Match all valid hyperlinks

Question

I am trying to match ALL hyperlinks, i.e:

• google.com
• www.google.com
• http://google.com

So far this piece of code, does the job pretty good:

        /**
         * Convert links
         */

            $str = preg_replace('$(https?://[a-z0-9_./?=&#-]+)(?![^<>]*>)$i', ' <a href="$1" target="_blank">$1</a> ', $str." ");
            $str = preg_replace('$(www\.[a-z0-9_./?=&#-]+)(?![^<>]*>)$i', '<a href="http://$1"  target="_blank">$1</a> ', $str." ");

But I have stumbled upon two VALID links that does not work. See:

• http://www.sdu.dk/uddannelse/kandidat/cand,-d-,merc/adgang+sept,-d-,+2013/dk+og+ba+ivk+marketing+og+ba+int,-d-,+spr%C3%B8k/valgfagspakke
• http://www.financialtp.com/courses.asp?menu=1&;active=1&gclid=CJGd0JPUjL4CFSENcwodM1wAyA

Any solution that would find ALL matching links?

Answer 1

Only adding few chars inside your character class and making it case insensitive takes it all the way. But not pretty to look at :)

(?i)(https?://[a-z0-9_./?=&#-,;-]+)(?![^<>]*>)

Answer 2

I ended up using this:

/**
 * Convert URL to links
 */

    function make_links($text) {
      return  preg_replace(
         array(
           '/(?(?=<a[^>]*>.+<\/a>)
                 (?:<a[^>]*>.+<\/a>)
                 |
                 ([^="\']?)((?:https?|ftp|bf2|):\/\/[^<> \n\r]+)
             )/iex',
           '/<a([^>]*)target="?[^"\']+"?/i',
           '/<a([^>]+)>/i',
           '/(^|\s)(www.[^<> \n\r]+)/iex',
           '/(([_A-Za-z0-9-]+)(\\.[_A-Za-z0-9-]+)*@([A-Za-z0-9-]+)
           (\\.[A-Za-z0-9-]+)*)/iex'
           ),
         array(
           "stripslashes((strlen('\\2')>0?'\\1<a href=\"\\2\">\\2</a>\\3':'\\0'))",
           '<a\\1',
           '<a\\1 target="_blank">',
           "stripslashes((strlen('\\2')>0?'\\1<a href=\"http://\\2\">\\2</a>\\3':'\\0'))",
           "stripslashes((strlen('\\2')>0?'<a href=\"mailto:\\0\">\\0</a>':'\\0'))"
           ),
           $text
       );
    }

Seems to be working pretty good so far.