title: sed over multiple files in multiple directories
body: <p>I have the following directory tree:</p>
  
  <pre><code>books&gt;book(i)&gt;cluster.pir
  </code></pre>
  
  <p>where book(i) are a set of sub directories 1 to 1023 each containing a folder called cluster.pir.</p>
  
  <p>The following sed command:</p>
  
  <pre><code>sed -i '/&gt;/d' ./*.pir
  </code></pre>
  
  <p>will delete any line in the file containing '>' for any file with a .pir ext, which is great, but my various .pir files are located in their own book(i) directory. How do I get the command to span across all the directories? I have tried:</p>
  
  <pre><code>find ./*.pir -type f -exec sed -i '/&gt;/d' ./*.pir
  </code></pre>
  
  <p>when starting in the 'book' parent directory, but I get:</p>
  
  <pre><code>find: missing argument to `-exec'
  </code></pre>
  
  <p>does anyone have any thoughts on this?</p>
  
  <p>Thanks.</p>