gdiffmk - mark differences between groff/nroff/troff files
gdiffmk compares two groff(1), nroff(1), or troff(1)
documents, file1 and file2, and creates an output which is
file2 with added “margin character” (.mc) commands that
indicate the differences.
[-d deletemark] [-D
[-B] [-M mark1 mark2]] [-x
diffcmd] [--] file1
If the output filename is present, the output is written
there. If it is - or absent the output is written to the standard
If the file1 or file2 argument is - the
standard input is read for that input. Clearly both cannot be -.
Note that the output is not necessarily compatible with all macro
packages and all preprocessors. See section “Bugs” below.
The output is not necessarily compatible with all macro packages and all
preprocessors. A workaround that is often successful against preprocessor
problems is to run gdiffmk on the output of all the preprocessors
instead of the input source.
- Use the addmark for source lines not in file1 but present in
file2. Default: +.
- By default, the deleted texts marked by the -D option end with an
added troff break command, .br, to ensure that the deletions are
marked properly. This is the only way to guarantee that deletions and
small changes get flagged. This option directs the program not to insert
these breaks; it makes no sense to use it without -D.
- Use the changemark for changed source lines. Default:
- Use the deletemark for deleted source lines. Default:
- Show the deleted portions from changed and deleted text. Default
delimiting marks: [[ ... ]].
- -Mmark1 mark2
- Change the delimiting marks for the -D option. It makes no sense to
use this option without -D.
- Use the diffcmd command to perform the comparison of file1
and file2. In particular, diffcmd should accept the GNU
diff -Dname option. Default: diff(1).
- All the following arguments are treated as file names, even if they begin
- Print a usage message on standard error output and exit.
- Print version information on the standard output and exit.
gdiffmk relies on the -Dname option of GNU
diff(1) to make a merged “#ifdef” output format. It
hasn't been tested whether other versions of diff(1) do support this
option. See also the -xdiffcmd option.