Question

I’m having issues with a pair of functions I have that allow a user to make links without prior html knowledge using a [link] and [/link] set. All was well until I began testing it for accidentals such as spaces before and after the link. Now it’s timing out on my server which is set to a 30 second max processing time.

The user can enter a total of 5000 characters which is a healthy page worth of text that these functions have to look through. However, when the user correctly types the code in (without spaces) it does not tax the server and my page pops up in a fraction of a second like it should. If one of the [link] [/link] is missing, the while loop exits – nothing happens. It’s only when the link is typed with spaces like this:

[link] http://www.google.com[/link%5D
–or–
[link]www.google.com [/link]

both of which time out the server with this error (slightly modified path):

Fatal error: Maximum execution time of 30 seconds exceeded in /home/example/thiscode.php on line 18

[link]www.google.com[/link] does not time out nor does:
[link]www. google.com[/link] which simply doesn’t get recognized as a valid html link but does get the anchor tag put with it properly.

Any thoughts? Code hoy!

function my_link($snip)
{

    // Locate '[link]'
    $pos = stripos($snip, '[link]');

    // Strips off everything before [link]
    $str = substr($snip, $pos);

    // Removes [link] from $str
    $str = substr($str, 6);

    // Trim off any accidental whitespace BEFORE the link
    $str = ltrim($str);

    // Locate the end delimiter '[/link]'
    $pos_2 = stripos($str, '[/link]');

    // Cut off everything after and including '[/link]'
    $str = substr($str, 0, $pos_2);

    // Trim any accidental whitespace AFTER the link
    $str = rtrim($str);

    // Construct valid HTML link using content given
    if(strpos($str, 'http://') === FALSE) {
        $link = '<a href="http://'.$str.'">'.$str.'</a>';
    }else{
        $link = '<a href="'.$str.'">'.$str.'</a>';
    }

    // Replace the old [link]content[/link] with our newly constructed link
    $new_input = str_replace('[link]'.$str.'[/link]', $link, $snip);

    return $new_input;

}

function making_links($input)
{

    // Loop through $input as many times as [link] & [/link] pairs occur
    while(strpos($input, '[link]') && strpos($input, '[/link]')) {

        $input = my_link($input);

    }

    return $input;

}

Thanks in advance to anyone who can help me!

Answer 1

You could try something like this however it’s likely to suffer performance issues given a suitably large block of text. Couldn’t be worse than what you’ve got there

$input = preg_replace('@\[link\]\s*(https?://)?(.+?)\s*\[/link\]@i', '<a href="http://$2">$2</a>', $input);

For a more robust solution, you should look into lexical analysis.