title: How can I visualize per-character differences in a unified diff file?
body: <p>Say I get a patch created with <code>git format-patch</code>. The file is basically a unified diff with some metadata. If I open the file in Vim, I can see which lines have been modified, but I cannot see which <em>characters</em> in the changed lines differ. Does anyone know a way (in Vim, or some other free software that runs on Ubuntu) to visualize per-character differences?</p>
  
  <p>A counter example where per-character diff is visualized is when executing <code>vimdiff a b</code>.</p>
  
  <p><strong>update Fri Nov 12 22:36:23 UTC 2010</strong></p>
  
  <p><a href="https://stackoverflow.com/questions/242646/use-vimdiff-with-a-diff-file/244766#244766">diffpatch is helpful</a> for the scenario where you're working with a single file.</p>
  
  <p><strong>update Thu Jun 16 17:56:10 UTC 2016</strong></p>
  
  <p>Check out <a href="https://github.com/blog/2188-git-2-9-has-been-released" rel="noreferrer">diff-highlight in git 2.9</a>. This script does <em>exactly</em> what I was originally seeking.</p>