title: Limit sed to certain character range in a line
body: <p>I have a large one line file containing hex codes and I'd like to use sed to find patterns within certain character range of that line.</p>
  
  <p>So far i've tryed this witout succes something like </p>
  
  <pre><code>echo abc123abc123abc123 | sed 's/^\(123\{8,14\}\)/\456/g'
  </code></pre>
  
  <p>I'd like it to output </p>
  
  <pre><code>abc123abc456abc123   
  </code></pre>
  
  <p>(replace the pattern 123 only if found between the characters position 8 to 14) </p>
  
  <p>Thanks for your help!</p>