A colored diff that also colors inside changed lines

usage: ccdiff [options] file1 [file2]
       ccdiff --help | --man | --info
	file1 or file2 can be - (but not both)

All command-line tools that show the difference between two files fall short in showing minor changes visuably useful. This tool tries to give the look and feel of diff --color or colordiff, but extending the display of colored output from red for deleted lines and green for added lines to red for deleted characters and green for added characters within the changed lines.

The tool has options to choose your own favorite color combinations, as long as they are supported by Term::ANSIColor.

If you want no colors but indicators below the removed/added characters in the output, which is very useful if you want to email the output, the option --no-color adds those indicators. With the --fancy option you will get Unicode characters.

Change the first line of ccdiff to start your favorite perl interpreter and then move the file to a folder in your $PATH.

• diff

• diff --color

• colordiff

• git

  This however requires a long command:

$ git -c color.diff.new='bold reverse green' \
         -c color.diff.old='bold reverse red'   \
         diff --no-index -U0 --no-color \
              --word-diff=color --word-diff-regex=. \
             <file1> <file2>

• vimdiff

Please never use the xdiff command (if available at all), because it is included in many distributions and/or packages and they all work different or not at all. Some at not intended to be invoked from the command line.

The list is in increasing clarity of the tool being able to show minor changes in lines visually outstanding:

• mgdiff (C, X11)

• diffuse (Python)

• bcompare (C, X11, not freeware/opensource)

• kompare (C, X11, KDE)

• xxdiff (C, X11)

• meld (Python)

• kdiff3 (C, X11, Qt)

• tkdiff (Tcl/Tk)

This tool will run on recent perl distributions that have Algorithm::Diff installed. The modules Term::ANSIColor and Getopt::Long that are also used are part of the perl CORE distribution since at least version 5.6.0.

 suse#   zypper in perl-Algorithm-Diff

 centos# yum install -y perl-Algorithm-Diff

 other#  cpan Algorithm::Diff

You can use ccdiff to show diffs in git. It may work like this:

$ git config --global diff.tool ccdiff
$ git config --global difftool.prompt false
$ git config --global difftool.ccdiff.cmd 'ccdiff --utf-8 -u -r $LOCAL $REMOTE'
$ git difftool SHA~..SHA
$ cat >~/bin/git-ccdiff <<EOF
#!/bin/sh

commit=$1
shift
git difftool $commit~1..$commit $@
EOF
$ chmod 755 ~/bin/git-ccdiff
$ git ccdiff SHA

There is no provision yet for showing zero-width unicode "characters", like U+200b (ZERO WIDTH SPACE), U+200c (ZERO WITDH NON_JOINER), U+200D (ZERO WIDTH JOINER), and U+feff (ZERO WIDTH NO-BREAK SPACE) will not show (yet) in normal output and might cause displacement of other indicators.

There is no provision (yet) for coping with double-width characters.

Large datasets may consume all available memory, causing the diff to fail.

The Artistic License 2.0

Copyright (c) 2018-2018 H.Merijn Brand