title: How to remove leading whitespace from each line in a file
body: <p>I have a file that looks something like this:</p>
  
  <pre><code>for (i = 0; i &lt; 100; i++)
      for (i = 0; i &lt; 100; i++)
    for (i = 0; i &lt; 100; i++)
         for (i = 0; i &lt; 100; i++)
       for (i = 0; i &lt; 100; i++)
             for (i = 0; i &lt; 100; i++)
  for (i = 0; i &lt; 100; i++)
  </code></pre>
  
  <p>I want it to look like this (remove indentations):</p>
  
  <pre><code>for (i = 0; i &lt; 100; i++)
  for (i = 0; i &lt; 100; i++)
  for (i = 0; i &lt; 100; i++)
  for (i = 0; i &lt; 100; i++)
  for (i = 0; i &lt; 100; i++)
  for (i = 0; i &lt; 100; i++)
  for (i = 0; i &lt; 100; i++)
  </code></pre>
  
  <p>How can this be done (using <code>sed</code> maybe?)?</p>