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.