Nice stuff to do with diff commands:
====== Compare output of 2 commands ======
===== Basic =====
<code bash>diff <(command 1) <(command 2)</code>
===== Side by side =====
<code bash>diff -y <(command 1) <(command 2)</code>
You can control the width of the columns
<code bash>diff -y --width= XXX<(command 1) <(command 2)</code>
Where XXX is the number of columns