preg_replace($pattern, $replacement, $subject, $limit = -1, $count = 0);
preg_replace_callback($pattern, $callback, $subject, $limit = -1, $count = 0);
preg_match($pattern, $subject, &$matches, $flags = 0, $offset = 0);
preg_match_all($pattern, $subject, &$matches, $flags = PREG_PATTERN...
