Are you using [Git](http://git.or.cz/) in Ubuntu and want to use an external visual diff viewer? It's easy! I will be using [Meld](http://meld.sourceforge.net/) for this example but most visual diff tools should be similar. If you don't already have Meld, then install it: <code class="terminal">sudo apt-get install meld</code> Ok. Now let's begin by breaking it. Enter this into a terminal: <code class="terminal">git config --global diff.external meld</code> Then navigate to a Git tracked directory and enter this (with an actual filename): <code class="terminal">git diff filename</code> Meld will open but it will complain about bad parameters. The problem is that Git sends its external diff viewer seven parameters when Meld only needs two of them; two filenames of files to compare. One way to fix it is to write a script to format the parameters before sending them to Meld. Let's do that. Create a new python script in your home directory (or wherever, it doesn't matter) and call it _diff.py_. #!/usr/bin/python import sys import os os.system('meld "%s" "%s"' % (sys.argv[2], sys.argv[5])) Now we can set Git to perform it's diff on our new script (replacing the path with yours): <code class="terminal">git config --global diff.external /home/nathan/diff.py git diff filename</code> This time when we do a diff it will launch Meld with the right parameters and we will see our visual diff. 2009-06-03T23:07:29+10:00 38 true 2008-06-02T22:10:00+10:00 2009-06-03T23:08:24+10:00 how-to-meld-for-git-diffs-in-ubuntu-hardy