title: grep --include command doesn't work in OSX Zsh
body: <p>I am following the best answer on <a href="https://stackoverflow.com/questions/16956810/finding-all-files-containing-a-text-string-in-linux/16957078#16957078">How do I find all files containing specific text on Linux?</a> to search string in my project.</p>
  
  <p>This is my command <code>grep --include=*.rb -rnw . -e "pattern"</code></p>
  
  <p>Zsh tells me that <code>zsh: no matches found: --include=*.rb</code></p>
  
  <p>It seems that grep doesn't  support <code>--include</code> option.</p>
  
  <p>When I type <code>grep --help</code>, it returns</p>
  
  <pre><code>usage: grep [-abcDEFGHhIiJLlmnOoPqRSsUVvwxZ] [-A num] [-B num] [-C[num]]
      [-e pattern] [-f file] [--binary-files=value] [--color=when]
      [--context[=num]] [--directories=action] [--label] [--line-buffered]
      [--null] [pattern] [file ...]
  </code></pre>
  
  <p>no <code>--include</code> here.</p>
  
  <p>Is my grep version too old? Or is there something wrong with my command?</p>