This manual is for GNU Hello (version 2.7, 22 March 2011), which prints a friendly greeting (and serves as an example GNU package).
|• Overview:||General purpose and information.|
|• Sample output:|| Sample output from |
|• Invoking hello:|| How to run |
|• Reporting bugs:||Sending bug reports and feature suggestions.|
|• GNU Free Documentation License:||Copying and sharing this documentation.|
|• Concept index:||Index of concepts.|
(http://www.gnu.org/software/hello/) produces a familiar,
friendly greeting. It allows nonprogrammers to use a classic computer
science tool which would otherwise be unavailable to them. Because it
is protected by the GNU General Public License, users are free (in
perpetuity) to share and change it.
Not to spoil the joke, but of course the practical purpose of GNU Hello is to serve as a minimal example of a GNU package. So, although most manuals don’t need to discuss the implementation of the programs they document, that is part of the goal here.
First, GNU Hello follows the GNU coding standards (see Preface in GNU Coding Standards) and GNU maintainer standards (see Preface in Information for GNU Maintainers). These are the basic documents which all GNU packages should adhere to.
The Hello package also implements recommended development practices not embodied in the standards, using other GNU packages and features:
srclist-updateare used, for purposes of example. See the ‘README-dev’ file in the distribution.
getopt_longfunction (see Getopt Long Options in GNU C Library) to parse options, thus supporting GNU-style long options such as ‘--help’.
help2man(see Overview in GNU
help2man) from the ‘--help’ output. This relieves the maintainers from the burden of updating separate man documentation, yet provides a reasonable overview for man devotees.
GNU Hello is implemented in C. The GNU Gettext distribution contains “hello world” examples in many other programming languages; see the Gettext home page at http://www.gnu.org/software/gettext/.
The top-level ‘Makefile.am’ in Hello also contains a few special targets for other projects to adapt as desired:
Make a diff from the previous release, assuming the current tarball is in the current tarball.
Verify that all source files using
_() are included for
translation in ‘po/POTFILES.in’, so translators will have all the
Sample procedure for updating the manual on the GNU web site, in this case http://www.gnu.org/software/hello/manual/.
GNU Hello was written by Mike Haertel, David MacKenzie, Jan Brittenson, Charles Hannum, Roland McGrath, Noah Friedman, Karl Eichwalder, Karl Berry, and The King.
Here are some examples of running GNU Hello.
This is the output of the command ‘hello’:
This is the output of the command ‘hello --traditional’:
This is the output of the command ‘hello --greeting=hi’:
The format for running the
hello program is:
hello option …
With no options,
hello prints the greeting ‘Hello,
hello supports the following options:
Output text instead of the default greeting.
Print an informative help message on standard output and exit successfully.
For the ‘--help’ output of GNU programs, it’s strongly encouraged to include a brief (one or two sentences) description of what the program does, as well as the synopsis of how to run the program. Any environment variables which affect execution should also be mentioned (Hello doesn’t have any).
Output ‘Hello, world!’, but possibly including box-drawing characters or other fancy stuff, especially in translated locales. (If you would like to volunteer to translate messages for GNU packages, please see http://translationproject.org.)
Output the traditional greeting message ‘hello, world’.
Print the version number and licensing information of Hello on standard output and then exit successfully.
If more than one of the greeting options (‘-g’, ‘-n’, ‘-t’, and their long-named equivalents) is specified, whichever comes last takes precedence.
To report bugs or suggest enhancements for GNU Hello, please send electronic mail to firstname.lastname@example.org.
For bug reports, please include enough information for the maintainers to reproduce the problem. Generally speaking, that means:
configureother than specifying installation directories.
When in doubt whether something is needed or not, include it. It’s better to include too much than to leave out something important.
Patches are welcome; if possible, please make them with ‘diff -c’ (see Overview in Comparing and Merging Files) and include ‘ChangeLog’ entries (see Change Log in The GNU Emacs Manual). Please follow the existing coding style.
Version 1.3, 3 November 2008
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A B C E F G H I J K M O P R S T U
|bug reporting:||Reporting bugs|
|checklist for bug reports:||Reporting bugs|
|environment variables, help for:||Invoking hello|
|GNU coding standards:||Overview|
|GNU maintainer standards:||Overview|
|patches, contributing:||Reporting bugs|
|‘README-dev’ source file:||Overview|
|reporting bugs:||Reporting bugs|
|sample output:||Sample output|
|standards, GNU coding:||Overview|
|standards, GNU maintainer:||Overview|
A B C E F G H I J K M O P R S T U