regex, check if string does not exist

[jeff205]

I have this regex:

/(\[code\])(.*)(\[b\])(.+)(\[\/b\])(.*)(\[\/code\])/Usi

I need it to check if the open and close ]code[ tags are not there, instead of how it is now where it checks if they are there. Is there a way of doing this with regex?

[.josh]

kwds: negative lookaround

 

or you could just like, do

 

if(!preg_match(....)) { ... }

 

 

[sarathi]

I found that a negative look behind is ?<! and a negative look ahead is ?!, but I can't find the right way to implement them into my code.

/(?<!\[(code|html|css|javascript|php|gml)\])(.*)(\[b\])(.+)(\[\/b\])(.*)(?!\[\/\\2\])/Usi

I've tried this, and few other ways, but I none of them have works, does anyone know how I could correctly implement them to check if there is not a code tag before, and there is not a /code tag after?