cdiff

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

Install with Homebrew

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

.. _`@josa42`: https://github.com/josa42
.. _`@bfontaine`: https://github.com/bfontaine
.. _`@hivehand`: https://github.com/hivehand
.. _`@nijikon`: https://github.com/nijikon
.. _`Formula`: https://github.com/Homebrew/homebrew-core/blob/master/Formula/cdiff.rb

.. code-block:: bash

    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``.

.. _`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. 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``):

.. 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

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

.. code-block:: bash

    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:

.. code-block:: bash

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

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:

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`_)

.. _Steven Myint: https://github.com/myint

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