cdiff 1.0

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

Cdiff

Term based tool to view colored, incremental diff in a Git/Mercurial/Svn workspace or from stdin, with side by side and auto pager support. Requires python (>= 2.5.0) and less.

Installation

Install with pip

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

pip install --upgrade cdiff

Install with setup.py

You can also run the setup.py from the source if you don’t have pip.

git clone https://github.com/ymattw/cdiff.git
cd cdiff
./setup.py 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 cdiff

Download directly

Just save cdiff.py 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 cdiff.

curl -ksSL https://raw.github.com/ymattw/cdiff/master/cdiff.py > ~/bin/cdiff
chmod +x ~/bin/cdiff

Usage

Type cdiff -h to show usage:

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

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

Options:
  --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'

  Note:
    Option parser will stop on first unknown option and pass them down to
    underneath revision control. Environment variable CDIFF_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
cdiff                       # view colored incremental diff
cdiff -s                    # view side by side, use default text width 80
cdiff -s -w 90              # use text width 90 other than default 80
cdiff -s -w 0               # auto set text width based on terminal size
cdiff -s file1 dir2         # view modification of given files/dirs only
cdiff -s -w90 -- -U10       # pass '-U10' to underneath revision diff tool
cdiff -s -w90 -U10          # '--' is optional as it's unknown to cdiff
cdiff -s --cached           # show git staged diff (git diff --cached)
cdiff -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
cdiff -l                    # read log along with changes
cdiff -ls                   # equivalent to cdiff -l -s, view side by side
cdiff -ls -w90              # set text width 90 as well
cdiff -ls file1 dir2        # see log with changes of given files/dirs only

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

export CDIFF_OPTIONS='-s -w0'
cdiff foo                   # equivalent to "cdiff -s -w0 foo"

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

cdiff_dir=$(dirname $(which cdiff))
ln -s "${cdiff_dir}/cdiff" "${cdiff_dir}/git-cdiff"

Pipe in a diff:

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

# View diff in a GitHub pull request, side by side
curl https://github.com/ymattw/cdiff/pull/11.diff | cdiff -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.
#
cdiff -s < foo.patch

Redirect output to another patch file is safe:

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

Notes

Cdiff 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 cdiff. Idea of ansi color markup is also from project colordiff.

Change log

Version 1.0 (2016-12-31)

• Use environment variable CDIFF_OPTIONS to hold default options

Version 0.9.8 (2016-01-16)

• More robust parser to tolerate evil unified diff

Version 0.9.7 (2015-04-24)

• Fix unexpected side-by-side output for diff of diff

• Better color to work with solarized color scheme

Version 0.9.6 (2014-06-20)

• Fix TypeError exception in auto width logic

Version 0.9.5 (2014-06-19)

• Option --width 0 now fits terminal size automatically

• Enable smooth horizontal scrolling with less option --shift 1

Version 0.9.4 (2014-06-04)

• Respect the LESS environment variable

• Support python 3.4

• Fix curl options in document

Version 0.9.3 (2013-09-28)

• Moved screenshots to ‘gh-pages’ branch

• Handle all keyboard interrupts more completely

• Explicitly set default encoding to utf-8

• Fixed broken output diff when I/O with filterdiff in nonblocking mode

Version 0.9.2 (2013-06-21)

• Enahanced option parser now pass unknown option to underneath revision control, user can use cdiff --cached, cdiff -U5 directly

Version 0.9.1 (2013-05-20)

• Use --no-ext-diff to disable GIT_EXTERNAL_DIFF and diff.external which might break cdiff output

Version 0.9 (2013-03-23)

• Supports reading context diff via filterdiff (patchutils)

• Fixed a diff parser bug which misread git commit message as common line

• Lots of code refactor

Version 0.8 (2013-03-13)

• Parser is now robust enough to handle dangling headers and short patch

• PEP8 (with minor own flavors) and other code lint

• Change ‘Development Status’ to stable

Version 0.7.1 (2013-02-25)

• Handle ‘Binary files … differ’

• Document update for known issues

Version 0.7 (2013-02-23)

• Support reading diff or log for given files/dirs in workspace

• Support diff generated from diff -ru dir1 dir2

• Usage change: reading a patch and comparing two files need stdin redirect

Version 0.6 (2013-02-20)

• A few performance tuning and code clean up

• Add unit test cases with coverage 70%

• Show merge history in svn log

Version 0.5.1 (2013-02-19)

• Fixed incorrect yield on diff missing eof

• Fixed a bug in diff format probe

• Handle keyboard interrupt and large diffs in non-color mode

• Code clean up

Version 0.5 (2013-02-18)

• Support read output from svn diff --log and hg log -p

• Streamline reading large patch set

• New --log (-l) option to read revision control diff log (thanks to Steven Myint)

Version 0.4 (2013-02-16)

• New option -c WHEN (–color WHEN) to support auto test

• Auto regression test now on Travis

Version 0.3 (2013-02-07)

• Support compare two files (wrapper of diff)

Version 0.2 (2013-02-06)

• Move cdiff.py to top dir for better meta info management

Version 0.1 (2013-02-05)

• New –version option

• setup.py now read version from source code

Version 0.0.4 (2013-02-04)

• Add CHANGES for history track and better versioning

Version 0.0.3 (2013-02-04)

• Publish on PyPI, supports read patch from file, pipe and diff output from revision tools (thanks to Steven Myint)