$re = '/^[\w\d\/\.\-\+]+(?:\s?;?(\s+)?((?:boundary|charset)\s?=\s?[\'\"\w\d\.\-]+)?;?(\s+)?)?(?:\s?(?:gzip|deflate|br|,)+\s?;?(\s+)?)?$/m';
$str = 'application/x-www-form-urlencoded
application/x-www-form-urlencoded;
application/x-www-form-urlencoded; charset=utf-8;
application/x-www-form-urlencoded; charset=utf-8;gzip,deflate;
application/x-www-form-urlencoded; charset=utf-8;gzip,deflate,br; ';
preg_match_all($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