note 60493 deleted from ref.pcre by colder

Note Submitter: alexbodn at 012 dot n@t dot il ---- here is an annotation to my note from 28-Apr-2005 03:52, due to the welcome contribution of dipesh khakhkhar: Here is a small function to determine whether a string is a preg expression. Please note, that a dot '.' character in a regexp may match any character, including a dot, thus a string containing a dot may well be interpreted as an ordinary string, or a regexp. function preg_ispreg($str) { $prefix = ""; $sufix = ""; if ($str[0] != '^') $prefix = '^'; if ($str[strlen($str) - 1] != '$') $sufix = '$'; $estr = preg_replace("'^/'", "\\/", preg_replace("'([^/])/'", "\\1\\/", $str)); if (@preg_match("/".$prefix.$estr.$sufix."/", $str, $matches)) return strcmp($str, $matches[0]) != 0; return true; }