PHP - Add link to a URL in a string

Question

I have a function that will add the <a href> tag before a link and </a> after the link. However, it breaks for some webpages. How would you improve this function? Thanks!

function processString($s) 
{
    // check if there is a link

    if(preg_match("/http:\/\//",$s))
    {
        print preg_match("/http:\/\//",$s);


        $startUrl =  stripos($s,"http://");

        // if the link is in between text
        if(stripos($s," ",$startUrl)){
            $endUrl = stripos($s," ",$startUrl);
        }
        // if link is at the end of string
        else {$endUrl = strlen($s);}

        $beforeUrl = substr($s,0,$startUrl);
        $url = substr($s,$startUrl,$endUrl-$startUrl);
        $afterUrl = substr($s,$endUrl);

        $newString = $beforeUrl."<a href=\"$url\">".$url."</a>".$afterUrl;

        return $newString;
    }

    return $s;
}

The regex is a little sloppy, but 99% of my input will have correct URLs if any — AlexBrand, Nov 18 '10 at 16:53
At the beginning you test agains https also, but later you omit the "s". Dont know, if this cause this error, because I also dont know, which pages are broken ;) — KingCrunch, Nov 18 '10 at 16:58
Sorry, I removed the [s] from the regex. How could I include functionality for strings such as "www.google.com", or "https:www.example.com" ? — AlexBrand, Nov 18 '10 at 17:00
"www.google.com" is going to be harder to parse. you need a long regex just to accommodate all TLDs. — bcosca, Nov 18 '10 at 17:03

score 20 · Accepted Answer · edited Jul 24 '14 at 07:22

20

function processString($s) {
    return preg_replace('/https?:\/\/[\w\-\.!~#?&=+\*\'"(),\/]+/','<a href="$0">$0</a>',$s);
}

edited Jul 24 '14 at 07:22

Aron Rotteveel

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answered Nov 18 '10 at 16:57

bcosca

17,371
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I think a "=" is missing: it fails when the url contains get parameters. I just added it after the "&" and now it works: `preg_replace('/https?:\/\/[\w\-\.!~?&=+\*\'"(),\/]+/','$0',$s)` – Narcolessico May 16 '12 at 08:43
4

You forgot about addresses with # inside - so more correct version is `preg_replace('/https?:\/\/[\w\-\.!~#?&=+\*\'"(),\/]+/','$0',$text)` – Roman S Mar 21 '13 at 13:10
I just edited the answer to reflect these two additions. – Aron Rotteveel Jul 24 '14 at 07:23
Do not forget to add the 'u' modifier if your string may contains utf8 characters – Alcalyn Aug 11 '14 at 13:53
I add one more char "%". As result: '/https?:\/\/[\w\-%\.!~#?&=+\*\'"(),\/]+/','$0' – sNICkerssss Jan 11 '18 at 05:49

score 1 · Answer 2 · answered Nov 18 '10 at 16:57

1

It breaks for all URLs that contain "special" HTML characters. To be safe, pass the three string components through htmlspecialchars() before concatenating them together (unless you want to allow HTML outside the URL).

answered Nov 18 '10 at 16:57

tdammers

20,353
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score 1 · Answer 3 · answered Nov 18 '10 at 17:05

1

function processString($s){
  return preg_replace('@((https?://)?([-\w]+\.[-\w\.]+)+\w(:\d+)?(/([-\w/_\.]*(\?\S+)?)?)*)@', '<a href="$1">$1</a>', $s);
}

Found it here

answered Nov 18 '10 at 17:05

egze

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The same scenario I need it in Jquery/Javascript. Can anyone help ? – Yuv Aug 27 '14 at 08:38

PHP - Add link to a URL in a string

3 Answers3

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