Find url from string with php

A working method for linking with http/https/ftp/ftps/scp/scps: $newStr = preg_replace('!(http|ftp|scp)(s)?:\/\/[a-zA-Z0-9.?&_/]+!', "<a href=\"\\0\">\\0</a>",$str);

I strongly advise NOT linking when it only has a dot, because it will consider PHP 5.2, ASP.NET, etc. links, which is hardly acceptable.

Update: if you want www. strings as well, take a look at this.

If you want to detect something like stackoverflow.com, then you're going to have to check for all possible TLDs to rule out something like Web 2.0, which is quite a long list. Still, this is also going to match something as ASP.NET etc.

The regex would looks something like this:

$hypertext = preg_replace(
    '{\b(?:http://)?(www\.)?([^\s]+)(\.com|\.org|\.net)\b}mi',
    '<a href="http://$1$2$3">$1$2$3</a>',
    $text
);

This only matches domains ending in .com, .org and .net... as previously stated, you would have to extend this list to match all TLDs