Document the ability to use this script as the default git diff external program about icdiff

[OliverJAsh]

I've got this working with git diff, but not git add --patch. Any ideas how to make this work ubiquitously?

[rockwelln]

After reading your post, I wanted to make a try with Mercurial.

As explain here: http://mercurial.selenic.com/wiki/ExtdiffExtension
It's sufficient to add the following in the file ~/.hgrc

[extensions]
hgext.extdiff=

[extdiff]
cmd.diff=icdiff

Seems working just fine :-).

[k4nar]

I don't really like changing the default diff tool, so I would like to use an alias instead, like git icdiff.
So far I got GIT_EXTERNAL_DIFF='sh -c "icdiff \"$2\" \"$5\""' git diff working, but I don't know how to turn it into a git alias.

[desyncr]

I got it configured as my difftool (git difftool --help) with the following configuration in ~/.gitconfig:

[diff]
    tool = icdiff

[difftool "icdiff"]
    cmd = icdiff $LOCAL $REMOTE

It preserves the default behavior of git diff but aliasing git difftool to gd works just fine 👍

[jomo]

@desyncr you might want to quote that: cmd = icdiff "$LOCAL" "$REMOTE"

[blueyed]

@desyncr
That does not use a pager, does it? Setting pager.difftool = true does that, but then it fails miserable with the vimdiff difftool.

I've also tried passing it the --no-bold option (I am using the Solarized colorscheme, where this is recommended), but that also fails:

[difftool "icdiff"]
cmd = git-icdiff --no-bold "$LOCAL" "$REMOTE"

+ git difftool --no-prompt --extcmd icdiff --no-bold+  /tmp/VbQI5y_pyenv.vim autoload/pyenv.vim
less --no-init --quit-if-one-screen
fatal: invalid diff option/value: --no-bold

Using it via `git-icdiff` does not display the colors, but Escape codes (this is caused by `LESS_IS_MORE=1`), and fails after quitting `less` before everything has been read:
Exception ignored in: <_io.TextIOWrapper name='<stdout>' mode='w' encoding='UTF-8'>
BrokenPipeError: [Errno 32] Broken pipe
Exception ignored in: <_io.TextIOWrapper name='<stdout>' mode='w' encoding='UTF-8'>
BrokenPipeError: [Errno 32] Broken pipe

Instead of LESS_IS_MORE, less' -F or --quit-if-one-screen option should be used - or just do not set/change it altogether, using the user's config (via Git's core.pager and the $LESS environment variable).

I think I'll be sticking to vimdiff for Git, but having icdiff in general is nice!

[desyncr]

@k4nar:
To create any git <anything> command you just need to create an executable inside /usr/lib/git-core/ directory (or similar in your system):

$ cat /usr/lib/git-core/git-icdiff
#!/bin/bash
git difftool

Then I can execute git icdiff and git difftool is executed. In order for this to work with icdiff you need to configure your git difftool appropriately:

$ cat ~/.gitconfig
[diff]
    tool = icdiff
[difftool]
    prompt = false
[difftool "icdiff"]
    cmd = icdiff $LOCAL $REMOTE

Remember to chmod u+x your script. If you don't know where to put your script execute locate git-config and the path where git-config file is located is the one you're looking for.

Obviously more advanced things can be implemented.

[desyncr]

Regarding the original approach it can be reduced to:

$ cat /usr/local/bin/ext-diff
#!/bin/bash
icdiff $2 $5

With the following git configuration:

[diff]
    external = ext-diff
[core]
    pager = 

Hope that helps.

[k4nar]

@desyncr : Thanks, I'll try that !

[JoseAlban]

As of today, after installing it via brew, I aliased the wrapper coming with icdiff version 1.7.2:
alias gdi="$(brew --prefix icdiff)/bin/git-icdiff $GIT_DIFF_OPTIONS"
and it works fine, compared against the analogous:
git diff $GIT_DIFF_OPTIONS

[JoseAlban]

To get the file labels correctly, plus other personally cool features, I have now in my .gitconfig:

[pager]
    difftool = true
[diff]
    tool = icdiff
[difftool "icdiff"]
    cmd = icdiff --head=5000 --highlight --line-numbers -L \"$BASE\" -L \"$REMOTE\" \"$LOCAL\" \"$REMOTE\"

And I use it like: git difftool

[jez]

@JoseAlban What do the first four lines do? Can they be used independently of the last two lines?

Edit: Should have read the documentation first, it's all explained very clearly. Here are the relevant lines from git-config(1):

diff.tool
       Controls which diff tool is used by git-difftool(1). This variable overrides
       the value configured in merge.tool. The list below shows the valid built-in
       values. Any other value is treated as a custom diff tool and requires that a
       corresponding difftool.<tool>.cmd variable is defined.

...

difftool.<tool>.cmd
       Specify the command to invoke the specified diff tool. The specified command is
       evaluated in shell with the following variables available: LOCAL is set to the
       name of the temporary file containing the contents of the diff pre-image and
       REMOTE is set to the name of the temporary file containing the contents of the
       diff post-image.

...

pager.<cmd>
       If the value is boolean, turns on or off pagination of the output of a
       particular Git subcommand when writing to a tty. Otherwise, turns on pagination
       for the subcommand using the pager specified by the value of pager.<cmd>. If
       --paginate or --no-pager is specified on the command line, it takes precedence
       over this option. To disable pagination for all commands, set core.pager or
       GIT_PAGER to cat.

For the record, I also went ahead and set difftool.prompt = false, like others have mentioned:

difftool.prompt
       Prompt before each invocation of the diff tool.

[JoseAlban]

@jez exactly! I just couldn't tie it together nicely with git show :( but it has by itself an inline diff (surprisingly), which is what I use (although I wish I could do icdiff still):

git show --word-diff

[jeffkaufman]

git-icdiff is now part of the default install (and has been for a while)