README.rst 6.8KB

Ydiff
=====

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

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

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

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

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

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

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

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

.. code-block:: bash

pip install --upgrade ydiff

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/ydiff.git
cd ydiff
./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/ydiff.rb

.. code-block:: bash

brew install ydiff

Download directly
~~~~~~~~~~~~~~~~~

Just save `ydiff.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 ``ydiff``.

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

.. code-block:: bash

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

Usage
-----

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

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'
-t N, --tab-width=N convert tab characters to this many spaces (default: 8)
--wrap wrap long lines in side-by-side view

Note:
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``):

.. code-block:: bash

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:

.. code-block:: bash

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:

.. code-block:: bash

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:

.. code-block:: bash

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

Pipe in a diff:

.. code-block:: bash

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 https://github.com/ymattw/ydiff/pull/11.diff | 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:

.. code-block:: bash

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

Notes
-----

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.

.. _`travis build`: https://travis-ci.org/ymattw/ydiff/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 `ydiff`. Idea of ansi color markup is also from
project `colordiff`_.

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

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