www.LinuxHowtos.org

gdiffmk

Section: User Commands (1)
Updated: 202-0-28
Index Return to Main Contents

Name

gdiffmk - mark differences between groff/nroff/troff files
.nr d-fallback 1
.nr d-fallback 1

Synopsis

[-a~ad-mark] [-c~chang-mark] [-d~delet-mark] [-x~dif-command] [-D [-B] [-M mark1 mark2]] [--] file1 file2 [outpu-file] --help --version

Description

gdiffmk compares two documents, file1 and file2, and writes another, derived from both, to the standard output stream (or outpu-file), adding margin character (mc) requests at places in the output where the input documents differ. gdiffmk does not interpret the source documents; it treats roff comments and nilpotent changes to formatting as meaningful. For example, it does not know that [rs]h[aq]3m[aq], [rs]h[aq](1~*~3m)[aq], and [rs]h[aq]3m+0[aq] all mean the same thing. If the file1 or file2 argument is [lq]-[rq], gdiffmk reads the standard input stream for that input. If the output operand is present, gdiffmk writes output to a file of that name. If it is [lq]-[rq] or absent, gdiffmk writes output to the standard output stream. [lq]-[rq] cannot be both an input and output operand.

Options

--help displays a usage message and --version shows version information; both exit afterward.

-a~ad-mark: Annotate material absent from file1 but present in file2 with ad-mark (default: [lq]+[rq]).
-B: Suppress br requests normally inserted by -D option. Use with caution; such requests are the only way to guarantee that deletions and small changes are marked.
-c~chang-mark: Annotate material differing between file1 and file2 with chang-mark (default: [lq]|[rq]).
-d~delet-mark: Annotate material present in file1 but absent from file2 with delet-mark (default: [lq]*[rq]).
-D: Mark changed and deleted material with surrounding delimiters.
-M~mark1 mark2: Use mark1 (default: [lq][[[rq]) and mark2 (default: [lq]]][rq]) as delimiters when using the -D option.
-x~dif-command: Use the dif-command program to perform the comparison of file1 and file2. dif-command (default: diff) must accept GNU -D extension option.
--: Treat all subsequent arguments as file names, even if they begin with [lq]-[rq].

Exit status

gdiffmk exits with status~0 if the input files are the same; 1 if they differ; 2 upon a usage error; 3 if the system's or commands do not support features gdiffmk requires; and 4 if the output argument is a duplicate of file1 or file2.

Caveats

The output is not necessarily compatible with all macro packages or preprocessors. A reliable workaround is to run gdiffmk on the output of the final preprocessor instead of the input source.

gdiffmk relies on the -D option of GNU diff to make a merged [lq]#ifdef[rq] output format. Busybox diff is known to not support it. Also see the -x~dif-command option.

Authors

gdiffmk was written by Mike Bianchi now retired. It is maintained by the groff developers.