View colored, incremental diff in workspace or from stdin with side by side and auto pager support (Was "cdiff")
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ymattw Support perforce workspaces
Probing perforce workspaces is tricky, so far 'p4 dirs .' is the best.

NOTE: this commit is rewritten to remove sensitive information in the
test input data (tests/perforce/in.diff).
Latest commit 574f42b Jul 11, 2018



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Term based tool to view colored, incremental diff in a version controlled workspace (supports Git, Mercurial, Perforce and Svn so far) or from stdin, with side by side (similar to diff -y) and auto pager support. Requires python (>= 2.5.0) and less.


side by side


Install with pip

Ydiff is already listed on PyPI, you can install with pip if you have the tool.

pip install --upgrade ydiff

Install with

You can also run the from the source if you don't have pip.

git clone
cd ydiff
./ install

Install with Homebrew

You can also install with Homebrew on Mac. (Thanks to @josa42, @bfontaine, @hivehand and @nijikon for contributing to the Homebrew Formula).

brew install ydiff

Download directly

Just save to whatever directory which is in your $PATH, for example, $HOME/bin is in my $PATH, so I save the script there and name as ydiff.

curl -ksSL > ~/bin/ydiff
chmod +x ~/bin/ydiff


Type ydiff -h to show usage:

$ ydiff -h
Usage: ydiff [options] [file|dir ...]

View colored, incremental diff in a workspace or from stdin, with side by side
and auto pager support

  --version            show program's version number and exit
  -h, --help           show this help message and exit
  -s, --side-by-side   enable side-by-side mode
  -w N, --width=N      set text width for side-by-side mode, 0 for auto
                       detection, default is 80
  -l, --log            show log with changes from revision control
  -c M, --color=M      colorize mode 'auto' (default), 'always', or 'never'
  -t N, --tab-width=N  convert tab characters to this many spaces (default: 8)
  --wrap               wrap long lines in side-by-side view

    Option parser will stop on first unknown option and pass them down to
    underneath revision control. Environment variable YDIFF_OPTIONS may be
    used to specify default options that will be placed at the beginning
    of the argument list.

Read diff from local modification in a Git/Mercurial/Svn workspace (output from e.g. git diff, svn diff):

cd proj-workspace
ydiff                         # view colored incremental diff
ydiff -s                      # view side by side, use default text width 80
ydiff -s -w 90                # use text width 90 other than default 80
ydiff -s -w 0                 # auto set text width based on terminal size
ydiff -s -w 0 --wrap          # same as before, but also wrap long lines
ydiff -s file1 dir2           # view modification of given files/dirs only
ydiff -s -w90 --wrap -- -U10  # pass '-U10' to underneath revision diff tool
ydiff -s -w90 --wrap -U10     # '--' is optional as it's unknown to ydiff
ydiff -s --cached             # show git staged diff (git diff --cached)
ydiff -s -r1234               # show svn diff to revision 1234

Read log with changes in a Git/Mercurial/Svn workspace (output from e.g. git log -p, svn log --diff), note --diff option is new in svn 1.7.0:

cd proj-workspace
ydiff -l                    # read log along with changes
ydiff -ls                   # equivalent to ydiff -l -s, view side by side
ydiff -ls -w90 --wrap       # set text width 90 and enable wrapping as well
ydiff -ls file1 dir2        # see log with changes of given files/dirs only

Environment variable YDIFF_OPTIONS may be used to specify default options that will be placed at the beginning of the argument list, for example:

export YDIFF_OPTIONS='-s -w0 --wrap'
ydiff foo                   # equivalent to "ydiff -s -w0 --wrap foo"

If you feel more comfortable with a command such as git ydiff to trigger the ydiff command, you may symlink the executable to one named git-ydiff as follows:

ydiff_dir=$(dirname $(which ydiff))
ln -s "${ydiff_dir}/ydiff" "${ydiff_dir}/git-ydiff"

Pipe in a diff:

git log -p -2 | ydiff       # view git log with changes of last 2 commits
git show 15bfa | ydiff -s   # view a given git commit, side by side
svn diff -r1234 | ydiff -s  # view svn diff comparing to given revision
diff -u file1 file2 | ydiff # view diff between two files (note the '-u')
diff -ur dir1 dir2 | ydiff  # view diff between two dirs

# View diff in a GitHub pull request, side by side
curl | ydiff -s

# View a patch file in unified or context format, the latter depends on
# command `filterdiff` from package `patchutils` which is available in
# major Linux distros and MacPorts.
ydiff -s < foo.patch

Redirect output to another patch file is safe:

svn diff -r PREV | ydiff -s > my.patch


Ydiff has following known issues:

  • Does not recognize normal diff, and depends on filterdiff (patchutils) to read context diff
  • Side by side mode has alignment problem for wide chars
  • Terminal might be in a mess on exception (type reset can fix it)

Pull requests are very welcome, please make sure your changes can pass unit tests and regression tests by run make test (required tool coverage can be installed with pip install coverage). Also watch out travis build after push, make sure it passes as well.

See also

I have another tool coderev which generates side-by-side diff pages for code review from two given files or directories, I found it's not easy to extend to support git so invented ydiff. Idea of ansi color markup is also from project colordiff.