Setup p4merge as a visual diff and merge tool for git

p4merge4git.md

Download and install p4merge

• Download the perforce visual tool suite from here: http://www.perforce.com/perforce/downloads/index.html
• Copy only the p4merge.app file into your /Applications/ directory

Setup p4merge as a visual mergetool

$ git config --global merge.tool p4mergetool
$ git config --global mergetool.p4mergetool.cmd \
"/Applications/p4merge.app/Contents/Resources/launchp4merge \$PWD/\$BASE \$PWD/\$REMOTE \$PWD/\$LOCAL \$PWD/\$MERGED"
$ git config --global mergetool.p4mergetool.trustExitCode false
$ git config --global mergetool.keepBackup false

Setup p4merge as a visual diff tool

$ git config --global diff.tool p4mergetool
$ git config --global difftool.p4mergetool.cmd \
"/Applications/p4merge.app/Contents/Resources/launchp4merge \$LOCAL \$REMOTE"

Using p4merge to resolve conflicts

When you run into a conflict when merging simply run:

$ git mergetool

• You will be prompted to run "p4mergetool", hit enter and the visual merge editor will launch.
• Using the merge tool you can resolve the conflict and then save the file.
• After you exit the merge tool take a look back at your terminal. You will be asked if the merge was successful, choose yes if all is well or no if you need to start over.
• This prompting is happening because the "trustExitCode" option is turned off. Personally I always like to be asked, but you can have git just trust the exit code from the merge tool.

if you want git to skip prompting for confirmation to open every single file do this:
git config --global --add difftool.prompt false

Thanks!

After I resolve a merge, I get /Applications/Xcode.app/Contents/Developer/usr/libexec/git-core/git-mergetool--lib: line 128: 8522 Segmentation fault: 11 /Applications/p4merge.app/Contents/Resources/launchp4merge $PWD/$BASE $PWD/$REMOTE $PWD/$LOCAL $PWD/$MERGED. How can I fix this?

merge config given at https://apple.stackexchange.com/a/346038/267749 worked instead for me.
P4Merge version -> Rev. P4Merge/MACOSX1015X86_64/2020.1/1966006
Git version -> git version 2.24.3 (Apple Git-128)

Most recent version of git already have included configuration for P4Merge. The only thing you need to do on a Mac is:

# setup p4merge as the default difftool
git config --global diff.tool p4merge

# setup p4merge as the default mergetool
git config --global merge.tool p4merge

# Define the path to P4merge launcher.
git config --global mergetool.p4merge.path /Applications/p4merge.app/Contents/Resources/launchp4merge

Note the p4merge instead of p4mergetool. This will setup P4Merge with the correct launch arguments. This was tested with:

• P4Merge/MACOSX1015X86_64/2020.3/2060285
• MacOS Catalina 10.15.7 (19H114)
• git version 2.30.0 (also tested with git version 2.24.1)

At the end, the only required configuration related to P4 you need in your .gitconfig (excluding your personal preferences) should be:

[diff]
  tool = p4merge
[merge]
  tool = p4merge
[mergetool "p4merge"]
  path = /Applications/p4merge.app/Contents/Resources/launchp4merge

Works perfectly for me, @louim, thanks 👍

Thank you @louim, works like a charm 👍

Does it prompts you for files when you run git diff-tool master..develop for example?
For me, it does and shouldn't be like that.

There is a window that asks about the paths, but there is also a confirmation dialog that asks if it is OK for an Applescript to be run, and when you approve it to run the script (which you only have to do once), then the path window disappears and the merge opens as expected. I installed via homebrew.

Still works perfectly in 2023. macOS Ventura