Parsing HTTP status code

Question

Hello,

I am using PHP to parse the numeric portion of the HTTP status code response. Given a standard "HTTP/1.1 200 OK" response, I'd use:

$data = explode(' ', "HTTP/1.1 200 OK");
$code = $data[1];

I'm not an expert on HTTP. Would I ever encounter a response where the code is not at the position of $data[1] as in the above example? I just want to be sure that this method of delimiting the response code will always work for any response.

Thanks, Brian

Answer 1

No, you would never encounter a response (if it's a proper HTTP response) which has a different format. See the HTTP RFC (2616).

Answer 2

No, what you are doing is OK if all you want is the numeric. If however you want the message as well, you'll end up splitting it too, ie.

HTTP/1.1 404 Not Found

Answer 3

No if the webserver respect the standards doing an explode and caching the second item of the array is fine

if you really wants to be sure use a regular expression

i.e.

preg_match('|HTTP/\d\.\d\s+(\d+)\s+.*|',$subject,$match);
var_dump($match[1]);

Cheers

Answer 4

When in doubt, check the spec. The spec in this case, for HTTP/1.1, is RFC2616. In Section 6.1, it describes the Status-Line, the first component of a Response, as:

Status-Line = HTTP-Version SP Status-Code SP Reason-Phrase CRLF

That is - a single ASCII space (SP) must separate the HTTP-Version and the Status-Code - and if you check the definition of HTTP-Version (in Section 3.1) it cannot include a space, and neither can the Status-Code.

So you are good to go with that code.