title: What is the meaning of "0,/xxx" in sed?
body: <p>A sed command used in a script as following:</p>
  
  <pre><code>sed -i "0,/^ENABLE_DEBUG.*/s/^ENABLE_DEBUG.*/ENABLE_DEBUG = YES/" MakeConfig
  </code></pre>
  
  <p>I knows that</p>
  
  <pre><code>s/^ENABLE_DEBUG.*/ENABLE_DEBUG = YES/
  </code></pre>
  
  <p>is to substitutes line prefix </p>
  
  <p><code>ENABLE_DEBUG</code> as <code>ENABLE_DEBUG = YES</code></p>
  
  <p>But no idea about the meaning of</p>
  
  <pre><code>0,/^ENABLE_DEBUG.*/
  </code></pre>
  
  <p>Anyone can help me?</p>