title: endian.h not found on mac osx
body: <p>I meet some trouble when I compile some C code on my mac which give me this error :</p>
  
  <p><strong>fatal error: 'endian.h'
        file not found</strong></p>
  
  <p>I did some google search about this problem.It seems like mac os x does not have header files like "endian.h", we have to create this file manually.</p>
  
  <p>Then, I found this <a href="http://www.opensource.apple.com/source/CarbonHeaders/CarbonHeaders-18.1/Endian.h" rel="noreferrer">http://www.opensource.apple.com/source/CarbonHeaders/CarbonHeaders-18.1/Endian.h</a> which might be the file I am looking for but not sure.</p>
  
  <p>But more troubles are coming.. where should I put this file?  </p>
  
  <p><strong>The file /usr/include does not exist.</strong></p>
  
  <p>These are the folders in my /usr directory:</p>
  
  <p><strong>X11       bin     libexec     share
  X11R6       lib     sbin        standalone</strong></p>
  
  <p>Could anyone help me to check the correctness of the endian.h file I found and tell me where to put this file in my mac please?</p>