parsing - How to best parse 1 HTTP header VALUE in PHP? -

i have important, detailed http header in response want parse value of details:

digest realm="my very, cool site", nonce="a8w/7adzbaa=ffc2afd053c8802dd64be69b985f38c85ec29607", algorithm=md5, domain="/", qop="auth" 

it's comma-separated, it's quoted, values can contain ,. there's "digest " that's not part of key="value"-pairs. (i can assume first part ("digest") never contain spaces, shouldn't hard.

i'm thinking sure way byte-by-byte parse , " , ,, that's lot of work.

it might i'm missing useful php spl function. tried http_parse_headers(), that's unstandard , don't have that.

you can use regular expression:

function parseheader($theheadervalue /* without digest: part */) {   if (preg_match_all("'(?<variable>[a-z0-9\_]+)\=(?<delimiter>[\"\']?)(?<value>.*?)(?<!\\\)\k<delimiter>(?:\s*(?:,|$))'isux", $theheadervalue, $matches) , !empty($matches['variable'])) {     $result = array();     foreach ($matches['variable'] $index=>$key) $result[$key] = $matches['value'][$index];     return $result;   } else return array(); }