Set Response Status Code

Question

I have an API call for which I need to be able to run some checks and potentially return various status codes. I don't need custom views or anything, I just need to return the proper code. If the user hasn't passed proper credentials, I need to return a 401 status. If they haven't sent a supported request format, I need to return a 400 status.

Because it's an API, all I really want to do is set the response status and exit with a simple, stupid message about why the request failed (probably using a exit). Just enough to get the job done, but I haven't been able to get this to work right. I've tried using PHP's header() and Cake's $this->header() (this is all in the controller), but although I get the exit message, the header shows a 200 OK status.

Using the code below, I get the message, but the header isn't set. What am I missing?

  if( !$this->auth_api() ) {
    header( '401 Not Authorized' );
    exit( 'Not authorized' );
  }

Answer 1

PHP <=5.3

The header() function has a parameter for status code. If you specify it, the server will take care of it from there.

header('HTTP/1.1 401 Unauthorized', true, 401);

PHP >=5.4

See Gajus' answer: https://stackoverflow.com/a/14223222/362536