Question

I want to filter the input text if it’s got A URL inside it.
By URL I mean that every thing that corresponds to a valid internet address like www.example.com, example.com, http://www.example.com, http://example.com/foo/bar.

I think I’ve gotta use regular expressions and the preg_match function so I need the correct regexp pattern for this purpose.
I’d be very grateful if anybody could give me that.

Answer 1

This article has a nice regex for matching urls: http://daringfireball.net/2010/07/improved_regex_for_matching_urls

For PHP you would need to escape the regex properly, for example like this:

$text = "here is some text that contains a link to www.example.com, and it will be matched.";
preg_match("/(?i)\b((?:[a-z][\w-]+:(?:\/{1,3}|[a-z0-9%])|www\d{0,3}[.]|[a-z0-9.\-]+[.][a-z]{2,4}\/)(?:[^\s()<>]+|\(([^\s()<>]+|(\([^\s()<>]+\)))*\))+(?:\(([^\s()<>]+|(\([^\s()<>]+\)))*\)|[^\s`!()\[\]{};:'\".,<>?«»“”‘’]))/", $text, $matches);
var_dump($matches);