title: How to Replace a hash character in file?
body: <p>How can I remove '#' character from file </p>
  
  <pre><code> File Name: /etc/ironman.d
  
   #dir /usr/comicon
   #dir2 /usr/individuality
   #dir3 /usr/land
  </code></pre>
  
  <p>How can I remove '#' character before dir2. There is no way to maintain line number. 
   I tried</p>
  
  <pre><code> dirpath='#dir2 /usr/individuality'
   ${dirpath#/#}
  </code></pre>
  
  <p>But it only removes in $dirpath but not in actual file, if I use above method to remove '#' and add then, I get a duplicate of $dirpath without '#', but I just want single entry without '#' in the file. How do I remove # in place (before dir2)</p>