Git on Windows: How do you set up a mergetool?

Question

I've tried msysGit and Git on Cygwin. Both work just fine in and of themselves and both run gitk and git-gui perfectly.

Now how the heck do I configure a mergetool? (Vimdiff works on Cygwin, but preferrably I would like something a little more user-friendly for some of our more... Windows-loving coworkers.)

Thanks!

Answer 1

git mergetool is fully configurable so you can pretty much chose your favourite tool.

The full documentation is here: http://www.kernel.org/pub/software/scm/git/docs/git-mergetool.html

In brief, you can set a default mergetool by setting the user config variable merge.tool.

If the merge tool is one of the ones supported natively by it you just have to set mergetool.<tool>.path to the full path to the tool (replace <tool> by what you have configured merge.tool to be.

Otherwise, you can set mergetool.<tool>.cmd to a bit of shell to be eval'ed at runtime with the shell variables $BASE, $LOCAL, $REMOTE, $MERGED set to the appropriate files. You have to be a bit careful with the escaping whether you directly edit a config file or set the variable with the git config command.

Something like this should give the flavour of what you can do ('mymerge' is a fictional tool).

git config merge.tool mymerge
git config merge.mymerge.cmd 'mymerge.exe --base "$BASE" "$LOCAL" "$REMOTE" -o "$MERGED"'

Once you've setup your favourite merge tool, it's simply a matter of running git mergetool whenever you have conflicts to resolve.

The p4merge tool from Perforce is a pretty good standalone merge tool.

Answer 2

As already answered here (and here and here), mergetool is the command to configure this. For a nice graphical frontend I recommend kdiff3 (GPL).

Answer 3

To follow-up on Charles Bailey's answer, here's my git setup that's using p4merge (free cross-platform 3way merge tool); tested on msys Git (Windows) install:

git config --global merge.tool p4merge
git config --global mergetool.p4merge.cmd 'p4merge.exe \"$BASE\" \"$LOCAL\" \"$REMOTE\" \"$MERGED\"'

The changes (relative to Charles Bailey):

• added to global git config, i.e. valid for all git projects not just the current one
• the custom tool config value resides in "mergetool.[tool].cmd", not "merge.[tool].cmd" (silly me, spent an hour troubleshooting why git kept complaining about non-existing tool)
• added double quotes for all file names so that files with spaces can still be found by the merge tool (I tested this in msys Git from Powershell)
• note that by default Perforce will add its installation dir to PATH, thus no need to specify full path to p4merge in the command

Answer 4

I had to drop the extra quoting using msysGit on windows 7, not sure why.

git config --global merge.tool p4merge
git config --global mergetool.p4merge.cmd 'p4merge $BASE $LOCAL $REMOTE $MERGED'

Answer 5

If you're doing this through cygwin, you may need to use cygpath:

git config --global merge.tool p4merge
git config --global mergetool.p4merge.cmd 'p4merge `cygpath -w $BASE` `cygpath -w $LOCAL` `cygpath -w $REMOTE` `cygpath -w $MERGED`'