5.28. (line 9892) .m: See 5.28. (line 9858) .n: See 5.26. (line 9749) .ne: See 5.24.1. (line 9172) .ns: See 5.9. (line 5301) .o: See 5.13. (line 5936) .O: See 5.6.5. (line 4616) .p: See 5.15. (line 6142) .P: See 5.6.5. (line 4620) .pe: See 5.24.1. (line 9193) .pn: See 5.15. (line 6213) .ps: See 5.18.2. (line 7633) .psr: See 5.18.2. (line 7640) .pvs: See 5.18.1. (line 7588) .R: See 5.6.5. (line 4522) .rj: See 5.7. (line 4893) .s: See 5.18.1. (line 7463) .slant: See 5.17.7. (line 7190) .sr: See 5.18.2. (line 7641) .ss: See 5.7. (line 4789) .sss: See 5.7. (line 4790) .sty: See 5.17.1. (line 6353) .t: See 5.24.1. (line 9151) .T: See 5.6.5. (line 4626) .tabs: See 5.10. (line 5326) .trunc: See 5.24.1. (line 9181) .u: See 5.7. (line 4663) .U: See 5.6.5. (line 4526) .v: See 5.18.1. (line 7539) .V: See 5.6.5. (line 4531) .vpt: See 5.24.1. (line 9059) .w: See 5.26. (line 9731) .warn: See 5.33. (line 10637) .x: See 5.6.5. (line 4593) .Y: See 5.6.5. (line 4601) .y: See 5.6.5. (line 4597) .z: See 5.25. (line 9474) .zoom: See 5.17.1. (line 6416) c.: See 5.6.5. (line 4582) ct: See 5.22. (line 8688) DD [ms]: See 4.3.3. (line 2236) dl: See 5.25. (line 9500) dn: See 5.25. (line 9499) dw: See 5.6.5. (line 4547) dy: See 5.6.5. (line 4550) FAM [ms]: See 4.3.3. (line 2107) FF [ms]: See 4.3.3. (line 2181) FI [ms]: See 4.3.3. (line 2174) FL [ms]: See 4.3.3. (line 2167) FM [ms]: See 4.3.3. (line 2044) FPD [ms]: See 4.3.3. (line 2218) FPS [ms]: See 4.3.3. (line 2201) FVS [ms]: See 4.3.3. (line 2209) GROWPS [ms]: See 4.3.3. (line 2085) GS [ms]: See 4.3.7. (line 3230) HM [ms]: See 4.3.3. (line 2037) HORPHANS [ms]: See 4.3.3. (line 2151) hours: See 5.6.5. (line 4543) hp: See 5.22. (line 8747) HY [ms]: See 4.3.3. (line 2098) LL [ms]: See 4.3.3. (line 2022) llx: See 5.31. (line 10352) lly: See 5.31. (line 10353) ln: See 5.6.5. (line 4587) lsn: See 5.24.5. (line 9281) lss: See 5.24.5. (line 9282) LT [ms]: See 4.3.3. (line 2029) MINGW [ms] <1>: See 4.3.7.2. (line 3310) MINGW [ms]: See 4.3.3. (line 2228) minutes: See 5.6.5. (line 4539) mo: See 5.6.5. (line 4553) nl: See 5.16. (line 6293) opmaxx: See 5.27. (line 9768) opmaxy: See 5.27. (line 9768) opminx: See 5.27. (line 9768) opminy: See 5.27. (line 9768) PD [ms]: See 4.3.3. (line 2124) PI [ms]: See 4.3.3. (line 2117) PO [ms]: See 4.3.3. (line 2013) PORPHANS [ms]: See 4.3.3. (line 2139) PS [ms]: See 4.3.3. (line 2054) ps4html [grohtml]: See 7.8.2. (line 11393) PSINCR [ms]: See 4.3.3. (line 2074) QI [ms]: See 4.3.3. (line 2131) rsb: See 5.22. (line 8687) rst: See 5.22. (line 8686) sb: See 5.22. (line 8685) seconds: See 5.6.5. (line 4534) skw: See 5.22. (line 8690) slimit: See 5.33. (line 10600) ssc: See 5.22. (line 8689) st: See 5.22. (line 8684) systat: See 5.29. (line 10080) urx: See 5.31. (line 10354) ury: See 5.31. (line 10355) VS [ms]: See 4.3.3. (line 2064) year: See 5.6.5. (line 4556) yr: See 5.6.5. (line 4559) Appendix F Macro Index ********************** The macro package a specific macro belongs to is appended in brackets. They appear without the leading control character (normally `.'). 1C [ms]: See 4.3.6.3. (line 2969) 2C [ms]: See 4.3.6.3. (line 2972) [ [ms]: See 4.3.5.8. (line 2847) ] [ms]: See 4.3.5.8. (line 2848) AB [ms]: See 4.3.4. (line 2300) AE [ms]: See 4.3.4. (line 2305) AI [ms]: See 4.3.4. (line 2296) AM [ms] <1>: See 4.3.7.2. (line 3292) AM [ms]: See 4.3.6.5. (line 3105) AT [man]: See 4.1.4. (line 1724) AU [ms]: See 4.3.4. (line 2278) B [man]: See 4.1.3. (line 1693) B [ms]: See 4.3.5.3. (line 2474) B1 [ms]: See 4.3.5.7. (line 2812) B2 [ms]: See 4.3.5.7. (line 2813) BD [ms]: See 4.3.5.7. (line 2749) BI [man]: See 4.1.3. (line 1663) BI [ms]: See 4.3.5.3. (line 2503) BR [man]: See 4.1.3. (line 1685) BT [man]: See 4.1.7. (line 1813) BT [ms]: See 4.3.6.1. (line 2946) BX [ms]: See 4.3.5.3. (line 2507) CD [ms]: See 4.3.5.7. (line 2759) CT [man]: See 4.1.7. (line 1828) CW [man]: See 4.1.7. (line 1831) CW [ms] <1>: See 4.3.7.2. (line 3301) CW [ms]: See 4.3.5.3. (line 2499) DA [ms]: See 4.3.4. (line 2263) De [man]: See 4.1.7. (line 1837) De [ms]: See 4.3.5.7. (line 2775) DE [ms]: See 4.3.5.7. (line 2734) Ds [man]: See 4.1.7. (line 1834) DS [ms]: See 4.3.7.2. (line 3296) Ds [ms]: See 4.3.5.7. (line 2774) DS [ms]: See 4.3.5.7. (line 2732) DT [man]: See 4.1.4. (line 1708) EE [man]: See 4.1.7. (line 1844) EF [ms]: See 4.3.6.1. (line 2932) EH [ms]: See 4.3.6.1. (line 2930) EN [ms]: See 4.3.5.8. (line 2842) EQ [ms]: See 4.3.5.8. (line 2841) EX [man]: See 4.1.7. (line 1840) FE [ms]: See 4.3.5.10. (line 2883) FS [ms]: See 4.3.5.10. (line 2882) G [man]: See 4.1.7. (line 1847) GL [man]: See 4.1.7. (line 1852) HB [man]: See 4.1.7. (line 1857) HD [ms]: See 4.3.6.1. (line 2945) HP [man]: See 4.1.2. (line 1616) I [man]: See 4.1.3. (line 1698) I [ms]: See 4.3.5.3. (line 2495) IB [man]: See 4.1.3. (line 1673) ID [ms]: See 4.3.5.7. (line 2741) IP [man]: See 4.1.2. (line 1596) IP [ms]: See 4.3.5.4. (line 2541) IR [man]: See 4.1.3. (line 1681) IX [ms]: See 4.3.7.2. (line 3304) KE [ms]: See 4.3.5.7. (line 2791) KF [ms]: See 4.3.5.7. (line 2795) KS [ms]: See 4.3.5.7. (line 2790) LD [ms]: See 4.3.5.7. (line 2733) LG [ms]: See 4.3.5.3. (line 2516) LP [man]: See 4.1.2. (line 1586) LP [ms]: See 4.3.5.1. (line 2353) MC [ms]: See 4.3.6.3. (line 2975) MS [man]: See 4.1.7. (line 1865) ND [ms]: See 4.3.4. (line 2268) NE [man]: See 4.1.7. (line 1877) NH [ms]: See 4.3.5.2. (line 2411) NL [ms]: See 4.3.5.3. (line 2528) NT [man]: See 4.1.7. (line 1870) OF [ms]: See 4.3.6.1. (line 2931) OH [ms]: See 4.3.6.1. (line 2929) P [man]: See 4.1.2. (line 1588) P1 [ms]: See 4.3.4. (line 2259) PD [man]: See 4.1.4. (line 1713) PE [ms]: See 4.3.5.8. (line 2835) Pn [man]: See 4.1.7. (line 1884) PN [man]: See 4.1.7. (line 1880) PP [man]: See 4.1.2. (line 1587) PP [ms]: See 4.3.5.1. (line 2350) PS [ms]: See 4.3.5.8. (line 2834) PT [man]: See 4.1.7. (line 1808) PT [ms]: See 4.3.6.1. (line 2944) PX [ms]: See 4.3.6.4. (line 3042) QP [ms]: See 4.3.5.1. (line 2356) R [man]: See 4.1.7. (line 1890) R [ms]: See 4.3.5.3. (line 2491) RB [man]: See 4.1.3. (line 1689) RD [ms]: See 4.3.5.7. (line 2767) RE [man]: See 4.1.2. (line 1633) RE [ms]: See 4.3.5.5. (line 2703) RI [man]: See 4.1.3. (line 1677) RN [man]: See 4.1.7. (line 1893) RP [ms]: See 4.3.4. (line 2250) RS [man]: See 4.1.2. (line 1624) RS [ms]: See 4.3.5.5. (line 2702) SB [man]: See 4.1.3. (line 1659) SH [man]: See 4.1.2. (line 1550) SH [ms]: See 4.3.5.2. (line 2453) SM [man]: See 4.1.3. (line 1655) SM [ms]: See 4.3.5.3. (line 2522) SS [man]: See 4.1.2. (line 1559) TA [ms]: See 4.3.5.6. (line 2717) TB [man]: See 4.1.7. (line 1862) TC [ms]: See 4.3.6.4. (line 3032) TE [ms]: See 4.3.5.8. (line 2826) TH [man]: See 4.1.2. (line 1528) TL [ms]: See 4.3.4. (line 2273) TP [man]: See 4.1.2. (line 1567) TS [ms]: See 4.3.5.8. (line 2825) UC [man]: See 4.1.4. (line 1741) UL [ms]: See 4.3.5.3. (line 2511) VE [man]: See 4.1.7. (line 1900) VS [man]: See 4.1.7. (line 1896) XA [ms]: See 4.3.6.4. (line 2990) XE [ms]: See 4.3.6.4. (line 2991) XP [ms]: See 4.3.5.1. (line 2361) XS [ms]: See 4.3.6.4. (line 2989) Appendix G String Index *********************** The macro package or program a specific string belongs to is appended in brackets. A string name `x' consisting of exactly one character can be accessed as `\*x'. A string name `xx' consisting of exactly two characters can be accessed as `\*(xx'. String names `xxx' of any length can be accessed as `\*[xxx]'. ! [ms]: See 4.3.6.5. (line 3155) ' [ms]: See 4.3.6.5. (line 3119) * [ms]: See 4.3.5.10. (line 2879) , [ms]: See 4.3.6.5. (line 3128) - [ms]: See 4.3.6.5. (line 3095) . [ms]: See 4.3.6.5. (line 3143) .T: See 5.6.5. (line 4631) 3 [ms]: See 4.3.6.5. (line 3161) 8 [ms]: See 4.3.6.5. (line 3158) ? [ms]: See 4.3.6.5. (line 3152) \*[] [ms]: See 4.3.6.5. (line 3134) ^ [ms]: See 4.3.6.5. (line 3125) _ [ms]: See 4.3.6.5. (line 3140) ` [ms]: See 4.3.6.5. (line 3122) ABSTRACT [ms]: See 4.3.6.5. (line 3069) Ae [ms]: See 4.3.6.5. (line 3182) ae [ms]: See 4.3.6.5. (line 3179) CF [ms]: See 4.3.6.1. (line 2922) CH [ms]: See 4.3.6.1. (line 2917) d- [ms]: See 4.3.6.5. (line 3173) D- [ms]: See 4.3.6.5. (line 3170) HF [man]: See 4.1.5. (line 1768) LF [ms]: See 4.3.6.1. (line 2921) LH [ms]: See 4.3.6.1. (line 2916) lq [man]: See 4.1.5. (line 1777) MONTH1 [ms]: See 4.3.6.5. (line 3077) MONTH10 [ms]: See 4.3.6.5. (line 3086) MONTH11 [ms]: See 4.3.6.5. (line 3087) MONTH12 [ms]: See 4.3.6.5. (line 3088) MONTH2 [ms]: See 4.3.6.5. (line 3078) MONTH3 [ms]: See 4.3.6.5. (line 3079) MONTH4 [ms]: See 4.3.6.5. (line 3080) MONTH5 [ms]: See 4.3.6.5. (line 3081) MONTH6 [ms]: See 4.3.6.5. (line 3082) MONTH7 [ms]: See 4.3.6.5. (line 3083) MONTH8 [ms]: See 4.3.6.5. (line 3084) MONTH9 [ms]: See 4.3.6.5. (line 3085) o [ms]: See 4.3.6.5. (line 3146) q [ms]: See 4.3.6.5. (line 3176) Q [ms]: See 4.3.6.5. (line 3098) R [man]: See 4.1.5. (line 1771) REFERENCES [ms]: See 4.3.6.5. (line 3065) RF [ms]: See 4.3.6.1. (line 2923) RH [ms]: See 4.3.6.1. (line 2918) rq [man]: See 4.1.5. (line 1778) S [man]: See 4.1.5. (line 1765) SN [ms]: See 4.3.5.2. (line 2420) SN-DOT [ms]: See 4.3.5.2. (line 2421) SN-NO-DOT [ms]: See 4.3.5.2. (line 2422) SN-STYLE [ms]: See 4.3.5.2. (line 2435) th [ms]: See 4.3.6.5. (line 3167) Th [ms]: See 4.3.6.5. (line 3164) Tm [man]: See 4.1.5. (line 1774) TOC [ms]: See 4.3.6.5. (line 3073) U [ms]: See 4.3.6.5. (line 3099) v [ms]: See 4.3.6.5. (line 3137) www-image-template [grohtml]: See 7.8.2. (line 11394) { [ms]: See 4.3.5.3. (line 2532) } [ms]: See 4.3.5.3. (line 2533) ~ [ms]: See 4.3.6.5. (line 3131) Appendix H Glyph Name Index *************************** A glyph name `xx' consisting of exactly two characters can be accessed as `\(xx'. Glyph names `xxx' of any length can be accessed as `\[xxx]'. Appendix I Font File Keyword Index ********************************** #: See 8.2.2. (line 12349) ---: See 8.2.2. (line 12364) biggestfont: See 8.2.1. (line 12313) charset <1>: See 8.2.2. (line 12357) charset: See 8.2.1. (line 12181) family <1>: See 8.2.1. (line 12185) family <2>: See 5.17.3. (line 6617) family: See 5.17.1. (line 6353) fonts <1>: See 8.2.1. (line 12188) fonts <2>: See 5.17.6. (line 7131) fonts: See 5.17.4. (line 6648) hor: See 8.2.1. (line 12194) image_generator: See 8.2.1. (line 12198) kernpairs: See 8.2.2. (line 12448) ligatures: See 8.2.2. (line 12335) name: See 8.2.2. (line 12325) paperlength: See 8.2.1. (line 12204) papersize: See 8.2.1. (line 12209) paperwidth: See 8.2.1. (line 12229) pass_filenames: See 8.2.1. (line 12234) postpro: See 8.2.1. (line 12239) prepro: See 8.2.1. (line 12248) print: See 8.2.1. (line 12252) res: See 8.2.1. (line 12256) sizes: See 8.2.1. (line 12259) sizescale: See 8.2.1. (line 12265) slant: See 8.2.2. (line 12331) spacewidth: See 8.2.2. (line 12328) spare1: See 8.2.1. (line 12313) spare2: See 8.2.1. (line 12313) special <1>: See 8.2.2. (line 12341) special: See 5.17.7. (line 7261) styles <1>: See 8.2.1. (line 12271) styles <2>: See 5.17.3. (line 6617) styles <3>: See 5.17.2. (line 6514) styles: See 5.17.1. (line 6353) tcommand: See 8.2.1. (line 12274) unicode: See 8.2.1. (line 12278) unitwidth: See 8.2.1. (line 12292) unscaled_charwidths: See 8.2.1. (line 12296) use_charnames_in_special <1>: See 8.2.1. (line 12300) use_charnames_in_special: See 5.30. (line 10191) vert: See 8.2.1. (line 12305) Appendix J Program and File Index ********************************* an.tmac: See 4.1. (line 1432) changebar: See 5.31. (line 10321) composite.tmac: See 5.17.4. (line 6829) cp1047.tmac: See 5.1.7. (line 3515) DESC <1>: See 5.17.6. (line 7131) DESC <2>: See 5.17.4. (line 6648) DESC <3>: See 5.17.3. (line 6617) DESC <4>: See 5.17.2. (line 6514) DESC: See 5.17.1. (line 6353) DESC file format: See 8.2.1. (line 12175) DESC, and font mounting: See 5.17.3. (line 6593) DESC, and use_charnames_in_special: See 5.30. (line 10191) ditroff: See 1.2. (line 349) ec.tmac: See 5.1.7. (line 3552) eqn: See 4.3.5.8. (line 2821) freeeuro.pfa: See 5.1.7. (line 3552) gchem: See 2.1. (line 537) geqn: See 2.1. (line 537) geqn, invocation in manual pages: See 4.1.6. (line 1790) ggrn: See 2.1. (line 537) gpic: See 2.1. (line 537) grap: See 2.1. (line 537) grefer: See 2.1. (line 537) grefer, invocation in manual pages: See 4.1.6. (line 1790) groff: See 2.1. (line 537) grog: See 2.6.1. (line 1059) grohtml: See 4.1.4. (line 1704) gsoelim: See 2.1. (line 537) gtbl: See 2.1. (line 537) gtbl, invocation in manual pages: See 4.1.6. (line 1790) gtroff: See 2.1. (line 537) hyphen.us: See 5.8. (line 5060) hyphenex.us: See 5.8. (line 5060) latin1.tmac: See 5.1.7. (line 3520) latin2.tmac: See 5.1.7. (line 3524) latin9.tmac: See 5.1.7. (line 3534) less: See 7.2.1. (line 11023) makeindex: See 3.2.8. (line 1364) man, invocation of preprocessors: See 4.1.6. (line 1790) man-old.tmac: See 4.1. (line 1432) man.local <1>: See 4.1.7. (line 1798) man.local: See 4.1.2. (line 1523) man.tmac: See 4.1. (line 1432) man.ultrix: See 4.1.7. (line 1822) nrchbar: See 5.31. (line 10321) papersize.tmac: See 2.5. (line 998) perl: See 5.29. (line 10090) pic: See 4.3.5.8. (line 2821) post-grohtml: See 2.1. (line 806) pre-grohtml: See 2.1. (line 806) preconv: See 2.1. (line 537) refer: See 4.3.5.8. (line 2821) soelim: See 5.33. (line 10487) tbl: See 4.3.5.8. (line 2821) trace.tmac: See 5.21. (line 8332) troffrc <1>: See 5.13. (line 5936) troffrc <2>: See 5.12. (line 5858) troffrc <3>: See 5.8. (line 5060) troffrc <4>: See 2.5. (line 998) troffrc: See 2.1. (line 739) troffrc-end <1>: See 5.12. (line 5858) troffrc-end <2>: See 5.8. (line 5060) troffrc-end: See 2.1. (line 739) tty.tmac: See 5.12. (line 5866) Appendix K Concept Index ************************ ", at end of sentence <1>: See 5.17.4. (line 6914) ", at end of sentence: See 5.1.3. (line 3434) ", in a macro argument: See 5.5.1.1. (line 3968) %, as delimiter: See 5.5.3. (line 4104) &, as delimiter: See 5.5.3. (line 4104) ', as a comment: See 5.5.3.1. (line 4161) ', at end of sentence <1>: See 5.17.4. (line 6914) ', at end of sentence: See 5.1.3. (line 3434) ', delimiting arguments: See 5.5.3. (line 4064) (, as delimiter: See 5.5.3. (line 4104) (, starting a two-character identifier <1>: See 5.5.3. (line 4050) (, starting a two-character identifier: See 5.4. (line 3814) ), as delimiter: See 5.5.3. (line 4104) ), at end of sentence <1>: See 5.17.4. (line 6914) ), at end of sentence: See 5.1.3. (line 3434) *, as delimiter: See 5.5.3. (line 4104) *, at end of sentence <1>: See 5.17.4. (line 6914) *, at end of sentence: See 5.1.3. (line 3434) +, and page motion: See 5.3. (line 3712) +, as delimiter: See 5.5.3. (line 4104) -, and page motion: See 5.3. (line 3712) -, as delimiter: See 5.5.3. (line 4104) ., as delimiter: See 5.5.3. (line 4104) .h register, difference to nl: See 5.25. (line 9495) .ps register, in comparison with .psr: See 5.18.2. (line 7641) .s register, in comparison with .sr: See 5.18.2. (line 7641) .S register, Plan 9 alias for .tabs: See 5.10. (line 5446) .t register, and diversions: See 5.24.2. (line 9229) .tabs register, Plan 9 alias (.S): See 5.10. (line 5446) .V register, and vs: See 5.18.1. (line 7545) /, as delimiter: See 5.5.3. (line 4104) 8-bit input: See 8.2.2. (line 12364) <, as delimiter: See 5.5.3. (line 4104) , as delimiter: See 5.5.3. (line 4104) =, as delimiter: See 5.5.3. (line 4104) >, as delimiter: See 5.5.3. (line 4104) [, macro names starting with, and refer: See 5.4. (line 3787) [, starting an identifier <1>: See 5.5.3. (line 4054) [, starting an identifier: See 5.4. (line 3816) \!, and copy-in mode: See 5.25. (line 9560) \!, and output request: See 5.25. (line 9592) \!, and trnt: See 5.11. (line 5820) \!, in top-level diversion: See 5.25. (line 9584) \!, incompatibilities with AT&T troff: See 5.34. (line 10840) \!, used as delimiter: See 5.5.3. (line 4089) \$, when reading text for a macro: See 5.21.1. (line 8400) \%, and translations: See 5.11. (line 5745) \%, following \X or \Y: See 5.8. (line 4996) \%, in \X: See 5.30. (line 10184) \%, incompatibilities with AT&T troff: See 5.34. (line 10840) \%, used as delimiter: See 5.5.3. (line 4089) \&, and glyph definitions: See 5.17.4. (line 6966) \&, and translations: See 5.11. (line 5755) \&, at end of sentence: See 5.1.3. (line 3440) \&, escaping control characters: See 5.5.1. (line 3915) \&, in \X: See 5.30. (line 10184) \&, incompatibilities with AT&T troff: See 5.34. (line 10840) \&, used as delimiter: See 5.5.3. (line 4089) \', and translations: See 5.11. (line 5739) \', incompatibilities with AT&T troff: See 5.34. (line 10840) \', used as delimiter: See 5.5.3. (line 4089) \(, and translations: See 5.11. (line 5739) \), in \X: See 5.30. (line 10184) \), used as delimiter: See 5.5.3. (line 4089) \*, and warnings: See 5.33.1. (line 10698) \*, incompatibilities with AT&T troff: See 5.34. (line 10782) \*, when reading text for a macro: See 5.21.1. (line 8400) \, disabling (eo): See 5.11. (line 5597) \,, used as delimiter: See 5.5.3. (line 4089) \-, and translations: See 5.11. (line 5739) \-, incompatibilities with AT&T troff: See 5.34. (line 10840) \-, used as delimiter: See 5.5.3. (line 4089) \/, used as delimiter: See 5.5.3. (line 4089) \0, used as delimiter: See 5.5.3. (line 4089) \, in \X: See 5.30. (line 10184) \, used as delimiter: See 5.5.3. (line 4089) \, when reading text for a macro: See 5.21.1. (line 8400) \, difference to \~: See 5.5.1.1. (line 3963) \, incompatibilities with AT&T troff: See 5.34. (line 10840) \, used as delimiter: See 5.5.3. (line 4089) \?, and copy-in mode <1>: See 5.25. (line 9560) \?, and copy-in mode: See 5.20.1. (line 8019) \?, in top-level diversion: See 5.25. (line 9589) \?, incompatibilities with AT&T troff: See 5.34. (line 10878) \?, used as delimiter: See 5.5.3. (line 4089) \[, and translations: See 5.11. (line 5739) \\, when reading text for a macro: See 5.21.1. (line 8400) \^, incompatibilities with AT&T troff: See 5.34. (line 10840) \^, used as delimiter: See 5.5.3. (line 4089) \_, and translations: See 5.11. (line 5739) \_, incompatibilities with AT&T troff: See 5.34. (line 10840) \_, used as delimiter: See 5.5.3. (line 4089) \`, and translations: See 5.11. (line 5739) \`, incompatibilities with AT&T troff: See 5.34. (line 10840) \`, used as delimiter: See 5.5.3. (line 4089) \A, allowed delimiters: See 5.5.3. (line 4096) \a, and copy-in mode: See 5.10.1. (line 5507) \a, and translations: See 5.11. (line 5748) \A, incompatibilities with AT&T troff: See 5.34. (line 10840) \a, used as delimiter: See 5.5.3. (line 4089) \B, allowed delimiters: See 5.5.3. (line 4096) \b, limitations: See 5.23. (line 9022) \b, possible quote characters: See 5.5.3. (line 4073) \C, allowed delimiters: See 5.5.3. (line 4096) \c, and fill mode: See 5.14. (line 6114) \c, and no-fill mode: See 5.14. (line 6104) \C, and translations: See 5.11. (line 5739) \c, incompatibilities with AT&T troff: See 5.34. (line 10840) \c, used as delimiter: See 5.5.3. (line 4089) \D'f ...' and horizontal resolution: See 5.23. (line 8930) \D, allowed delimiters: See 5.5.3. (line 4099) \d, used as delimiter: See 5.5.3. (line 4089) \E, and copy-in mode: See 5.11. (line 5656) \e, and glyph definitions: See 5.17.4. (line 6966) \e, and translations: See 5.11. (line 5743) \e, incompatibilities with AT&T troff: See 5.34. (line 10878) \e, used as delimiter: See 5.5.3. (line 4108) \E, used as delimiter: See 5.5.3. (line 4089) \e, used as delimiter: See 5.5.3. (line 4089) \F, and changing fonts: See 5.17.1. (line 6353) \F, and font positions: See 5.17.3. (line 6617) \f, and font translations: See 5.17.1. (line 6399) \f, incompatibilities with AT&T troff: See 5.34. (line 10826) \H, allowed delimiters: See 5.5.3. (line 4099) \h, allowed delimiters: See 5.5.3. (line 4099) \H, incompatibilities with AT&T troff: See 5.34. (line 10826) \H, using + and -: See 5.3. (line 3722) \H, with fractional type sizes: See 5.18.2. (line 7604) \L, allowed delimiters: See 5.5.3. (line 4099) \l, allowed delimiters: See 5.5.3. (line 4099) \L, and glyph definitions: See 5.17.4. (line 6966) \l, and glyph definitions: See 5.17.4. (line 6966) \N, allowed delimiters: See 5.5.3. (line 4099) \N, and translations: See 5.11. (line 5739) \n, and warnings: See 5.33.1. (line 10705) \n, incompatibilities with AT&T troff: See 5.34. (line 10782) \n, when reading text for a macro: See 5.21.1. (line 8400) \o, possible quote characters: See 5.5.3. (line 4073) \p, used as delimiter: See 5.5.3. (line 4089) \R, after \c: See 5.14. (line 6096) \R, allowed delimiters: See 5.5.3. (line 4099) \R, and warnings: See 5.33.1. (line 10705) \R, difference to nr: See 5.6.3. (line 4381) \r, used as delimiter: See 5.5.3. (line 4089) \R, using + and -: See 5.3. (line 3722) \S, allowed delimiters: See 5.5.3. (line 4099) \s, allowed delimiters: See 5.5.3. (line 4099) \S, incompatibilities with AT&T troff: See 5.34. (line 10826) \s, incompatibilities with AT&T troff: See 5.34. (line 10826) \s, using + and -: See 5.3. (line 3722) \s, with fractional type sizes: See 5.18.2. (line 7604) \t, and copy-in mode: See 5.10. (line 5321) \t, and translations: See 5.11. (line 5748) \t, and warnings: See 5.33.1. (line 10712) \t, used as delimiter: See 5.5.3. (line 4089) \u, used as delimiter: See 5.5.3. (line 4089) \v, allowed delimiters: See 5.5.3. (line 4099) \V, and copy-in mode: See 5.29. (line 10169) \v, internal representation: See 5.32. (line 10418) \w, allowed delimiters: See 5.5.3. (line 4096) \x, allowed delimiters: See 5.5.3. (line 4099) \X, and special characters: See 5.30. (line 10191) \X, followed by \%: See 5.8. (line 4996) \X, possible quote characters: See 5.5.3. (line 4073) \Y, followed by \%: See 5.8. (line 4996) \Z, allowed delimiters: See 5.5.3. (line 4096) \{, incompatibilities with AT&T troff: See 5.34. (line 10840) \{, used as delimiter: See 5.5.3. (line 4089) \|, incompatibilities with AT&T troff: See 5.34. (line 10840) \|, used as delimiter: See 5.5.3. (line 4089) \}, and warnings: See 5.33.1. (line 10716) \}, incompatibilities with AT&T troff: See 5.34. (line 10840) \}, used as delimiter: See 5.5.3. (line 4089) \~, and translations: See 5.11. (line 5745) \~, difference to \: See 5.5.1.1. (line 3963) \~, used as delimiter: See 5.5.3. (line 4089) ], as part of an identifier: See 5.4. (line 3781) ], at end of sentence <1>: See 5.17.4. (line 6914) ], at end of sentence: See 5.1.3. (line 3434) ], ending an identifier <1>: See 5.5.3. (line 4054) ], ending an identifier: See 5.4. (line 3816) ], macro names starting with, and refer: See 5.4. (line 3787) aborting (ab): See 5.33. (line 10517) absolute position operator (|): See 5.3. (line 3717) accent marks [ms]: See 4.3.6.5. (line 3060) access of postprocessor: See 5.30. (line 10176) accessing unnamed glyphs with \N: See 8.2.2. (line 12364) activating kerning (kern): See 5.17.8. (line 7320) activating ligatures (lg): See 5.17.8. (line 7302) activating track kerning (tkf): See 5.17.8. (line 7338) ad request, and hyphenation margin: See 5.8. (line 5108) ad request, and hyphenation space: See 5.8. (line 5123) adjusting: See 5.1.1. (line 3390) adjusting and filling, manipulating: See 5.7. (line 4638) adjustment mode register (.j): See 5.7. (line 4750) adobe glyph list (AGL): See 5.17.4. (line 6727) AGL (adobe glyph list): See 5.17.4. (line 6727) alias, diversion, creating (als): See 5.19. (line 7915) alias, diversion, removing (rm): See 5.19. (line 7950) alias, macro, creating (als): See 5.19. (line 7915) alias, macro, removing (rm): See 5.19. (line 7950) alias, number register, creating (aln): See 5.6.1. (line 4338) alias, string, creating (als): See 5.19. (line 7915) alias, string, removing (rm): See 5.19. (line 7950) als request, and \$0: See 5.21.2. (line 8490) am, am1, ami requests, and warnings: See 5.33.1. (line 10698) annotations: See 3.2.6. (line 1335) appending to a diversion (da): See 5.25. (line 9426) appending to a file (opena): See 5.29. (line 10118) appending to a macro (am): See 5.21. (line 8344) appending to a string (as): See 5.19. (line 7862) arc, drawing (\D'a ...'): See 5.23. (line 8907) argument delimiting characters: See 5.5.3. (line 4064) arguments to macros, and tabs: See 5.5.1.1. (line 3948) arguments to requests and macros: See 5.5.1.1. (line 3948) arguments, and compatibility mode: See 5.32. (line 10458) arguments, macro (\$): See 5.21.2. (line 8441) arguments, of strings: See 5.19. (line 7693) arithmetic operators: See 5.3. (line 3654) artificial fonts: See 5.17.7. (line 7149) as, as1 requests, and comments: See 5.5.3.1. (line 4133) as, as1 requests, and warnings: See 5.33.1. (line 10698) ASCII approximation output register (.A) <1>: See 5.6.5. (line 4611) ASCII approximation output register (.A): See 2.1. (line 583) ASCII, output encoding: See 2.1. (line 783) asciify request, and writem: See 5.29. (line 10140) assigning formats (af): See 5.6.4. (line 4432) assignments, indirect: See 5.6.2. (line 4351) assignments, nested: See 5.6.2. (line 4351) AT&T troff, ms macro package differences: See 4.3.7. (line 3190) auto-increment: See 5.6.3. (line 4376) auto-increment, and ig request: See 5.5.3.1. (line 4208) available glyphs, list (`groff_char(7)' man page):See 5.17.4. (line 6713) background color name register (.M): See 5.28. (line 9903) backslash, printing (\\, \e, \E, \[rs]) <1>: See 5.34. (line 10878) backslash, printing (\\, \e, \E, \[rs]): See 5.5.3. (line 4111) backspace character: See 5.4. (line 3751) backspace character, and translations: See 5.11. (line 5748) backtrace of input stack (backtrace): See 5.33. (line 10575) baseline: See 5.18. (line 7436) basic unit (u): See 5.2. (line 3564) basics of macros: See 3.1. (line 1100) bd request, and font styles: See 5.17.2. (line 6499) bd request, and font translations: See 5.17.1. (line 6399) bd request, incompatibilities with AT&T troff: See 5.34. (line 10857) begin of conditional block (\{): See 5.20.2. (line 8127) beginning diversion (di): See 5.25. (line 9426) blank line <1>: See 5.5.1. (line 3894) blank line: See 5.1.5. (line 3474) blank line (sp): See 3.1. (line 1189) blank line macro (blm) <1>: See 5.24.4. (line 9273) blank line macro (blm) <2>: See 5.5.1. (line 3894) blank line macro (blm): See 5.1.5. (line 3474) blank line traps: See 5.24.4. (line 9272) blank lines, disabling: See 5.9. (line 5301) block, conditional, begin (\{): See 5.20.2. (line 8127) block, condititional, end (\}): See 5.20.2. (line 8127) bold face [man]: See 4.1.3. (line 1659) bold face, imitating (bd): See 5.17.7. (line 7243) bottom margin: See 5.15. (line 6149) bounding box: See 5.31. (line 10355) box rule glyph (\[br]): See 5.23. (line 8826) box, boxa requests, and warnings: See 5.33.1. (line 10698) boxa request, and dn (dl): See 5.25. (line 9500) bp request, and top-level diversion: See 5.16. (line 6250) bp request, and traps (.pe): See 5.24.1. (line 9193) bp request, causing implicit linebreak: See 5.7. (line 4638) bp request, using + and -: See 5.3. (line 3722) br glyph, and cflags: See 5.17.4. (line 6910) break <1>: See 5.7. (line 4638) break: See 3.1. (line 1145) break (br): See 3.1. (line 1216) break request, in a while loop: See 5.20.3. (line 8216) break, implicit: See 5.1.5. (line 3470) built-in registers: See 5.6.5. (line 4510) bulleted list, example markup [ms]: See 4.3.5.4. (line 2554) c unit: See 5.2. (line 3585) calling convention of preprocessors: See 4.1.6. (line 1784) capabilities of groff: See 1.3. (line 401) ce request, causing implicit linebreak: See 5.7. (line 4638) ce request, difference to .ad c: See 5.7. (line 4700) centered text: See 5.7. (line 4700) centering lines (ce) <1>: See 5.7. (line 4844) centering lines (ce): See 3.1. (line 1202) centimeter unit (c): See 5.2. (line 3585) cf request, and copy-in mode: See 5.29. (line 9959) cf request, causing implicit linebreak: See 5.7. (line 4638) changing font family (fam, \F): See 5.17.2. (line 6463) changing font position (\f): See 5.17.3. (line 6617) changing font style (sty): See 5.17.2. (line 6499) changing fonts (ft, \f): See 5.17.1. (line 6353) changing format, and read-only registers: See 5.6.4. (line 4494) changing the font height (\H): See 5.17.7. (line 7159) changing the font slant (\S): See 5.17.7. (line 7190) changing the page number character (pc): See 5.15. (line 6222) changing trap location (ch): See 5.24.1. (line 9160) changing type sizes (ps, \s): See 5.18.1. (line 7463) changing vertical line spacing (vs): See 5.18.1. (line 7539) char request, and soft hyphen character: See 5.8. (line 5138) char request, and translations: See 5.11. (line 5739) char request, used with \N: See 5.17.4. (line 6839) character: See 5.17.4. (line 6640) character class (class): See 5.17.5. (line 7059) character classes: See 5.17.5. (line 7053) character properties (cflags): See 5.17.4. (line 6876) character translations: See 5.11. (line 5579) character, backspace: See 5.4. (line 3751) character, backspace, and translations: See 5.11. (line 5748) character, control (.): See 5.5.1. (line 3872) character, control, changing (cc): See 5.11. (line 5579) character, defining (char): See 5.17.4. (line 6966) character, defining fallback (fchar, fschar, schar):See 5.17.4. (line 6966) character, escape, changing (ec): See 5.11. (line 5622) character, escape, while defining glyph: See 5.17.4. (line 6966) character, field delimiting (fc): See 5.10.2. (line 5541) character, field padding (fc): See 5.10.2. (line 5541) character, hyphenation (\%): See 5.8. (line 4982) character, leader repetition (lc): See 5.10.1. (line 5512) character, leader, and translations: See 5.11. (line 5748) character, leader, non-interpreted (\a): See 5.10.1. (line 5507) character, named (\C): See 5.17.4. (line 6823) character, newline: See 5.5.3. (line 4106) character, newline, and translations: See 5.11. (line 5748) character, no-break control ('): See 5.5.1. (line 3872) character, no-break control, changing (c2): See 5.11. (line 5579) character, soft hyphen, setting (shc): See 5.8. (line 5138) character, space: See 5.5.3. (line 4106) character, special: See 5.11. (line 5739) character, tab: See 5.5.3. (line 4106) character, tab repetition (tc): See 5.10. (line 5450) character, tab, and translations: See 5.11. (line 5748) character, tab, non-interpreted (\t): See 5.10. (line 5321) character, tabulator: See 5.1.4. (line 3446) character, transparent <1>: See 5.17.4. (line 6914) character, transparent: See 5.1.3. (line 3434) character, whitespace: See 5.4. (line 3749) character, zero width space (\&) <1>: See 5.23. (line 8807) character, zero width space (\&) <2>: See 5.17.8. (line 7325) character, zero width space (\&): See 5.5.1. (line 3915) characters, argument delimiting: See 5.5.3. (line 4064) characters, end-of-sentence: See 5.17.4. (line 6886) characters, hyphenation: See 5.17.4. (line 6890) characters, input, and output glyphs, compatibility with AT&T troff:See 5.34. (line 10857) characters, invalid for trf request: See 5.29. (line 9982) characters, invalid input: See 5.4. (line 3754) characters, overlapping: See 5.17.4. (line 6904) characters, special: See 7.1. (line 10966) characters, unnamed, accessing with \N: See 8.2.2. (line 12364) chem, the program: See 6.6. (line 10939) circle, drawing (\D'c ...'): See 5.23. (line 8888) circle, solid, drawing (\D'C ...'): See 5.23. (line 8893) class of characters (class): See 5.17.5. (line 7059) classes, character: See 5.17.5. (line 7053) closing file (close): See 5.29. (line 10149) code, hyphenation (hcode): See 5.8. (line 5073) color name, background, register (.M): See 5.28. (line 9903) color name, drawing, register (.m): See 5.28. (line 9873) color name, fill, register (.M): See 5.28. (line 9903) color, default: See 5.28. (line 9828) colors: See 5.28. (line 9809) colors, fill, unnamed (\D'F...'): See 5.23. (line 8997) command prefix: See 2.2. (line 868) command-line options: See 2.1. (line 582) commands, embedded: See 5.5. (line 3857) comments: See 5.5.3.1. (line 4123) comments in font files: See 8.2.2. (line 12349) comments, lining up with tabs: See 5.5.3.1. (line 4138) comments, with ds: See 5.19. (line 7720) common features: See 3.2. (line 1229) common name space of macros, diversions, and strings:See 5.19. (line 7772) comparison of strings: See 5.20.1. (line 8010) comparison operators: See 5.3. (line 3661) compatibility mode <1>: See 5.34. (line 10774) compatibility mode: See 5.33.1. (line 10734) compatibility mode, and parameters: See 5.32. (line 10458) composite glyph names: See 5.17.4. (line 6727) conditional block, begin (\{): See 5.20.2. (line 8127) conditional block, end (\}): See 5.20.2. (line 8127) conditional output for terminal (TTY): See 5.20.1. (line 7976) conditional page break (ne): See 5.16. (line 6259) conditionals and loops: See 5.20. (line 7965) consecutive hyphenated lines (hlm): See 5.8. (line 4944) constant glyph space mode (cs): See 5.17.7. (line 7272) contents, table of <1>: See 5.10.1. (line 5519) contents, table of: See 3.2.7. (line 1350) continuation, input line (\): See 5.14. (line 6079) continuation, output line (\c): See 5.14. (line 6079) continue request, in a while loop: See 5.20.3. (line 8216) continuous underlining (cu): See 5.17.7. (line 7232) control character (.): See 5.5.1. (line 3872) control character, changing (cc): See 5.11. (line 5579) control character, no-break ('): See 5.5.1. (line 3872) control character, no-break, changing (c2): See 5.11. (line 5579) control sequences, for terminals: See 7.2.1. (line 11023) control, line: See 5.14. (line 6046) control, page: See 5.16. (line 6231) conventions for input: See 5.1.6. (line 3494) copy mode: See 5.21.1. (line 8400) copy-in mode: See 5.21.1. (line 8400) copy-in mode, and \!: See 5.25. (line 9560) copy-in mode, and \? <1>: See 5.25. (line 9560) copy-in mode, and \?: See 5.20.1. (line 8019) copy-in mode, and \a: See 5.10.1. (line 5507) copy-in mode, and \E: See 5.11. (line 5656) copy-in mode, and \t: See 5.10. (line 5321) copy-in mode, and \V: See 5.29. (line 10169) copy-in mode, and cf request: See 5.29. (line 9959) copy-in mode, and device request: See 5.30. (line 10188) copy-in mode, and ig request: See 5.5.3.1. (line 4208) copy-in mode, and length request: See 5.19. (line 7895) copy-in mode, and macro arguments: See 5.21.2. (line 8441) copy-in mode, and output request: See 5.25. (line 9592) copy-in mode, and tm request: See 5.33. (line 10507) copy-in mode, and tm1 request: See 5.33. (line 10507) copy-in mode, and tmc request: See 5.33. (line 10507) copy-in mode, and trf request: See 5.29. (line 9959) copy-in mode, and write request: See 5.29. (line 10130) copy-in mode, and writec request: See 5.29. (line 10130) copy-in mode, and writem request: See 5.29. (line 10143) copying environment (evc): See 5.26. (line 9709) correction between italic and roman glyph (\/, \,):See 5.17.8. (line 7358) correction, italic (\/): See 5.17.8. (line 7358) correction, left italic (\,): See 5.17.8. (line 7370) cover page macros, [ms]: See 4.3.4. (line 2246) cp request, and glyph definitions: See 5.17.4. (line 6966) cp1047, input encoding: See 5.1.7. (line 3515) cp1047, output encoding: See 2.1. (line 795) creating alias, for diversion (als): See 5.19. (line 7915) creating alias, for macro (als): See 5.19. (line 7915) creating alias, for number register (aln): See 5.6.1. (line 4338) creating alias, for string (als): See 5.19. (line 7915) creating new characters (char): See 5.17.4. (line 6966) credits: See 1.7. (line 501) cs request, and font styles: See 5.17.2. (line 6499) cs request, and font translations: See 5.17.1. (line 6399) cs request, incompatibilities with AT&T troff: See 5.34. (line 10857) cs request, with fractional type sizes: See 5.18.2. (line 7604) current directory: See 2.3. (line 930) current input file name register (.F): See 5.6.5. (line 4516) current page number (%): See 5.16. (line 6253) current time: See 5.29. (line 10090) current time, hours (hours): See 5.6.5. (line 4543) current time, minutes (minutes): See 5.6.5. (line 4539) current time, seconds (seconds): See 5.6.5. (line 4534) current vertical position (nl): See 5.16. (line 6293) da request, and dn (dl): See 5.25. (line 9500) da request, and warnings: See 5.33.1. (line 10693) date, day of the month register (dy): See 5.6.5. (line 4550) date, day of the week register (dw): See 5.6.5. (line 4547) date, month of the year register (mo): See 5.6.5. (line 4553) date, year register (year, yr): See 5.6.5. (line 4556) day of the month register (dy): See 5.6.5. (line 4550) day of the week register (dw): See 5.6.5. (line 4547) de request, and while: See 5.20.3. (line 8166) de, de1, dei requests, and warnings: See 5.33.1. (line 10698) debugging: See 5.33. (line 10483) default color: See 5.28. (line 9828) default indentation [man]: See 4.1.4. (line 1704) default indentation, resetting [man]: See 4.1.2. (line 1645) default units: See 5.2.1. (line 3626) defining character (char): See 5.17.4. (line 6966) defining character class (class): See 5.17.5. (line 7059) defining fallback character (fchar, fschar, schar):See 5.17.4. (line 6966) defining glyph (char): See 5.17.4. (line 6966) defining symbol (char): See 5.17.4. (line 6966) delayed text: See 3.2.6. (line 1339) delimited arguments, incompatibilities with AT&T troff:See 5.34. (line 10816) delimiting character, for fields (fc): See 5.10.2. (line 5541) delimiting characters for arguments: See 5.5.3. (line 4064) depth, of last glyph (.cdp): See 5.26. (line 9734) DESC file, format: See 8.2.1. (line 12175) device request, and copy-in mode: See 5.30. (line 10188) device resolution: See 8.2.1. (line 12256) devices for output <1>: See 7. (line 10963) devices for output: See 1.6. (line 492) dg glyph, at end of sentence <1>: See 5.17.4. (line 6914) dg glyph, at end of sentence: See 5.1.3. (line 3434) di request, and warnings: See 5.33.1. (line 10693) differences in implementation: See 5.34. (line 10774) digit width space (\0): See 5.22. (line 8675) digits, and delimiters: See 5.5.3. (line 4102) dimensions, line: See 5.13. (line 5878) directories for fonts: See 2.4. (line 951) directories for macros: See 2.3. (line 915) directory, current: See 2.3. (line 930) directory, for tmac files: See 2.3. (line 920) directory, home: See 2.3. (line 933) directory, platform-specific: See 2.3. (line 935) directory, site-specific <1>: See 2.4. (line 974) directory, site-specific: See 2.3. (line 935) disabling \ (eo): See 5.11. (line 5597) disabling hyphenation (\%): See 5.8. (line 4982) discardable horizontal space: See 5.7. (line 4821) discarded space in traps: See 5.9. (line 5225) displays: See 3.2.5. (line 1309) displays [ms]: See 4.3.5.7. (line 2724) displays, and footnotes [ms]: See 4.3.5.10. (line 2892) distance to next trap register (.t): See 5.24.1. (line 9151) ditroff, the program: See 1.2. (line 349) diversion name register (.z): See 5.25. (line 9475) diversion trap, setting (dt): See 5.24.2. (line 9229) diversion traps: See 5.24.2. (line 9228) diversion, appending (da): See 5.25. (line 9426) diversion, beginning (di): See 5.25. (line 9426) diversion, creating alias (als): See 5.19. (line 7915) diversion, ending (di): See 5.25. (line 9426) diversion, nested: See 5.25. (line 9475) diversion, removing (rm): See 5.19. (line 7910) diversion, removing alias (rm): See 5.19. (line 7950) diversion, renaming (rn): See 5.19. (line 7907) diversion, stripping final newline: See 5.19. (line 7842) diversion, top-level: See 5.25. (line 9416) diversion, top-level, and \!: See 5.25. (line 9584) diversion, top-level, and \?: See 5.25. (line 9589) diversion, top-level, and bp: See 5.16. (line 6250) diversion, unformatting (asciify): See 5.25. (line 9608) diversion, vertical position in, register (.d):See 5.25. (line 9475) diversions: See 5.25. (line 9410) diversions, and traps: See 5.24.1. (line 9217) diversions, shared name space with macros and strings:See 5.19. (line 7772) dl register, and da (boxa): See 5.25. (line 9500) dn register, and da (boxa): See 5.25. (line 9500) documents, multi-file: See 5.33. (line 10487) documents, structuring the source code: See 5.5.1. (line 3880) double quote, in a macro argument: See 5.5.1.1. (line 3968) double-spacing (ls) <1>: See 5.9. (line 5238) double-spacing (ls): See 3.1. (line 1179) double-spacing (vs, pvs): See 5.18.1. (line 7576) drawing a circle (\D'c ...'): See 5.23. (line 8888) drawing a line (\D'l ...'): See 5.23. (line 8858) drawing a polygon (\D'p ...'): See 5.23. (line 8937) drawing a solid circle (\D'C ...'): See 5.23. (line 8893) drawing a solid ellipse (\D'E ...'): See 5.23. (line 8903) drawing a solid polygon (\D'P ...'): See 5.23. (line 8946) drawing a spline (\D'~ ...'): See 5.23. (line 8915) drawing an arc (\D'a ...'): See 5.23. (line 8907) drawing an ellipse (\D'e ...'): See 5.23. (line 8897) drawing color name register (.m): See 5.28. (line 9873) drawing horizontal lines (\l): See 5.23. (line 8792) drawing requests: See 5.23. (line 8781) drawing vertical lines (\L): See 5.23. (line 8826) ds request, and comments: See 5.19. (line 7720) ds request, and double quotes: See 5.5.1.1. (line 4015) ds request, and leading spaces: See 5.19. (line 7734) ds, ds1 requests, and comments: See 5.5.3.1. (line 4133) ds, ds1 requests, and warnings: See 5.33.1. (line 10698) dumping environments (pev): See 5.33. (line 10541) dumping number registers (pnr): See 5.33. (line 10556) dumping symbol table (pm): See 5.33. (line 10545) dumping traps (ptr): See 5.33. (line 10560) EBCDIC encoding: See 5.1.4. (line 3446) EBCDIC encoding of a tab: See 5.10. (line 5317) EBCDIC encoding of backspace: See 5.4. (line 3751) EBCDIC, input encoding: See 5.1.7. (line 3515) EBCDIC, output encoding: See 2.1. (line 795) el request, and warnings: See 5.33.1. (line 10676) ellipse, drawing (\D'e ...'): See 5.23. (line 8897) ellipse, solid, drawing (\D'E ...'): See 5.23. (line 8903) em glyph, and cflags: See 5.17.4. (line 6897) em unit (m): See 5.2. (line 3607) embedded commands: See 5.5. (line 3857) embedding PDF: See 7.4.2. (line 11163) embedding PostScript: See 7.3.2. (line 11095) embolding of special fonts: See 5.17.7. (line 7261) empty line: See 5.1.5. (line 3474) empty line (sp): See 3.1. (line 1189) empty space before a paragraph [man]: See 4.1.4. (line 1713) en unit (n): See 5.2. (line 3612) enabling vertical position traps (vpt): See 5.24.1. (line 9059) encoding, EBCDIC: See 5.1.4. (line 3446) encoding, input, cp1047: See 5.1.7. (line 3515) encoding, input, EBCDIC: See 5.1.7. (line 3515) encoding, input, latin-1 (ISO 8859-1): See 5.1.7. (line 3520) encoding, input, latin-2 (ISO 8859-2): See 5.1.7. (line 3524) encoding, input, latin-5 (ISO 8859-9): See 5.1.7. (line 3529) encoding, input, latin-9 (latin-0, ISO 8859-15):See 5.1.7. (line 3534) encoding, output, ASCII: See 2.1. (line 783) encoding, output, cp1047: See 2.1. (line 795) encoding, output, EBCDIC: See 2.1. (line 795) encoding, output, latin-1 (ISO 8859-1): See 2.1. (line 787) encoding, output, utf-8: See 2.1. (line 791) end of conditional block (\}): See 5.20.2. (line 8127) end-of-input macro (em): See 5.24.6. (line 9309) end-of-input trap, setting (em): See 5.24.6. (line 9309) end-of-input traps: See 5.24.6. (line 9308) end-of-sentence characters: See 5.17.4. (line 6886) ending diversion (di): See 5.25. (line 9426) environment number/name register (.ev): See 5.26. (line 9676) environment variables: See 2.2. (line 860) environment, copying (evc): See 5.26. (line 9709) environment, dimensions of last glyph (.w, .cht, .cdp, .csk):See 5.26. (line 9734) environment, previous line length (.n): See 5.26. (line 9749) environment, switching (ev): See 5.26. (line 9676) environments: See 5.26. (line 9643) environments, dumping (pev): See 5.33. (line 10541) eqn, the program: See 6.1. (line 10907) equations [ms]: See 4.3.5.8. (line 2820) escape character, changing (ec): See 5.11. (line 5622) escape character, while defining glyph: See 5.17.4. (line 6966) escapes: See 5.5.3. (line 4040) escaping newline characters, in strings: See 5.19. (line 7741) ex request, use in debugging: See 5.33. (line 10522) ex request, used with nx and rd: See 5.29. (line 10035) example markup, bulleted list [ms]: See 4.3.5.4. (line 2554) example markup, glossary-style list [ms]: See 4.3.5.4. (line 2602) example markup, multi-page table [ms]: See 4.3.5.9. (line 2855) example markup, numbered list [ms]: See 4.3.5.4. (line 2576) example markup, title page: See 4.3.4. (line 2307) examples of invocation: See 2.6. (line 1018) exiting (ex): See 5.33. (line 10522) expansion of strings (\*): See 5.19. (line 7693) explicit hyphen (\%): See 5.8. (line 4944) expression, limitation of logical not in: See 5.3. (line 3673) expression, order of evaluation: See 5.3. (line 3706) expressions: See 5.3. (line 3652) expressions, and space characters: See 5.3. (line 3733) extra post-vertical line space (\x): See 5.18.1. (line 7569) extra post-vertical line space register (.a): See 5.9. (line 5269) extra pre-vertical line space (\x): See 5.18.1. (line 7560) extra spaces: See 5.1.1. (line 3394) extremum operators (>?, : See 5.33.1. (line 10667) fill mode <2>: See 5.7. (line 4795) fill mode: See 5.1.5. (line 3479) fill mode (fi): See 5.7. (line 4663) fill mode, and \c: See 5.14. (line 6114) filling: See 5.1.1. (line 3390) filling and adjusting, manipulating: See 5.7. (line 4638) final newline, stripping in diversions: See 5.19. (line 7842) fl request, causing implicit linebreak: See 5.7. (line 4638) floating keep: See 3.2.5. (line 1326) flush output (fl): See 5.33. (line 10566) font description file, format <1>: See 8.2.2. (line 12319) font description file, format: See 8.2.1. (line 12175) font directories: See 2.4. (line 951) font families: See 5.17.2. (line 6444) font family, changing (fam, \F): See 5.17.2. (line 6463) font file, format: See 8.2.2. (line 12319) font files: See 8.2. (line 12162) font files, comments: See 8.2.2. (line 12349) font for underlining (uf): See 5.17.7. (line 7236) font height, changing (\H): See 5.17.7. (line 7159) font path: See 2.4. (line 959) font position register (.f): See 5.17.3. (line 6575) font position, changing (\f): See 5.17.3. (line 6617) font positions: See 5.17.3. (line 6562) font selection [man]: See 4.1.3. (line 1651) font slant, changing (\S): See 5.17.7. (line 7190) font style, changing (sty): See 5.17.2. (line 6499) font styles: See 5.17.2. (line 6444) font translation (ftr): See 5.17.1. (line 6399) font, magnification (fzoom): See 5.17.1. (line 6416) font, mounting (fp): See 5.17.3. (line 6569) font, optical size: See 5.17.1. (line 6416) font, previous (ft, \f[], \fP): See 5.17.1. (line 6365) font, zoom factor (fzoom): See 5.17.1. (line 6416) fonts <1>: See 5.17.1. (line 6348) fonts: See 5.17. (line 6338) fonts, artificial: See 5.17.7. (line 7149) fonts, changing (ft, \f): See 5.17.1. (line 6353) fonts, PostScript: See 5.17.2. (line 6449) fonts, searching: See 2.4. (line 951) fonts, special: See 5.17.6. (line 7119) footers <1>: See 5.24.1. (line 9079) footers: See 5.15. (line 6160) footers [ms]: See 4.3.6.1. (line 2912) footnotes: See 3.2.6. (line 1335) footnotes [ms]: See 4.3.5.10. (line 2874) footnotes, and displays [ms]: See 4.3.5.10. (line 2892) footnotes, and keeps [ms]: See 4.3.5.10. (line 2892) form letters: See 5.29. (line 10018) format of font description file: See 8.2.1. (line 12175) format of font description files: See 8.2.2. (line 12319) format of font files: See 8.2.2. (line 12319) format of register (\g): See 5.6.4. (line 4502) formats, assigning (af): See 5.6.4. (line 4432) formats, file: See 8. (line 11429) fp request, and font translations: See 5.17.1. (line 6399) fp request, incompatibilities with AT&T troff: See 5.34. (line 10857) fractional point sizes <1>: See 5.34. (line 10847) fractional point sizes: See 5.18.2. (line 7604) fractional type sizes <1>: See 5.34. (line 10847) fractional type sizes: See 5.18.2. (line 7604) french-spacing: See 5.1.3. (line 3427) fspecial request, and font styles: See 5.17.2. (line 6499) fspecial request, and font translations: See 5.17.1. (line 6399) fspecial request, and glyph search order: See 5.17.4. (line 6648) fspecial request, and imitating bold: See 5.17.7. (line 7261) ft request, and font translations: See 5.17.1. (line 6399) gchem, invoking: See 6.6.1. (line 10942) gchem, the program: See 6.6. (line 10939) geqn, invoking: See 6.1.1. (line 10910) geqn, the program: See 6.1. (line 10907) GGL (groff glyph list) <1>: See 5.17.5. (line 7080) GGL (groff glyph list): See 5.17.4. (line 6727) ggrn, invoking: See 6.4.1. (line 10928) ggrn, the program: See 6.4. (line 10925) glossary-style list, example markup [ms]: See 4.3.5.4. (line 2602) glyph: See 5.17.4. (line 6640) glyph for line drawing: See 5.23. (line 8826) glyph names, composite: See 5.17.4. (line 6727) glyph pile (\b): See 5.23. (line 9014) glyph properties (cflags): See 5.17.4. (line 6876) glyph, box rule (\[br]): See 5.23. (line 8826) glyph, constant space: See 5.17.7. (line 7272) glyph, defining (char): See 5.17.4. (line 6966) glyph, for line drawing: See 5.23. (line 8803) glyph, for margins (mc): See 5.31. (line 10286) glyph, italic correction (\/): See 5.17.8. (line 7358) glyph, last, dimensions (.w, .cht, .cdp, .csk):See 5.26. (line 9734) glyph, leader repetition (lc): See 5.10.1. (line 5512) glyph, left italic correction (\,): See 5.17.8. (line 7370) glyph, numbered (\N) <1>: See 5.17.4. (line 6839) glyph, numbered (\N): See 5.11. (line 5739) glyph, removing definition (rchar, rfschar): See 5.17.4. (line 7023) glyph, soft hyphen (hy): See 5.8. (line 5138) glyph, tab repetition (tc): See 5.10. (line 5450) glyph, underscore (\[ru]): See 5.23. (line 8803) glyphs, available, list (`groff_char(7)' man page):See 5.17.4. (line 6713) glyphs, output, and input characters, compatibility with AT&T troff:See 5.34. (line 10857) glyphs, overstriking (\o): See 5.22. (line 8754) glyphs, unnamed: See 5.17.4. (line 6850) glyphs, unnamed, accessing with \N: See 8.2.2. (line 12364) GNU-specific register (.g): See 5.6.5. (line 4607) gpic, invoking: See 6.3.1. (line 10922) gpic, the program: See 6.3. (line 10919) grap, the program: See 6.5. (line 10931) gray shading (\D'f ...'): See 5.23. (line 8920) grefer, invoking: See 6.7.1. (line 10948) grefer, the program: See 6.7. (line 10945) grn, the program: See 6.4. (line 10925) grodvi, invoking: See 7.5.1. (line 11184) grodvi, the program: See 7.5. (line 11177) groff - what is it?: See 1.1. (line 261) groff capabilities: See 1.3. (line 401) groff glyph list (GGL) <1>: See 5.17.5. (line 7080) groff glyph list (GGL): See 5.17.4. (line 6727) groff invocation: See 2. (line 514) groff, and pi request: See 5.29. (line 10074) GROFF_BIN_PATH, environment variable: See 2.2. (line 864) GROFF_COMMAND_PREFIX, environment variable: See 2.2. (line 868) GROFF_ENCODING, environment variable: See 2.2. (line 879) GROFF_FONT_PATH, environment variable <1>: See 2.4. (line 971) GROFF_FONT_PATH, environment variable: See 2.2. (line 888) GROFF_TMAC_PATH, environment variable <1>: See 2.3. (line 927) GROFF_TMAC_PATH, environment variable: See 2.2. (line 893) GROFF_TMPDIR, environment variable: See 2.2. (line 898) GROFF_TYPESETTER, environment variable: See 2.2. (line 906) grohtml, invoking: See 7.8.1. (line 11316) grohtml, registers and strings: See 7.8.2. (line 11392) grohtml, the program <1>: See 7.8. (line 11289) grohtml, the program: See 2.1. (line 806) grolbp, invoking: See 7.7.1. (line 11256) grolbp, the program: See 7.7. (line 11249) grolj4, invoking: See 7.6.1. (line 11219) grolj4, the program: See 7.6. (line 11212) gropdf, invoking: See 7.4.1. (line 11120) gropdf, the program: See 7.4. (line 11113) grops, invoking: See 7.3.1. (line 11044) grops, the program: See 7.3. (line 11037) grotty, invoking: See 7.2.1. (line 10978) grotty, the program: See 7.2. (line 10971) gsoelim, invoking: See 6.8.1. (line 10954) gsoelim, the program: See 6.8. (line 10951) gtbl, invoking: See 6.2.1. (line 10916) gtbl, the program: See 6.2. (line 10913) gtroff, identification register (.g): See 5.6.5. (line 4607) gtroff, interactive use: See 5.33. (line 10566) gtroff, output: See 8.1. (line 11435) gtroff, process ID register ($$): See 5.6.5. (line 4604) gtroff, reference: See 5. (line 3369) gxditview, invoking: See 7.9.1. (line 11426) gxditview, the program: See 7.9. (line 11423) hanging indentation [man]: See 4.1.2. (line 1616) hcode request, and glyph definitions: See 5.17.4. (line 6966) headers <1>: See 5.24.1. (line 9079) headers: See 5.15. (line 6160) headers [ms]: See 4.3.6.1. (line 2912) height, font, changing (\H): See 5.17.7. (line 7159) height, of last glyph (.cht): See 5.26. (line 9734) high-water mark register (.h): See 5.25. (line 9482) history: See 1.2. (line 297) home directory: See 2.3. (line 933) horizontal discardable space: See 5.7. (line 4821) horizontal input line position register (hp): See 5.22. (line 8747) horizontal input line position, saving (\k): See 5.22. (line 8741) horizontal line, drawing (\l): See 5.23. (line 8792) horizontal motion (\h): See 5.22. (line 8640) horizontal output line position register (.k): See 5.22. (line 8750) horizontal resolution: See 8.2.1. (line 12194) horizontal resolution register (.H): See 5.6.5. (line 4519) horizontal space (\h): See 5.22. (line 8640) horizontal space, unformatting: See 5.19. (line 7842) hours, current time (hours): See 5.6.5. (line 4543) hpf request, and hyphenation language: See 5.8. (line 5152) hw request, and hyphenation language: See 5.8. (line 5152) hy glyph, and cflags: See 5.17.4. (line 6897) hyphen, explicit (\%): See 5.8. (line 4944) hyphenated lines, consecutive (hlm): See 5.8. (line 4944) hyphenating characters: See 5.17.4. (line 6890) hyphenation: See 5.1.2. (line 3406) hyphenation character (\%): See 5.8. (line 4982) hyphenation code (hcode): See 5.8. (line 5073) hyphenation language register (.hla): See 5.8. (line 5159) hyphenation margin (hym): See 5.8. (line 5108) hyphenation margin register (.hym): See 5.8. (line 5118) hyphenation patterns (hpf): See 5.8. (line 5013) hyphenation restrictions register (.hy): See 5.8. (line 4927) hyphenation space (hys): See 5.8. (line 5123) hyphenation space register (.hys): See 5.8. (line 5134) hyphenation, disabling (\%): See 5.8. (line 4982) hyphenation, manipulating: See 5.8. (line 4903) i unit: See 5.2. (line 3580) i/o: See 5.29. (line 9914) IBM cp1047 input encoding: See 5.1.7. (line 3515) IBM cp1047 output encoding: See 2.1. (line 795) identifiers: See 5.4. (line 3745) identifiers, undefined: See 5.4. (line 3820) ie request, and font translations: See 5.17.1. (line 6399) ie request, and warnings: See 5.33.1. (line 10676) ie request, operators to use with: See 5.20.1. (line 7968) if request, and font translations: See 5.17.1. (line 6399) if request, and the ! operator: See 5.3. (line 3667) if request, operators to use with: See 5.20.1. (line 7968) if-else: See 5.20.2. (line 8095) ig request, and auto-increment: See 5.5.3.1. (line 4208) ig request, and copy-in mode: See 5.5.3.1. (line 4208) imitating bold face (bd): See 5.17.7. (line 7243) implementation differences: See 5.34. (line 10774) implicit breaks of lines: See 5.1.5. (line 3470) implicit line breaks: See 5.1.5. (line 3470) in request, causing implicit linebreak: See 5.7. (line 4638) in request, using + and -: See 5.3. (line 3722) inch unit (i): See 5.2. (line 3580) including a file (so): See 5.29. (line 9917) incompatibilities with AT&T troff: See 5.34. (line 10774) increment value without changing the register: See 5.6.3. (line 4423) increment, automatic: See 5.6.3. (line 4376) indentaion, resetting to default [man]: See 4.1.2. (line 1645) indentation (in): See 5.13. (line 5898) index, in macro package: See 3.2.8. (line 1360) indicator, scaling: See 5.2. (line 3564) indirect assignments: See 5.6.2. (line 4351) input and output requests: See 5.29. (line 9914) input characters and output glyphs, compatibility with AT&T troff:See 5.34. (line 10857) input characters, invalid: See 5.4. (line 3754) input conventions: See 5.1.6. (line 3494) input encoding, cp1047: See 5.1.7. (line 3515) input encoding, EBCDIC: See 5.1.7. (line 3515) input encoding, latin-1 (ISO 8859-1): See 5.1.7. (line 3520) input encoding, latin-2 (ISO 8859-2): See 5.1.7. (line 3524) input encoding, latin-2 (ISO 8859-9): See 5.1.7. (line 3529) input encoding, latin-9 (latin-9, ISO 8859-15):See 5.1.7. (line 3534) input file name, current, register (.F): See 5.6.5. (line 4516) input level in delimited arguments: See 5.34. (line 10816) input line continuation (\): See 5.14. (line 6079) input line number register (.c, c.): See 5.6.5. (line 4582) input line number, setting (lf): See 5.33. (line 10487) input line position, horizontal, saving (\k): See 5.22. (line 8741) input line trap, setting (it): See 5.24.3. (line 9244) input line traps: See 5.24.3. (line 9242) input line traps and interrupted lines (itc): See 5.24.3. (line 9261) input line, horizontal position, register (hp):See 5.22. (line 8747) input stack, backtrace (backtrace): See 5.33. (line 10575) input stack, setting limit: See 5.33. (line 10600) input token: See 5.32. (line 10371) input, 8-bit: See 8.2.2. (line 12364) input, standard, reading from (rd): See 5.29. (line 9998) inserting horizontal space (\h): See 5.22. (line 8640) installation: See 9. (line 12469) interactive use of gtroff: See 5.33. (line 10566) intermediate output: See 8.1. (line 11445) interpolating registers (\n): See 5.6.2. (line 4346) interpolation of strings (\*): See 5.19. (line 7693) interrupted line: See 5.14. (line 6079) interrupted line register (.int): See 5.14. (line 6128) interrupted lines and input line traps (itc): See 5.24.3. (line 9261) introduction: See 1. (line 254) invalid characters for trf request: See 5.29. (line 9982) invalid input characters: See 5.4. (line 3754) invocation examples: See 2.6. (line 1018) invoking gchem: See 6.6.1. (line 10942) invoking geqn: See 6.1.1. (line 10910) invoking ggrn: See 6.4.1. (line 10928) invoking gpic: See 6.3.1. (line 10922) invoking grefer: See 6.7.1. (line 10948) invoking grodvi: See 7.5.1. (line 11184) invoking groff: See 2. (line 514) invoking grohtml: See 7.8.1. (line 11316) invoking grolbp: See 7.7.1. (line 11256) invoking grolj4: See 7.6.1. (line 11219) invoking gropdf: See 7.4.1. (line 11120) invoking grops: See 7.3.1. (line 11044) invoking grotty: See 7.2.1. (line 10978) invoking gsoelim: See 6.8.1. (line 10954) invoking gtbl: See 6.2.1. (line 10916) invoking gxditview: See 7.9.1. (line 11426) invoking preconv: See 6.9.1. (line 10960) ISO 6249 SGR: See 7.2.1. (line 11023) ISO 8859-1 (latin-1), input encoding: See 5.1.7. (line 3520) ISO 8859-1 (latin-1), output encoding: See 2.1. (line 787) ISO 8859-15 (latin-9, latin-0), input encoding:See 5.1.7. (line 3534) ISO 8859-2 (latin-2), input encoding: See 5.1.7. (line 3524) ISO 8859-9 (latin-2), input encoding: See 5.1.7. (line 3529) italic correction (\/): See 5.17.8. (line 7358) italic fonts [man]: See 4.1.3. (line 1698) italic glyph, correction after roman glyph (\,):See 5.17.8. (line 7370) italic glyph, correction before roman glyph (\/):See 5.17.8. (line 7358) justifying text: See 5.7. (line 4638) justifying text (rj): See 5.7. (line 4893) keep: See 3.2.5. (line 1321) keep, floating: See 3.2.5. (line 1326) keeps [ms]: See 4.3.5.7. (line 2724) keeps, and footnotes [ms]: See 4.3.5.10. (line 2892) kerning and ligatures: See 5.17.8. (line 7284) kerning enabled register (.kern): See 5.17.8. (line 7320) kerning, activating (kern): See 5.17.8. (line 7320) kerning, track: See 5.17.8. (line 7331) landscape page orientation: See 2.5. (line 988) last glyph, dimensions (.w, .cht, .cdp, .csk): See 5.26. (line 9734) last-requested point size registers (.psr, .sr):See 5.18.2. (line 7641) latin-1 (ISO 8859-1), input encoding: See 5.1.7. (line 3520) latin-1 (ISO 8859-1), output encoding: See 2.1. (line 787) latin-2 (ISO 8859-2), input encoding: See 5.1.7. (line 3524) latin-2 (ISO 8859-9), input encoding: See 5.1.7. (line 3529) latin-9 (latin-0, ISO 8859-15), input encoding:See 5.1.7. (line 3534) layout, line: See 5.13. (line 5878) layout, page: See 5.15. (line 6135) lc request, and glyph definitions: See 5.17.4. (line 6966) leader character: See 5.10.1. (line 5501) leader character, and translations: See 5.11. (line 5748) leader character, non-interpreted (\a): See 5.10.1. (line 5507) leader repetition character (lc): See 5.10.1. (line 5512) leaders: See 5.10.1. (line 5495) leading: See 5.18. (line 7445) leading spaces: See 5.1.1. (line 3394) leading spaces macro (lsm) <1>: See 5.24.5. (line 9282) leading spaces macro (lsm): See 5.1.5. (line 3479) leading spaces traps: See 5.24.5. (line 9279) leading spaces with ds: See 5.19. (line 7734) left italic correction (\,): See 5.17.8. (line 7370) left margin (po): See 5.13. (line 5894) left margin, how to move [man]: See 4.1.2. (line 1624) length of a string (length): See 5.19. (line 7895) length of line (ll): See 5.13. (line 5902) length of page (pl): See 5.15. (line 6142) length of previous line (.n): See 5.26. (line 9749) length of title line (lt): See 5.15. (line 6196) length request, and copy-in mode: See 5.19. (line 7895) letters, form: See 5.29. (line 10018) level of warnings (warn): See 5.33. (line 10637) ligature: See 5.17.4. (line 6640) ligatures and kerning: See 5.17.8. (line 7284) ligatures enabled register (.lg): See 5.17.8. (line 7302) ligatures, activating (lg): See 5.17.8. (line 7302) limitations of \b escape: See 5.23. (line 9022) line break <1>: See 5.7. (line 4638) line break <2>: See 5.1.5. (line 3470) line break: See 3.1. (line 1145) line break (br): See 3.1. (line 1216) line breaks, with vertical space [man]: See 4.1.2. (line 1638) line breaks, without vertical space [man]: See 4.1.2. (line 1642) line control: See 5.14. (line 6046) line dimensions: See 5.13. (line 5878) line drawing glyph: See 5.23. (line 8803) line indentation (in): See 5.13. (line 5898) line layout: See 5.13. (line 5878) line length (ll): See 5.13. (line 5902) line length register (.l): See 5.13. (line 6035) line length, previous (.n): See 5.26. (line 9749) line number, input, register (.c, c.): See 5.6.5. (line 4582) line number, output, register (ln): See 5.6.5. (line 4587) line numbers, printing (nm): See 5.31. (line 10220) line space, extra post-vertical (\x): See 5.18.1. (line 7569) line space, extra pre-vertical (\x): See 5.18.1. (line 7560) line spacing register (.L): See 5.9. (line 5250) line spacing, post-vertical (pvs): See 5.18.1. (line 7573) line thickness (\D't ...'): See 5.23. (line 8987) line, blank: See 5.1.5. (line 3474) line, drawing (\D'l ...'): See 5.23. (line 8858) line, empty (sp): See 3.1. (line 1189) line, horizontal, drawing (\l): See 5.23. (line 8792) line, implicit breaks: See 5.1.5. (line 3470) line, input, continuation (\): See 5.14. (line 6079) line, input, horizontal position, register (hp):See 5.22. (line 8747) line, input, horizontal position, saving (\k): See 5.22. (line 8741) line, interrupted: See 5.14. (line 6079) line, output, continuation (\c): See 5.14. (line 6079) line, output, horizontal position, register (.k):See 5.22. (line 8750) line, vertical, drawing (\L): See 5.23. (line 8826) line-tabs mode: See 5.10. (line 5459) lines, blank, disabling: See 5.9. (line 5301) lines, centering (ce) <1>: See 5.7. (line 4844) lines, centering (ce): See 3.1. (line 1202) lines, consecutive hyphenated (hlm): See 5.8. (line 4944) lines, interrupted, and input line traps (itc):See 5.24.3. (line 9261) list: See 3.2.5. (line 1316) list of available glyphs (`groff_char(7)' man page):See 5.17.4. (line 6713) ll request, using + and -: See 5.3. (line 3722) location, vertical, page, marking (mk): See 5.22. (line 8539) location, vertical, page, returning to marked (rt):See 5.22. (line 8539) logical not, limitation in expression: See 5.3. (line 3673) logical operators: See 5.3. (line 3665) long names: See 5.34. (line 10777) loops and conditionals: See 5.20. (line 7965) lq glyph, and lq string [man]: See 4.1.5. (line 1778) ls request, alternative to (pvs): See 5.18.1. (line 7588) lt request, using + and -: See 5.3. (line 3722) M unit: See 5.2. (line 3619) m unit: See 5.2. (line 3607) machine unit (u): See 5.2. (line 3564) macro arguments: See 5.5.1.1. (line 3948) macro arguments, and compatibility mode: See 5.32. (line 10458) macro arguments, and tabs: See 5.5.1.1. (line 3948) macro basics: See 3.1. (line 1100) macro directories: See 2.3. (line 915) macro files, searching: See 2.3. (line 920) macro name register (\$0): See 5.21.2. (line 8490) macro names, starting with [ or ], and refer: See 5.4. (line 3787) macro packages <1>: See 4. (line 1415) macro packages: See 1.4. (line 448) macro packages, structuring the source code: See 5.5.1. (line 3880) macro, appending (am): See 5.21. (line 8344) macro, arguments (\$): See 5.21.2. (line 8441) macro, creating alias (als): See 5.19. (line 7915) macro, end-of-input (em): See 5.24.6. (line 9309) macro, removing (rm): See 5.19. (line 7910) macro, removing alias (rm): See 5.19. (line 7950) macro, renaming (rn): See 5.19. (line 7907) macros: See 5.5.2. (line 4031) macros for manual pages [man]: See 4.1.2. (line 1523) macros, recursive: See 5.20.3. (line 8183) macros, searching: See 2.3. (line 915) macros, shared name space with strings and diversions:See 5.19. (line 7772) macros, tutorial for users: See 3. (line 1092) macros, writing: See 5.21. (line 8228) magnification of a font (fzoom): See 5.17.1. (line 6416) major quotes: See 3.2.5. (line 1313) major version number register (.x): See 5.6.5. (line 4593) man macros: See 4.1.2. (line 1523) man macros, bold face: See 4.1.3. (line 1659) man macros, custom headers and footers: See 4.1.7. (line 1804) man macros, default indentation: See 4.1.4. (line 1704) man macros, empty space before a paragraph: See 4.1.4. (line 1713) man macros, hanging indentation: See 4.1.2. (line 1616) man macros, how to set fonts: See 4.1.3. (line 1651) man macros, italic fonts: See 4.1.3. (line 1698) man macros, line breaks with vertical space: See 4.1.2. (line 1638) man macros, line breaks without vertical space:See 4.1.2. (line 1642) man macros, moving left margin: See 4.1.2. (line 1624) man macros, resetting default indentation: See 4.1.2. (line 1645) man macros, tab stops: See 4.1.4. (line 1708) man macros, Ultrix-specific: See 4.1.7. (line 1822) man pages: See 4.1. (line 1432) manipulating filling and adjusting: See 5.7. (line 4638) manipulating hyphenation: See 5.8. (line 4903) manipulating spacing: See 5.9. (line 5174) manmacros, BSD compatibility: See 4.1.4. (line 1724) manual pages: See 4.1. (line 1432) margin for hyphenation (hym): See 5.8. (line 5108) margin glyph (mc): See 5.31. (line 10286) margin, bottom: See 5.15. (line 6149) margin, left (po): See 5.13. (line 5894) margin, top: See 5.15. (line 6149) mark, high-water, register (.h): See 5.25. (line 9482) marking vertical page location (mk): See 5.22. (line 8539) MathML: See 7.8.2. (line 11412) maximum values of Roman numerals: See 5.6.4. (line 4485) mdoc macros: See 4.2. (line 1923) me macro package: See 4.4. (line 3350) measurement unit: See 5.2. (line 3564) measurements: See 5.2. (line 3564) measurements, specifying safely: See 5.2.1. (line 3645) minimum values of Roman numerals: See 5.6.4. (line 4485) minor version number register (.y): See 5.6.5. (line 4597) minutes, current time (minutes): See 5.6.5. (line 4539) mm macro package: See 4.5. (line 3356) mode for constant glyph space (cs): See 5.17.7. (line 7272) mode, compatibility: See 5.34. (line 10774) mode, compatibility, and parameters: See 5.32. (line 10458) mode, copy: See 5.21.1. (line 8400) mode, copy-in: See 5.21.1. (line 8400) mode, copy-in, and \!: See 5.25. (line 9560) mode, copy-in, and \? <1>: See 5.25. (line 9560) mode, copy-in, and \?: See 5.20.1. (line 8019) mode, copy-in, and \a: See 5.10.1. (line 5507) mode, copy-in, and \E: See 5.11. (line 5656) mode, copy-in, and \t: See 5.10. (line 5321) mode, copy-in, and \V: See 5.29. (line 10169) mode, copy-in, and cf request: See 5.29. (line 9959) mode, copy-in, and device request: See 5.30. (line 10188) mode, copy-in, and ig request: See 5.5.3.1. (line 4208) mode, copy-in, and length request: See 5.19. (line 7895) mode, copy-in, and macro arguments: See 5.21.2. (line 8441) mode, copy-in, and output request: See 5.25. (line 9592) mode, copy-in, and tm request: See 5.33. (line 10507) mode, copy-in, and tm1 request: See 5.33. (line 10507) mode, copy-in, and tmc request: See 5.33. (line 10507) mode, copy-in, and trf request: See 5.29. (line 9959) mode, copy-in, and write request: See 5.29. (line 10130) mode, copy-in, and writec request: See 5.29. (line 10130) mode, copy-in, and writem request: See 5.29. (line 10143) mode, fill <1>: See 5.33.1. (line 10667) mode, fill <2>: See 5.7. (line 4795) mode, fill: See 5.1.5. (line 3479) mode, fill (fi): See 5.7. (line 4663) mode, fill, and \c: See 5.14. (line 6114) mode, line-tabs: See 5.10. (line 5459) mode, no-fill (nf): See 5.7. (line 4673) mode, no-fill, and \c: See 5.14. (line 6104) mode, no-space (ns): See 5.9. (line 5301) mode, nroff: See 5.12. (line 5840) mode, safer <1>: See 5.29. (line 9941) mode, safer <2>: See 5.6.5. (line 4526) mode, safer <3>: See 2.3. (line 930) mode, safer: See 2.1. (line 747) mode, troff: See 5.12. (line 5840) mode, unsafe <1>: See 5.29. (line 9941) mode, unsafe <2>: See 5.6.5. (line 4526) mode, unsafe <3>: See 2.3. (line 930) mode, unsafe: See 2.1. (line 823) modifying requests: See 5.5.1. (line 3928) mom macro package: See 4.6. (line 3362) month of the year register (mo): See 5.6.5. (line 4553) motion operators: See 5.3. (line 3712) motion, horizontal (\h): See 5.22. (line 8640) motion, vertical (\v): See 5.22. (line 8615) motions, page: See 5.22. (line 8534) mounting font (fp): See 5.17.3. (line 6569) ms macros: See 4.3. (line 1929) ms macros, accent marks: See 4.3.6.5. (line 3060) ms macros, body text: See 4.3.5. (line 2341) ms macros, cover page: See 4.3.4. (line 2246) ms macros, creating table of contents: See 4.3.6.4. (line 2983) ms macros, differences from AT&T: See 4.3.7. (line 3190) ms macros, displays: See 4.3.5.7. (line 2724) ms macros, document control registers: See 4.3.3. (line 2003) ms macros, equations: See 4.3.5.8. (line 2820) ms macros, figures: See 4.3.5.8. (line 2820) ms macros, footers: See 4.3.6.1. (line 2912) ms macros, footnotes: See 4.3.5.10. (line 2874) ms macros, general structure: See 4.3.2. (line 1951) ms macros, headers: See 4.3.6.1. (line 2912) ms macros, headings: See 4.3.5.2. (line 2404) ms macros, highlighting: See 4.3.5.3. (line 2470) ms macros, keeps: See 4.3.5.7. (line 2724) ms macros, lists: See 4.3.5.4. (line 2538) ms macros, margins: See 4.3.6.2. (line 2956) ms macros, multiple columns: See 4.3.6.3. (line 2962) ms macros, naming conventions: See 4.3.8. (line 3321) ms macros, nested lists: See 4.3.5.4. (line 2663) ms macros, page layout: See 4.3.6. (line 2902) ms macros, paragraph handling: See 4.3.5.1. (line 2347) ms macros, references: See 4.3.5.8. (line 2820) ms macros, special characters: See 4.3.6.5. (line 3060) ms macros, strings: See 4.3.6.5. (line 3060) ms macros, tables: See 4.3.5.8. (line 2820) multi-file documents: See 5.33. (line 10487) multi-line strings: See 5.19. (line 7741) multi-page table, example markup [ms]: See 4.3.5.9. (line 2855) multiple columns [ms]: See 4.3.6.3. (line 2962) n unit: See 5.2. (line 3612) name space, common, of macros, diversions, and strings:See 5.19. (line 7772) name, background color, register (.M): See 5.28. (line 9903) name, drawing color, register (.m): See 5.28. (line 9873) name, fill color, register (.M): See 5.28. (line 9903) named character (\C): See 5.17.4. (line 6823) names, long: See 5.34. (line 10777) naming conventions, ms macros: See 4.3.8. (line 3321) ne request, and the .trunc register: See 5.24.1. (line 9181) ne request, comparison with sv: See 5.16. (line 6280) negating register values: See 5.6.1. (line 4301) nested assignments: See 5.6.2. (line 4351) nested diversions: See 5.25. (line 9475) nested lists [ms]: See 4.3.5.4. (line 2663) new page (bp) <1>: See 5.16. (line 6235) new page (bp): See 3.1. (line 1187) newline character <1>: See 5.5.3. (line 4106) newline character: See 5.4. (line 3749) newline character, and translations: See 5.11. (line 5748) newline character, in strings, escaping: See 5.19. (line 7741) newline, final, stripping in diversions: See 5.19. (line 7842) next file, processing (nx): See 5.29. (line 9993) next free font position register (.fp): See 5.17.3. (line 6586) nf request, causing implicit linebreak: See 5.7. (line 4638) nl register, and .d: See 5.25. (line 9475) nl register, difference to .h: See 5.25. (line 9495) nm request, using + and -: See 5.3. (line 3722) no-break control character ('): See 5.5.1. (line 3872) no-break control character, changing (c2): See 5.11. (line 5579) no-fill mode (nf): See 5.7. (line 4673) no-fill mode, and \c: See 5.14. (line 6104) no-space mode (ns): See 5.9. (line 5301) node, output: See 5.32. (line 10371) nr request, and warnings: See 5.33.1. (line 10705) nr request, using + and -: See 5.3. (line 3722) nroff mode: See 5.12. (line 5840) nroff, the program: See 1.2. (line 313) number of arguments register (.$): See 5.21.2. (line 8430) number of registers register (.R): See 5.6.5. (line 4522) number register, creating alias (aln): See 5.6.1. (line 4338) number register, removing (rr): See 5.6.1. (line 4330) number register, renaming (rnn): See 5.6.1. (line 4334) number registers, dumping (pnr): See 5.33. (line 10556) number, input line, setting (lf): See 5.33. (line 10487) number, page (pn): See 5.15. (line 6213) numbered glyph (\N) <1>: See 5.17.4. (line 6839) numbered glyph (\N): See 5.11. (line 5739) numbered list, example markup [ms]: See 4.3.5.4. (line 2576) numbers, and delimiters: See 5.5.3. (line 4102) numbers, line, printing (nm): See 5.31. (line 10220) numerals, Roman: See 5.6.4. (line 4457) numeric expression, valid: See 5.3. (line 3730) offset, page (po): See 5.13. (line 5894) open request, and safer mode: See 2.1. (line 747) opena request, and safer mode: See 2.1. (line 747) opening file (open): See 5.29. (line 10118) operator, scaling: See 5.3. (line 3702) operators, arithmetic: See 5.3. (line 3654) operators, as delimiters: See 5.5.3. (line 4104) operators, comparison: See 5.3. (line 3661) operators, extremum (>?, : See 5.6.5. (line 4631) output device name string register (.T): See 2.1. (line 812) output device usage number register (.T): See 2.1. (line 812) output devices <1>: See 7. (line 10963) output devices: See 1.6. (line 492) output encoding, ASCII: See 2.1. (line 783) output encoding, cp1047: See 2.1. (line 795) output encoding, EBCDIC: See 2.1. (line 795) output encoding, latin-1 (ISO 8859-1): See 2.1. (line 787) output encoding, utf-8: See 2.1. (line 791) output glyphs, and input characters,compatibility with AT&T troff:See 5.34. (line 10857) output line number register (ln): See 5.6.5. (line 4587) output line, continuation (\c): See 5.14. (line 6079) output line, horizontal position, register (.k):See 5.22. (line 8750) output node: See 5.32. (line 10371) output request, and \!: See 5.25. (line 9592) output request, and copy-in mode: See 5.25. (line 9592) output, flush (fl): See 5.33. (line 10566) output, gtroff: See 8.1. (line 11435) output, intermediate: See 8.1. (line 11445) output, suppressing (\O): See 5.27. (line 9756) output, transparent (\!, \?): See 5.25. (line 9547) output, transparent (cf, trf): See 5.29. (line 9959) output, transparent, incompatibilities with AT&T troff:See 5.34. (line 10878) output, troff: See 8.1. (line 11445) overlapping characters: See 5.17.4. (line 6904) overstriking glyphs (\o): See 5.22. (line 8754) P unit: See 5.2. (line 3592) p unit: See 5.2. (line 3588) packages, macros: See 4. (line 1415) padding character, for fields (fc): See 5.10.2. (line 5541) page break, conditional (ne): See 5.16. (line 6259) page control: See 5.16. (line 6231) page ejecting register (.pe): See 5.24.1. (line 9193) page footers: See 5.24.1. (line 9079) page headers: See 5.24.1. (line 9079) page layout: See 5.15. (line 6135) page layout [ms]: See 4.3.6. (line 2902) page length (pl): See 5.15. (line 6142) page length register (.p): See 5.15. (line 6146) page location traps: See 5.24.1. (line 9047) page location, vertical, marking (mk): See 5.22. (line 8539) page location, vertical, returning to marked (rt):See 5.22. (line 8539) page motions: See 5.22. (line 8534) page number (pn): See 5.15. (line 6213) page number character (%): See 5.15. (line 6164) page number character, changing (pc): See 5.15. (line 6222) page number register (%): See 5.16. (line 6253) page offset (po): See 5.13. (line 5894) page orientation, landscape: See 2.5. (line 988) page, new (bp): See 5.16. (line 6235) paper formats: See 3.2.9. (line 1370) paper size: See 2.5. (line 988) paragraphs: See 3.2.1. (line 1240) parameters: See 5.21.2. (line 8426) parameters, and compatibility mode: See 5.32. (line 10458) parentheses: See 5.3. (line 3706) path, for font files: See 2.4. (line 959) path, for tmac files: See 2.3. (line 920) patterns for hyphenation (hpf): See 5.8. (line 5013) PDF, embedding: See 7.4.2. (line 11163) pi request, and groff: See 5.29. (line 10074) pi request, and safer mode: See 2.1. (line 747) pic, the program: See 6.3. (line 10919) pica unit (P): See 5.2. (line 3592) pile, glyph (\b): See 5.23. (line 9014) pl request, using + and -: See 5.3. (line 3722) planting a trap: See 5.24. (line 9041) platform-specific directory: See 2.3. (line 935) pn request, using + and -: See 5.3. (line 3722) PNG image generation from PostScript: See 8.2.1. (line 12198) po request, using + and -: See 5.3. (line 3722) point size registers (.s, .ps): See 5.18.1. (line 7471) point size registers, last-requested (.psr, .sr):See 5.18.2. (line 7641) point sizes, changing (ps, \s): See 5.18.1. (line 7463) point sizes, fractional <1>: See 5.34. (line 10847) point sizes, fractional: See 5.18.2. (line 7604) point unit (p): See 5.2. (line 3588) polygon, drawing (\D'p ...'): See 5.23. (line 8937) polygon, solid, drawing (\D'P ...'): See 5.23. (line 8946) position of lowest text line (.h): See 5.25. (line 9482) position, absolute, operator (|): See 5.3. (line 3717) position, horizontal input line, saving (\k): See 5.22. (line 8741) position, horizontal, in input line, register (hp):See 5.22. (line 8747) position, horizontal, in output line, register (.k):See 5.22. (line 8750) position, vertical, current (nl): See 5.16. (line 6293) position, vertical, in diversion, register (.d):See 5.25. (line 9475) positions, font: See 5.17.3. (line 6562) post-vertical line spacing: See 5.18.1. (line 7573) post-vertical line spacing register (.pvs): See 5.18.1. (line 7588) post-vertical line spacing, changing (pvs): See 5.18.1. (line 7588) postprocessor access: See 5.30. (line 10176) postprocessors: See 1.6. (line 492) PostScript fonts: See 5.17.2. (line 6449) PostScript, bounding box: See 5.31. (line 10355) PostScript, embedding: See 7.3.2. (line 11095) PostScript, PNG image generation: See 8.2.1. (line 12198) preconv, invoking: See 6.9.1. (line 10960) preconv, the program: See 6.9. (line 10957) prefix, for commands: See 2.2. (line 868) preprocessor, calling convention: See 4.1.6. (line 1784) preprocessors <1>: See 6. (line 10901) preprocessors: See 1.5. (line 459) previous font (ft, \f[], \fP): See 5.17.1. (line 6365) previous line length (.n): See 5.26. (line 9749) print current page register (.P): See 2.1. (line 704) printing backslash (\\, \e, \E, \[rs]) <1>: See 5.34. (line 10878) printing backslash (\\, \e, \E, \[rs]): See 5.5.3. (line 4111) printing line numbers (nm): See 5.31. (line 10220) printing to stderr (tm, tm1, tmc): See 5.33. (line 10504) printing, zero-width (\z, \Z): See 5.22. (line 8758) process ID of gtroff register ($$): See 5.6.5. (line 4604) processing next file (nx): See 5.29. (line 9993) properties of characters (cflags): See 5.17.4. (line 6876) properties of glyphs (cflags): See 5.17.4. (line 6876) ps request, and constant glyph space mode: See 5.17.7. (line 7272) ps request, incompatibilities with AT&T troff: See 5.34. (line 10847) ps request, using + and -: See 5.3. (line 3722) ps request, with fractional type sizes: See 5.18.2. (line 7604) pso request, and safer mode: See 2.1. (line 747) pvs request, using + and -: See 5.3. (line 3722) quotes, major: See 3.2.5. (line 1313) quotes, trailing: See 5.19. (line 7734) radicalex glyph, and cflags: See 5.17.4. (line 6904) ragged-left: See 5.7. (line 4697) ragged-right: See 5.7. (line 4693) rc request, and glyph definitions: See 5.17.4. (line 6966) read-only register, changing format: See 5.6.4. (line 4494) reading from standard input (rd): See 5.29. (line 9998) recursive macros: See 5.20.3. (line 8183) refer, and macro names starting with [ or ]: See 5.4. (line 3787) refer, the program: See 6.7. (line 10945) reference, gtroff: See 5. (line 3369) references [ms]: See 4.3.5.8. (line 2820) register, creating alias (aln): See 5.6.1. (line 4338) register, format (\g): See 5.6.4. (line 4502) register, removing (rr): See 5.6.1. (line 4330) register, renaming (rnn): See 5.6.1. (line 4334) registers: See 5.6. (line 4217) registers specific to grohtml: See 7.8.2. (line 11392) registers, built-in: See 5.6.5. (line 4510) registers, interpolating (\n): See 5.6.2. (line 4346) registers, number of, register (.R): See 5.6.5. (line 4522) registers, setting (nr, \R): See 5.6.1. (line 4226) removing alias, for diversion (rm): See 5.19. (line 7950) removing alias, for macro (rm): See 5.19. (line 7950) removing alias, for string (rm): See 5.19. (line 7950) removing diversion (rm): See 5.19. (line 7910) removing glyph definition (rchar, rfschar): See 5.17.4. (line 7023) removing macro (rm): See 5.19. (line 7910) removing number register (rr): See 5.6.1. (line 4330) removing request (rm): See 5.19. (line 7910) removing string (rm): See 5.19. (line 7910) renaming diversion (rn): See 5.19. (line 7907) renaming macro (rn): See 5.19. (line 7907) renaming number register (rnn): See 5.6.1. (line 4334) renaming request (rn): See 5.19. (line 7907) renaming string (rn): See 5.19. (line 7907) request arguments: See 5.5.1.1. (line 3948) request arguments, and compatibility mode: See 5.32. (line 10458) request, removing (rm): See 5.19. (line 7910) request, renaming (rn): See 5.19. (line 7907) request, undefined: See 5.5.3.1. (line 4142) requests: See 5.5.1. (line 3872) requests for drawing: See 5.23. (line 8781) requests for input and output: See 5.29. (line 9914) requests, modifying: See 5.5.1. (line 3928) resolution, device: See 8.2.1. (line 12256) resolution, horizontal: See 8.2.1. (line 12194) resolution, horizontal, register (.H): See 5.6.5. (line 4519) resolution, vertical: See 8.2.1. (line 12305) resolution, vertical, register (.V): See 5.6.5. (line 4531) returning to marked vertical page location (rt):See 5.22. (line 8539) revision number register (.Y): See 5.6.5. (line 4601) rf, the program: See 1.2. (line 297) right-justifying (rj): See 5.7. (line 4893) rj request, causing implicit linebreak: See 5.7. (line 4638) rn glyph, and cflags: See 5.17.4. (line 6904) roff, the program: See 1.2. (line 308) roman glyph, correction after italic glyph (\/):See 5.17.8. (line 7358) roman glyph, correction before italic glyph (\,):See 5.17.8. (line 7370) Roman numerals: See 5.6.4. (line 4457) Roman numerals, maximum and minimum: See 5.6.4. (line 4485) rq glyph, and rq string [man]: See 4.1.5. (line 1778) rq glyph, at end of sentence <1>: See 5.17.4. (line 6914) rq glyph, at end of sentence: See 5.1.3. (line 3434) rt request, using + and -: See 5.3. (line 3722) ru glyph, and cflags: See 5.17.4. (line 6904) RUNOFF, the program: See 1.2. (line 297) s unit <1>: See 5.18.2. (line 7604) s unit: See 5.2. (line 3597) safer mode <1>: See 5.29. (line 9941) safer mode <2>: See 5.6.5. (line 4526) safer mode <3>: See 2.3. (line 930) safer mode: See 2.1. (line 747) saving horizontal input line position (\k): See 5.22. (line 8741) scaling indicator: See 5.2. (line 3564) scaling operator: See 5.3. (line 3702) searching fonts: See 2.4. (line 951) searching macro files: See 2.3. (line 920) searching macros: See 2.3. (line 915) seconds, current time (seconds): See 5.6.5. (line 4534) sentence space: See 5.1.3. (line 3427) sentence space size register (.sss): See 5.7. (line 4790) sentences: See 5.1.3. (line 3421) setting diversion trap (dt): See 5.24.2. (line 9229) setting end-of-input trap (em): See 5.24.6. (line 9309) setting input line number (lf): See 5.33. (line 10487) setting input line trap (it): See 5.24.3. (line 9244) setting registers (nr, \R): See 5.6.1. (line 4226) shading filled objects (\D'f ...'): See 5.23. (line 8920) shc request, and translations: See 5.11. (line 5752) site-specific directory <1>: See 2.4. (line 974) site-specific directory: See 2.3. (line 935) size of sentence space register (.sss): See 5.7. (line 4790) size of type: See 5.18. (line 7436) size of word space register (.ss): See 5.7. (line 4790) size, optical, of a font: See 5.17.1. (line 6416) size, paper: See 2.5. (line 988) sizes: See 5.18. (line 7436) sizes, fractional <1>: See 5.34. (line 10847) sizes, fractional: See 5.18.2. (line 7604) skew, of last glyph (.csk): See 5.26. (line 9734) slant, font, changing (\S): See 5.17.7. (line 7190) soelim, the program: See 6.8. (line 10951) soft hyphen character, setting (shc): See 5.8. (line 5138) soft hyphen glyph (hy): See 5.8. (line 5138) solid circle, drawing (\D'C ...'): See 5.23. (line 8893) solid ellipse, drawing (\D'E ...'): See 5.23. (line 8903) solid polygon, drawing (\D'P ...'): See 5.23. (line 8946) sp request, and no-space mode: See 5.9. (line 5301) sp request, and traps: See 5.9. (line 5225) sp request, causing implicit linebreak: See 5.7. (line 4638) space between sentences: See 5.1.3. (line 3427) space between sentences register (.sss): See 5.7. (line 4790) space between words register (.ss): See 5.7. (line 4790) space character: See 5.5.3. (line 4106) space character, zero width (\&) <1>: See 5.23. (line 8807) space character, zero width (\&) <2>: See 5.17.8. (line 7325) space character, zero width (\&): See 5.5.1. (line 3915) space characters, in expressions: See 5.3. (line 3733) space, discardable, horizontal: See 5.7. (line 4821) space, discarded, in traps: See 5.9. (line 5225) space, horizontal (\h): See 5.22. (line 8640) space, horizontal, unformatting: See 5.19. (line 7842) space, unbreakable: See 5.22. (line 8651) space, vertical, unit (v): See 5.2. (line 3615) space, width of a digit (\0): See 5.22. (line 8675) spaces with ds: See 5.19. (line 7734) spaces, in a macro argument: See 5.5.1.1. (line 3952) spaces, leading and trailing: See 5.1.1. (line 3394) spacing: See 3.1. (line 1179) spacing, manipulating: See 5.9. (line 5174) spacing, vertical: See 5.18. (line 7436) special characters <1>: See 7.1. (line 10966) special characters: See 5.11. (line 5739) special characters [ms]: See 4.3.6.5. (line 3060) special fonts <1>: See 8.2.2. (line 12341) special fonts <2>: See 5.17.6. (line 7119) special fonts: See 5.17.4. (line 6648) special fonts, emboldening: See 5.17.7. (line 7261) special request, and font translations: See 5.17.1. (line 6399) special request, and glyph search order: See 5.17.4. (line 6648) spline, drawing (\D'~ ...'): See 5.23. (line 8915) springing a trap: See 5.24. (line 9041) sqrtex glyph, and cflags: See 5.17.4. (line 6904) stacking glyphs (\b): See 5.23. (line 9014) standard input, reading from (rd): See 5.29. (line 9998) stderr, printing to (tm, tm1, tmc): See 5.33. (line 10504) stops, tabulator: See 5.1.4. (line 3446) string arguments: See 5.19. (line 7693) string comparison: See 5.20.1. (line 8010) string expansion (\*): See 5.19. (line 7693) string interpolation (\*): See 5.19. (line 7693) string, appending (as): See 5.19. (line 7862) string, creating alias (als): See 5.19. (line 7915) string, length of (length): See 5.19. (line 7895) string, removing (rm): See 5.19. (line 7910) string, removing alias (rm): See 5.19. (line 7950) string, renaming (rn): See 5.19. (line 7907) strings: See 5.19. (line 7680) strings [ms]: See 4.3.6.5. (line 3060) strings specific to grohtml: See 7.8.2. (line 11392) strings, multi-line: See 5.19. (line 7741) strings, shared name space with macros and diversions:See 5.19. (line 7772) stripping final newline in diversions: See 5.19. (line 7842) structuring source code of documents or macro packages:See 5.5.1. (line 3880) sty request, and changing fonts: See 5.17.1. (line 6353) sty request, and font positions: See 5.17.3. (line 6617) sty request, and font translations: See 5.17.1. (line 6399) styles, font: See 5.17.2. (line 6444) substring (substring): See 5.19. (line 7879) suppressing output (\O): See 5.27. (line 9756) sv request, and no-space mode: See 5.16. (line 6289) switching environments (ev): See 5.26. (line 9676) sy request, and safer mode: See 2.1. (line 747) symbol: See 5.17.4. (line 6648) symbol table, dumping (pm): See 5.33. (line 10545) symbol, defining (char): See 5.17.4. (line 6966) symbols, using: See 5.17.4. (line 6640) system() return value register (systat): See 5.29. (line 10113) tab character <1>: See 5.5.3. (line 4106) tab character: See 5.1.4. (line 3446) tab character, and translations: See 5.11. (line 5748) tab character, non-interpreted (\t): See 5.10. (line 5321) tab repetition character (tc): See 5.10. (line 5450) tab settings register (.tabs): See 5.10. (line 5437) tab stops: See 5.1.4. (line 3446) tab stops [man]: See 4.1.4. (line 1708) tab stops, for TTY output devices: See 5.10. (line 5435) tab, line-tabs mode: See 5.10. (line 5459) table of contents <1>: See 5.10.1. (line 5519) table of contents: See 3.2.7. (line 1350) table of contents, creating [ms]: See 4.3.6.4. (line 2983) tables [ms]: See 4.3.5.8. (line 2820) tabs, and fields: See 5.10. (line 5317) tabs, and macro arguments: See 5.5.1.1. (line 3948) tabs, before comments: See 5.5.3.1. (line 4138) tbl, the program: See 6.2. (line 10913) Teletype: See 7.2.1. (line 11023) terminal control sequences: See 7.2.1. (line 11023) terminal, conditional output for: See 5.20.1. (line 7976) text line, position of lowest (.h): See 5.25. (line 9482) text, gtroff processing: See 5.1. (line 3375) text, justifying: See 5.7. (line 4638) text, justifying (rj): See 5.7. (line 4893) thickness of lines (\D't ...'): See 5.23. (line 8987) three-part title (tl): See 5.15. (line 6164) ti request, causing implicit linebreak: See 5.7. (line 4638) ti request, using + and -: See 5.3. (line 3722) time, current: See 5.29. (line 10090) time, current, hours (hours): See 5.6.5. (line 4543) time, current, minutes (minutes): See 5.6.5. (line 4539) time, current, seconds (seconds): See 5.6.5. (line 4534) title line (tl): See 5.15. (line 6164) title line length register (.lt): See 5.15. (line 6196) title line, length (lt): See 5.15. (line 6196) title page, example markup: See 4.3.4. (line 2307) titles: See 5.15. (line 6160) tkf request, and font styles: See 5.17.2. (line 6499) tkf request, and font translations: See 5.17.1. (line 6399) tkf request, with fractional type sizes: See 5.18.2. (line 7604) tl request, and mc: See 5.31. (line 10315) tm request, and copy-in mode: See 5.33. (line 10507) tm1 request, and copy-in mode: See 5.33. (line 10507) tmac, directory: See 2.3. (line 920) tmac, path: See 2.3. (line 920) tmc request, and copy-in mode: See 5.33. (line 10507) TMPDIR, environment variable: See 2.2. (line 898) token, input: See 5.32. (line 10371) top margin: See 5.15. (line 6149) top-level diversion: See 5.25. (line 9416) top-level diversion, and \!: See 5.25. (line 9584) top-level diversion, and \?: See 5.25. (line 9589) top-level diversion, and bp: See 5.16. (line 6250) tr request, and glyph definitions: See 5.17.4. (line 6966) tr request, and soft hyphen character: See 5.8. (line 5138) tr request, incompatibilities with AT&T troff: See 5.34. (line 10857) track kerning: See 5.17.8. (line 7331) track kerning, activating (tkf): See 5.17.8. (line 7338) trailing quotes: See 5.19. (line 7734) trailing spaces: See 5.1.1. (line 3394) translations of characters: See 5.11. (line 5579) transparent characters <1>: See 5.17.4. (line 6914) transparent characters: See 5.1.3. (line 3434) transparent output (\!, \?): See 5.25. (line 9547) transparent output (cf, trf): See 5.29. (line 9959) transparent output, incompatibilities with AT&T troff:See 5.34. (line 10878) trap, changing location (ch): See 5.24.1. (line 9160) trap, distance, register (.t): See 5.24.1. (line 9151) trap, diversion, setting (dt): See 5.24.2. (line 9229) trap, end-of-input, setting (em): See 5.24.6. (line 9309) trap, input line, setting (it): See 5.24.3. (line 9244) trap, planting: See 5.24. (line 9041) trap, springing: See 5.24. (line 9041) traps: See 5.24. (line 9036) traps, and discarded space: See 5.9. (line 5225) traps, and diversions: See 5.24.1. (line 9217) traps, blank line: See 5.24.4. (line 9272) traps, diversion: See 5.24.2. (line 9228) traps, dumping (ptr): See 5.33. (line 10560) traps, end-of-input: See 5.24.6. (line 9308) traps, input line: See 5.24.3. (line 9242) traps, input line, and interrupted lines (itc):See 5.24.3. (line 9261) traps, leading spaces: See 5.24.5. (line 9279) traps, page location: See 5.24.1. (line 9047) traps, sprung by bp request (.pe): See 5.24.1. (line 9193) trf request, and copy-in mode: See 5.29. (line 9959) trf request, and invalid characters: See 5.29. (line 9982) trf request, causing implicit linebreak: See 5.7. (line 4638) trin request, and asciify: See 5.25. (line 9608) troff mode: See 5.12. (line 5840) troff output: See 8.1. (line 11445) truncated vertical space register (.trunc): See 5.24.1. (line 9181) TTY, conditional output for: See 5.20.1. (line 7976) tutorial for macro users: See 3. (line 1092) type size: See 5.18. (line 7436) type size registers (.s, .ps): See 5.18.1. (line 7471) type sizes, changing (ps, \s): See 5.18.1. (line 7463) type sizes, fractional <1>: See 5.34. (line 10847) type sizes, fractional: See 5.18.2. (line 7604) u unit: See 5.2. (line 3564) uf request, and font styles: See 5.17.2. (line 6499) ul glyph, and cflags: See 5.17.4. (line 6904) ul request, and font translations: See 5.17.1. (line 6399) Ultrix-specific man macros: See 4.1.7. (line 1822) unary operators: See 5.3. (line 3667) unbreakable space: See 5.22. (line 8651) undefined identifiers: See 5.4. (line 3820) undefined request: See 5.5.3.1. (line 4142) underline font (uf): See 5.17.7. (line 7236) underlining (ul): See 5.17.7. (line 7210) underlining, continuous (cu): See 5.17.7. (line 7232) underscore glyph (\[ru]): See 5.23. (line 8803) unformatting diversions (asciify): See 5.25. (line 9608) unformatting horizontal space: See 5.19. (line 7842) Unicode <1>: See 5.17.4. (line 6839) Unicode: See 5.4. (line 3754) unit, c: See 5.2. (line 3585) unit, f: See 5.2. (line 3600) unit, f, and colors: See 5.28. (line 9838) unit, i: See 5.2. (line 3580) unit, M: See 5.2. (line 3619) unit, m: See 5.2. (line 3607) unit, n: See 5.2. (line 3612) unit, P: See 5.2. (line 3592) unit, p: See 5.2. (line 3588) unit, s <1>: See 5.18.2. (line 7604) unit, s: See 5.2. (line 3597) unit, u: See 5.2. (line 3564) unit, v: See 5.2. (line 3615) unit, z <1>: See 5.18.2. (line 7604) unit, z: See 5.2. (line 3597) units of measurement: See 5.2. (line 3564) units, default: See 5.2.1. (line 3626) unnamed fill colors (\D'F...'): See 5.23. (line 8997) unnamed glyphs: See 5.17.4. (line 6850) unnamed glyphs, accessing with \N: See 8.2.2. (line 12364) unsafe mode <1>: See 5.29. (line 9941) unsafe mode <2>: See 5.6.5. (line 4526) unsafe mode <3>: See 2.3. (line 930) unsafe mode: See 2.1. (line 823) user's macro tutorial: See 3. (line 1092) user's tutorial for macros: See 3. (line 1092) using symbols: See 5.17.4. (line 6640) utf-8, output encoding: See 2.1. (line 791) v unit: See 5.2. (line 3615) valid numeric expression: See 5.3. (line 3730) value, incrementing without changing the register:See 5.6.3. (line 4423) variables in environment: See 2.2. (line 860) version number, major, register (.x): See 5.6.5. (line 4593) version number, minor, register (.y): See 5.6.5. (line 4597) vertical line drawing (\L): See 5.23. (line 8826) vertical line spacing register (.v): See 5.18.1. (line 7539) vertical line spacing, changing (vs): See 5.18.1. (line 7539) vertical line spacing, effective value: See 5.18.1. (line 7557) vertical motion (\v): See 5.22. (line 8615) vertical page location, marking (mk): See 5.22. (line 8539) vertical page location, returning to marked (rt):See 5.22. (line 8539) vertical position in diversion register (.d): See 5.25. (line 9475) vertical position trap enable register (.vpt): See 5.24.1. (line 9059) vertical position traps, enabling (vpt): See 5.24.1. (line 9059) vertical position, current (nl): See 5.16. (line 6293) vertical resolution: See 8.2.1. (line 12305) vertical resolution register (.V): See 5.6.5. (line 4531) vertical space unit (v): See 5.2. (line 3615) vertical spacing: See 5.18. (line 7436) warnings <1>: See 5.33.1. (line 10650) warnings: See 5.33. (line 10631) warnings, level (warn): See 5.33. (line 10637) what is groff?: See 1.1. (line 261) while: See 5.20.3. (line 8149) while request, and font translations: See 5.17.1. (line 6399) while request, and the ! operator: See 5.3. (line 3667) while request, confusing with br: See 5.20.3. (line 8216) while request, operators to use with: See 5.20.1. (line 7968) whitespace characters: See 5.4. (line 3749) width escape (\w): See 5.22. (line 8690) width, of last glyph (.w): See 5.26. (line 9734) word space size register (.ss): See 5.7. (line 4790) write request, and copy-in mode: See 5.29. (line 10130) writec request, and copy-in mode: See 5.29. (line 10130) writem request, and copy-in mode: See 5.29. (line 10143) writing macros: See 5.21. (line 8228) writing to file (write, writec): See 5.29. (line 10130) year, current, register (year, yr): See 5.6.5. (line 4556) z unit <1>: See 5.18.2. (line 7604) z unit: See 5.2. (line 3597) zero width space character (\&) <1>: See 5.23. (line 8807) zero width space character (\&) <2>: See 5.17.8. (line 7325) zero width space character (\&): See 5.5.1. (line 3915) zero-width printing (\z, \Z): See 5.22. (line 8758) zoom factor of a font (fzoom): See 5.17.1. (line 6416) |, and page motion: See 5.3. (line 3717)  Local Variables: coding: iso-8859-1 End: