title: subtraction in linux shell if
body: <p>In linux bash shell, how to subtract a variable from another in <code>if</code>? I've tried the following:</p>
  
  <pre><code>#!/bin/bash
  start=0
  end=1
  if [ end - start -eq 1 ]; then
      echo "right"
  fi
  </code></pre>
  
  <p>It doesn't work.</p>