$re = '/[?&](abcustomerid=\d+)/';
$str = '/the/stucture/blah.php?timeout=300&abcustomerid=53122&customer=zxyi
/some/other/struct/pagehere.php?today=Thursday&abcustomerid=241&count=54
/blah/blah/tendid.php?abcustomerid=12525';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php