title: how do I detect OS X in my .vimrc file, so certain configurations will only apply to OS X?
body: <p>I use my .vimrc file on my laptop (OS X) and several servers (Solaris &amp; Linux), and could hypothetically someday use it on a Windows box.  I know how to detect unix generally, and windows, but how do I detect OS X?    (And for that matter, is there a way to distinguish between Linux and Solaris, etc.  And is there a list somewhere of all the strings that 'has' can take?  My <a href="http://www.google.com/search?hl=en&amp;client=firefox-a&amp;hs=tsl&amp;rls=org.mozilla%3Aen-US%3Aunofficial&amp;q=.vimrc+has+unix+win32+gui_running+vms&amp;aq=f&amp;aqi=&amp;aql=&amp;oq=&amp;gs_rfai=" rel="noreferrer">Google-fu</a> turned up nothing.)</p>
  
  <p>For instance, I'd use something like this:</p>
  
  <pre><code>if has("mac")
    " open a file in TextMate from vi: "
    nmap mate :w&lt;CR&gt;:!mate %&lt;CR&gt;
  elseif has("unix")
    " do stuff under linux and "
  elseif has("win32")
    " do stuff under windows "
  endif
  </code></pre>
  
  <p>But clearly "mac" is not the right string, nor are any of the others I tried.</p>
  
  <hr>
  
  <p>UPDATE:
  The answer below ("macunix") seems fairly clearly like it <em>should</em> work, but for some reason it doesn't.  (Perhaps Apple didn't compile vim properly to respond to this? Seems unlikely.)</p>
  
  <p>At any rate I guess I need to shift the focus of the question: does anyone have a solution that will achieve the same ends?  (That is, successfully detecting that the .vimrc file is being used on Mac OS X.)</p>