title: How do I grep in a list of files targeted by a previous grep?
body: <p>I am using grep to get a list of files that I want to use for another grep search (and not simply piping it). </p>
  
  <p>For example I got as an output:</p>
  
  <pre><code>file1.h:XXX: linecontent
  file2.h:XXX: linecontent
  file3.h:XXX: linecontent
  file4.h:XXX: linecontent
  </code></pre>
  
  <p>and I want to grep only file1.h, file2.h ... </p>