Cdiff
=====

.. image:: https://travis-ci.org/ymattw/cdiff.png?branch=master
:target: https://travis-ci.org/ymattw/cdiff
:alt: Build status

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``.

.. image:: https://raw.github.com/ymattw/cdiff/gh-pages/img/default.png
:alt: default
:align: center

.. image:: https://raw.github.com/ymattw/cdiff/gh-pages/img/side-by-side.png
:alt: side by side
:align: center
:width: 900 px

Installation
------------

Install with pip
~~~~~~~~~~~~~~~~

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

.. _PyPI: http://pypi.python.org/pypi/cdiff

.. code-block:: bash

pip install --upgrade cdiff

Install with setup.py
~~~~~~~~~~~~~~~~~~~~~

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

.. code-block:: bash

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

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``.

.. _`cdiff.py`: https://raw.github.com/ymattw/cdiff/master/cdiff.py

.. code-block:: bash

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

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

.. code-block:: bash

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:

.. code-block:: bash

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

Pipe in a diff:

.. code-block:: bash

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:

.. code-block:: bash

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.

.. _`travis build`: https://travis-ci.org/ymattw/cdiff/pull_requests

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`_.

.. _coderev: https://github.com/ymattw/coderev
.. _colordiff: https://github.com/daveewart/colordiff

.. vim:set ft=rst et sw=4 sts=4 tw=79: