ildar-shaimordanov / colordiff

Wrapper for diff to colorize its output for better readability

colordiff

• colordiff
• Usage
  • colordiff options
  • Environment
• Requirements
• See Also
• License

colordiff is a pure shell script acting as a wrapper for diff. It supports a lot of diff outputs and makes them looking prettier highlighting similar to git diff.

The script analysizes the command line options, select proper colorizing scheme, invokes diff and applies sed with the selected scheme.

Usage

Use colordiff in the same way as well as diff:

colordiff [diff options] [colordiff options] file1 file2

Run the script with no options to learn how to use it -- not a long help page will be displayed.

The tool can be used as a standalone executable script or a shell function sourced from ~/.bashrc or aliased as follows:

# Let's check and use diff itself or git diff
if diff --help 2>/dev/null | grep -q color
then
	# diff 3.4+ allows coloring
	alias diff='diff --color=auto'
elif which git > /dev/null 2>&1
then
	# git is available
	alias diff='git diff --no-index'
fi

# If one of these scripts exists, overwrite the alias for better colorizing
if which ~/bin/colordiff.posix > /dev/null 2>&1
then
	# Let's check and use POSIX-compliant shell script
	alias diff=~/bin/colordiff.posix
elif which ~/bin/colordiff.bash > /dev/null 2>&1
then
	# Let's check and use full-featured Bash script
	alias diff=~/bin/colordiff.bash
elif which colordiff > /dev/null 2>&1
then
	# Let's check and use well-known script from www.colordiff.org
	alias diff=colordiff
fi

colordiff options

• --color[=WHEN], --colour[=WHEN] - the colorizing method; WHEN stands for never, auto and always (default value, if not specified explicitly).

Environment

• CDIFF_WHEN - the colorizing method has impact on all runs.
• CDIFF_COLORS - the colon-separated list of capabilities to colorize the separate parts of the diff output. Colors are defined in the terms of git-config and defaults to meta=40;1;37:frag=36:old=31:new=32:mod=34 (bold white for metainformation or headers, cyan for hunk headers or line numbers, red for deleted lines, green for added lines and blue for modified lines, respectively).

Requirements

The latest version of the script was developed and successfully tested in the following environment:

• cygwin 1.45, 3.1.7
• bash 4.2, 4.4
• busybox 1.33.0
• sed 4.2, 4.4

See Also

• grep(1) - for the --color/--colour options.
• git-config(1) - for the color.diff.<slot> parameters. colordiff uses the same terminology.
• Options to diff - including diff 3.4+ options https://www.gnu.org/software/diffutils/manual/html_node/diff-Options.html

There is another Perl script with the same functionality. It exists in two versions maintained by its authors:

• version 1.x: https://github.com/daveewart/colordiff
• version 2.x: https://github.com/kimmel/colordiff

License

MIT License