title: piping findstr's output
body: <p>Windows command line, I want to search a file for all rows starting with:</p>
  
  <pre><code># NNN "&lt;file&gt;.inc"
  </code></pre>
  
  <p>where <code>NNN</code> is a number and <code>&lt;file&gt;</code> any string.</p>
  
  <p>I want to use findstr, because I cannot require that the users of the script install ack.</p>
  
  <p>Here is the expression I came up with:</p>
  
  <pre><code>&gt;findstr /r /c:"^# [0-9][0-9]* \"[a-zA-Z0-9_]*.inc" all_pre.txt
  </code></pre>
  
  <p>The file to search is <code>all_pre.txt</code>.</p>
  
  <p>So far so good. Now I want to pipe that to another command, say for example <code>more</code>.</p>
  
  <pre><code>&gt;findstr /r /c:"^# [0-9][0-9]* \"[a-zA-Z0-9]*.inc" all_pre.txt | more
  </code></pre>
  
  <p>The result of this is the same output as the previous command, but with the file name as prefix for every row (all_pre.txt).</p>
  
  <p>Then comes:</p>
  
  <pre><code>FINDSTR: cannot open |
  FINDSTR: cannot open more
  </code></pre>
  
  <p>Why doesn't the pipe work?</p>
  
  <hr>
  
  <p>snip of the content of all_pre.txt</p>
  
  <pre><code># 1 "main.ss"
  # 7 "main.ss"
  # 11 "main.ss"
  # 52 "main.ss"
  # 1 "Build_flags.inc"
  # 7 "Build_flags.inc"
  # 11 "Build_flags.inc"    
  # 20 "Build_flags.inc"
  # 45 "Build_flags.inc(function a called from b)"
  </code></pre>
  
  <hr>
  
  <p>EDIT: I need to escape the dot in the regex also. Not the issue, but worth to mention.</p>
  
  <pre><code>&gt;findstr /r /c:"^# [0-9][0-9]* \"[a-zA-Z0-9_]*\.inc" all_pre.txt
  </code></pre>
  
  <hr>
  
  <p>EDIT after Frank Bollack:</p>
  
  <pre><code>&gt;findstr /r /c:"^# [0-9][0-9]* \"[a-zA-Z0-9_]*\.inc.*" all_pre.txt | more
  </code></pre>
  
  <p>is not working, although (I think) it should look for the same string as before then any character any number of times. That must include the <code>"</code>, right?</p>