Ydiff

.. image:: https://github.com/ymattw/ydiff/actions/workflows/test.yml/badge.svg :alt: Tests status :target: https://github.com/ymattw/ydiff/actions

Ydiff is a terminal-based tool to view colored, incremental diffs in a version-controlled workspace or from stdin, in side-by-side (similar to diff -y) or unified mode, and auto-paged. It only requires Python >= 3.3 without external dependencies and less as a pager.

The diffs in side-by-side mode appear below. See also the screenshots_ of the unified mode.

.. _screenshots: https://github.com/ymattw/ydiff/tree/26857b8/img

Theme "default" on a dark terminal background:

.. image:: https://raw.githubusercontent.com/ymattw/ydiff/26857b8/img/darkbg-side-by-side-default.png :alt: side by side, theme 'default' on a dark background :align: center :height: 300 px

Theme "default" on a light terminal background:

.. image:: https://raw.githubusercontent.com/ymattw/ydiff/26857b8/img/lightbg-side-by-side-default.png :alt: side by side, theme 'default' on a light background :align: center :height: 300 px

Theme "dark" on a dark terminal background:

.. image:: https://raw.githubusercontent.com/ymattw/ydiff/26857b8/img/darkbg-side-by-side-dark.png :alt: side by side, theme 'dark' on a dark background :align: center :height: 300 px

Theme "light" on a light terminal background:

.. image:: https://raw.githubusercontent.com/ymattw/ydiff/26857b8/img/lightbg-side-by-side-light.png :alt: side by side, theme 'light' on a light background :align: center :height: 300 px

Installation

Ydiff only depends on Python built-in libraries, so you can just download the source and run without worrying about any installation. Git tagged_ revisions will be packaged and uploaded to PyPI_ timely, however, packages hosted elsewhere are not (please note they are not managed by the author @ymattw_).

.. _tagged: https://github.com/ymattw/ydiff/tags .. _PyPI: http://pypi.python.org/pypi/ydiff .. _@ymattw: https://github.com/ymattw

To run from source directly, just save ydiff.py_ as ydiff to whatever directory which is in your $PATH, for example, $HOME/bin:

.. _ydiff.py: https://raw.github.com/ymattw/ydiff/master/ydiff.py

.. code-block:: bash

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

To install from PyPI_:

.. code-block:: bash

pip install --upgrade ydiff

To install with Homebrew (Formula_) on macOS:

.. _Formula: https://github.com/Homebrew/homebrew-core/blob/master/Formula/y/ydiff.rb

.. code-block:: bash

brew install ydiff

To install on Fedora:

.. code-block:: bash

dnf install ydiff

To install on FreeBSD:

.. code-block:: bash

pkg install 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 (default True; DEPRECATED)
  -u, --unified         show diff in unified mode (disables side-by-side mode)
  -w N, --width=N       set text width for side-by-side mode, 0 (default) for
                        auto detection and fallback to 80 when not possible
  -l, --log             show log with changes from revision control
  -c WHEN, --color=WHEN
                        colorize mode 'auto' (default), 'always', or 'never'
  -t N, --tab-width=N   convert tab chars to this many spaces (default: 8)
  --wrap                wrap long lines in side-by-side mode (default True;
                        DEPRECATED)
  --nowrap, --no-wrap   do not wrap long lines in side-by-side mode
  -p PAGER, --pager=PAGER
                        pager application to feed output to, default is 'less'
  -o OPT, --pager-options=OPT
                        options to supply to pager application
  --theme=THEME         option to pick a color theme (one of dark, default,
                        light)

  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/Perforce/Svn workspace (output from e.g. git diff, svn diff):

.. code-block:: bash

cd proj-workspace
ydiff                       # view colored side by side diff, auto set text
                            # width based on terminal size
ydiff -u                    # view colored incremental diff in unified mode
ydiff -w 90                 # use text width 90, wrap long lines
ydiff --no-wrap             # auto set text width but do not wrap long lines
ydiff file1 dir2            # view modification of given files/dirs only
ydiff -w90 -U10             # pass '-U10' to underneath revision diff tool
ydiff --cached              # show git staged diff (git diff --cached)
ydiff -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, side by side
ydiff -lu                   # equivalent to ydiff -l -u, unified mode
ydiff -l -w90 --no-wrap     # set text width 90 and disable wrapping
ydiff -l file1 dir2         # see log with changes of given files/dirs only

Utilize a specific pager application:

.. code-block:: bash

ydiff -p more                   # use "more" as a pager
ydiff -p cat                    # when neither less nor more is avilable
ydiff -o "-FRSX --shift 2"      # customized option (pager defaults to less)

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      # view a given git commit, side by side
svn diff -r1234 | ydiff     # 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

# View a patch file in colored unified format.
ydiff -u < foo.patch

Redirect output to another patch file is safe even without -u:

.. code-block:: bash

svn diff -r PREV | ydiff > my.patch

Customized themes

You can define your own themes in ~/.config/ydiff/themes.ini. Check out the built-in themes_ for examples.

.. _built-in themes: https://github.com/search?q=repo%3Aymattw%2Fydiff+%2F_BUILTIN_THEMES+%3D%2F&type=code

The section names are theme names. Undeclared theme keys will inherit values from the same-named built-in theme or from the "default" theme otherwise.

Notes

1. Ydiff only supports diffs in Unified Format_. Diffs in other format may be converted to Unified Format via tool filterdiff (usually offered by package patchutils.)

   .. _Unified Format: https://en.wikipedia.org/wiki/Diff#Unified_format

2. 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='-w100' ydiff foo # equivalent to "ydiff -w100 foo"

3. If you feel more comfortable with a command such as git d to trigger the ydiff command, you may symlink the executable to one named git-d, or configure an alias:

   .. code-block:: bash

   Create a symlink git-d -> ydiff

   D=$(dirname $(which ydiff)); ln -s ydiff $D/git-d

   Or configure an alias

   git config --global alias.d '!ydiff'

Known issues

• Wide characters may cause alignment problem in side-by-side mode.
• Terminal might be in a mess on exception (type reset can fix it).

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