Regex problem

limeonade

Hi folks,

I have a regex problem that I think shouldn't be too tough to figure out but I don't know if I've quite got it.

What I want to do is this: Grab a url from a post, check that it's an internal link before allowing the post.

My problem is with the grabbing part. I'm using a preg_match with this definition of a url
/(http:\/\/)+(www.)?+[a-z0-9-]+.[a-z0-9-.]+[a-z]{2,4}/i
but it does not seem to be working.

Can I get some pointers please?

NogDog

Will all the URLs you're looking for start with "http://", or are you also looking for text that simply starts with "www."? (Also, how about "https://" and/or "ftp://"?)

limeonade

I don't need urls with "https://" and "ftp://"

I think initially I'll try just urls with "http://" but I'll think about adding "www." later.

Is what I have above correct for just the "http://" case?

rmbarnes82

I don't know about the entire regex, but the period's you use '.' need escaping, as they are special characters within regex (they mean match any character), so u'd need (www.) for example, and this applies anywhere else you use the period.

Robin

NogDog

You could try:

'#http://[a-z0-9-]+(\.[a-z0-9-]+)+#i'

Weedpacket

You could also break the job down somewhat; assuming that the URL starts with http:// and ends with a letter, digit or / then match

#http://(.+)(?![a-zA-Z0-9/])#

,
parse_url() the matched string (item 0 in the array so that the "http://" part is included), and then look at the pieces to see if they make sense.