PHP Regexp header (session id)

Question

I have the following code :

$html = get_data($url);

I want to extract a session ID from this code, which has the following form :

PHPSESSID=aaabbb123456789;

I'd like to store the session id (only the ID) in a var. I use this regexp :

preg_match('#PHPSESSID=(.+?);#is', $html, $result);

I almost get what I want, but the $result tab contains two strings. Here is the var_dump():

array(2) { [0]=> string(37) "PHPSESSID=aaabbb123456789;" [1]=> string(26) "aaabbb123456789" } 

I would like preg_match() to return only the ID, as in $result[1]. What should I change in the regexp ?

Thanks

Answer 1

The result list of regex matches often has the first result being the entire string. PHP's preg_match() guarantees this as well:

If matches is provided, then it is filled with the results of search. $matches[0] will contain the text that matched the full pattern, $matches[1] will have the text that matched the first captured parenthesized subpattern, and so on.

So you can safely just extract the value as $result[1] without worrying that it might change and cause a warning.