NOTE: The functionality provided by git-diffall has been contributed to Git
itself and can be accessed through the "git difftool --dir-diff" command
in Git versions v1.7.11 and newer.

## Overview
The git-diffall script provides a directory based diff mechanism
for git.

To determine what diff viewer is used, the script requires either
the 'diff.tool' or 'merge.tool' configuration option to be set.

This script is compatible with most common forms used to specify a
range of revisions to diff:

  1. git diffall: shows diff between working tree and staged changes
  2. git diffall --cached [<commit>]: shows diff between staged
     changes and HEAD (or other named commit)
  3. git diffall <commit>: shows diff between working tree and named
     commit
  4. git diffall <commit> <commit>: show diff between two named commits
  5. git diffall <commit>..<commit>: same as above
  6. git diffall <commit>...<commit>: show the changes on the branch
     containing and up to the second, starting at a common ancestor
     of both <commit>

Note: all forms take an optional path limiter [-- <path>*]

The '--extcmd=<command>' option allows the user to specify a custom
command for viewing diffs.  When given, configured defaults are
ignored and the script runs $command $LOCAL $REMOTE.  Additionally,
$BASE is set in the environment.

## Installation
Copy the `git-diffall` script to the directory where your `git` is installed.

`$ cd <directory with git-diffall>`
`$ cp git-diffall $(git --exec-path)`

## Setup
The difftool and mergetool selected for use with `git-diffall` must be one that has a mergetool plugin in your `git` installation.  The plugin is a simple script that populates the command-line arguments of the difftool/mergetool using the correct values from `git`.  Plugins exist for a variety of tools already and can be found in `$(git --exec-path)/mergetools`.  If your favorite tool is missing, you can add it by copying an existing plugin and modifying for your tool.

The config commands follow this pattern:

`$ git config --global diff.tool <one of the tools listed in $(git --exec-path)/mergetools>`
`$ git config --global merge.tool <one of the tools listed in $(git --exec-path)/mergetools>`

For example:

`$ git config --global diff.tool kdiff3`
`$ git config --global merge.tool kdiff3`


## Other Notes
This script is based on an example provided by Thomas Rast on the
Git list [1]:

[1] https://thread.gmane.org/gmane.comp.version-control.git/124807

"git cola diff" [2] provides a graphical frontend for full-tree diffs similar
in spirit to git-diffall.

[2] https://github.com/git-cola/git-cola