Configuring a diff-tool for Git on Windows

Question

Since git diff in powershell mostly results in a unreadable amount of whitespace or strange characters, I installed Perforce P4Merge, to handle merging and diff.

However, I can't make git diff open the p4merge application to view the diff in. So far my .gitconfig looks like this:

[diff]
    tool = p4diff

[difftool "p4diff"]
    external = 'C:/PROGRA~1/Perforce/p4merge.exe "$LOCAL" "$REMOTE"'
    prompt = false

[merge]
    keepBackup = false
    tool = p4merge

[mergetool "p4merge"]
    cmd = "$BASE" "$LOCAL" "$REMOTE" "$MERGED"
    path = 'C:/PROGRA~1/Perforce/p4merge.exe'
    prompt = false
    keepBackup = false
    keepTemporaries = false
    trustExitCode = false

The paths are correct. But alas, git still attempts to present the diff in Powershell, when using git diff.

So what's the trick to make this work?

Answer 1

In your command prompt, try: git config --global diff.tool p4diff

That worked for me, using a config file set up as you had described:

[diff]  
    tool = p4merge  
[difftool "p4diff"]  
    external = '"C:/Program Files/Perforce/p4merge.exe" "$LOCAL" "$REMOTE"'

Running git difftool opened p4merge as expected.

Ref: How do I view 'git diff' output with a visual diff program?

Answer 2

I'm on WIndows 7 using MSysGit v1.8.4.

For me, the only solution was to add p4merge to the system path variable (reboot needed afterwards). Having done this, i conf'd it like this:

git config --global diff.tool p4merge
git config --global difftool.p4merge.cmd 'p4merge.exe $LOCAL $REMOTE'
git config --global difftool.prompt false

git config --global merge.tool p4merge
git config --global mergetool.p4merge.cmd 'p4merge.exe $BASE $LOCAL $REMOTE $MERGED'
git config --global mergetool.prompt false
git config --global mergetool.trustExitCode false
git config --global mergetool.keepBackup false

I recommend you stick to "git config" instead of editing the conf manually because hyphens etc sometimes are different between these methods.