preg_replace() [function.preg-replace]: Unknown modifier '/' in /home/

Question

in my website i want to replace links with some other link like this

www.abc.com or http://abc.com will be replaced with

http:/

Answer 1

"/\[url]www|http://.([^'\"]*)\[\/url]/iU",
 ^               ^^                  ^

You either need to escape the two // in the middle to \/\/, or, better, use different delimiters for the regex:

"~\[url]www|http://.([^'\"]*)\[/url]~iU",