title: Delete whitespace in each begin of line of file, using bash
body: <p>How i can delete whitespace in each line of file, using bash
  For instance, file1.txt. Before:</p>
  
  <pre><code>  gg g
   gg g
  t  ttt
  </code></pre>
  
  <p>after:</p>
  
  <pre><code>gg g
  gg g
  t  ttt
  </code></pre>