- var_dump: documentation ( source)
- preg_match_all: documentation ( source)
<?php
$matches = [];
$reg = '/(?:^|(?:\s*\,\s*))([^\x00-\x20\(\)<>@\,;\:"\/\[\]\?\=\{\}\x7F]+)(?:\=(?:([^\x00-\x20\(\)<>@\,;\:"\/\[\]\?\=\{\}\x7F]+)|(?:"((?:[^"\]|\.)*)")))?/';
preg_match_all($reg, 'User-Agent, Accept', $matches, PREG_SET_ORDER);
var_dump($matches);
echo 'aaa' ;
var_dump('bb');