title: Compare all files of a folder pairwise
body: <p>Input:</p>
  <p>z2042 <br />
  z0138 <br />
  z0189 <br />
  z2294</p>
  <p>Hello,</p>
  <p>I want to compare all files in a folder with each other to see, if they are different.
  So like: z2042 with z0138, z0138 with z0189, z0189 with z2042 and so on...</p>
  <p>I know how to compare all files with a single file:</p>
  <p><code>for i in ./z*; do diff -q &quot;$i&quot; z2294; done</code></p>
  <p>But i dont know how to compare all files with all.
  I tried it with another for loop for with the Variable &quot;x&quot; instead of z2294, but it didnt work :/</p>
  <p>Thx for help</p>