Git External Merge & Diff Tools: Commands, Examples & Guide

Original chapter reference: Chapter 53: External merge and difftools. The command options and documentation recipes below are fully transcribed from Git Notes for Professionals.

Section 53.1: Setting up KDiff3 as merge tool

The following should be added to your global .gitconfig file

Source example · PDF page 176

[merge]
    tool = kdiff3
[mergetool "kdiff3"]
    path = D:/Program Files (x86)/KDiff3/kdiff3.exe
    keepBackup = false
    keepbackup = false
    trustExitCode = false

Remember to set the path property to point to the directory where you have installed KDiff3

Section 53.2: Setting up KDiff3 as diff tool

Source example · PDF page 176

[diff]
    tool = kdiff3
    guitool = kdiff3
[difftool "kdiff3"]
    path = D:/Program Files (x86)/KDiff3/kdiff3.exe
    cmd = \"D:/Program Files (x86)/KDiff3/kdiff3.exe\" \"$LOCAL\" \"$REMOTE\"

Section 53.3: Setting up an IntelliJ IDE as merge tool (Windows)

Source example · PDF page 176

[merge]
    tool = intellij
[mergetool "intellij"]
    cmd = cmd \"/C D:\\workspace\\tools\\symlink\\idea\\bin\\idea.bat merge $(cd $(dirname
"$LOCAL") && pwd)/$(basename "$LOCAL") $(cd $(dirname "$REMOTE") && pwd)/$(basename "$REMOTE") $(cd
$(dirname "$BASE") && pwd)/$(basename "$BASE") $(cd $(dirname "$MERGED") && pwd)/$(basename
"$MERGED")\"
    keepBackup = false
    keepbackup = false
    trustExitCode = true

The one gotcha here is that this cmd property does not accept any weird characters in the path. If your IDE's install location has weird characters in it (e.g. it's installed in Program Files (x86), you'll have to create a symlink

Section 53.4: Setting up an IntelliJ IDE as diff tool (Windows)

Source example · PDF page 176

[diff]
    tool = intellij
    guitool = intellij
[difftool "intellij"]
    path = D:/Program Files (x86)/JetBrains/IntelliJ IDEA 2016.2/bin/idea.bat
    cmd = cmd \"/C D:\\workspace\\tools\\symlink\\idea\\bin\\idea.bat diff $(cd $(dirname "$LOCAL")
&& pwd)/$(basename "$LOCAL") $(cd $(dirname "$REMOTE") && pwd)/$(basename "$REMOTE")\"

Section 53.5: Setting up Beyond Compare

You can set the path to bcomp.exe

Source example · PDF page 177

git config --global difftool.bc3.path 'c:\Program Files (x86)\Beyond Compare 3\bcomp.exe'

and configure bc3 as default

Source example · PDF page 177

git config --global diff.tool bc3