Linkify

linkify.php

<?php

/**
 * linkify
 * 
 * @link Github: https://gist.github.com/jrobinsonc/e79578c41ca48bac9bde
 * @param  string $value
 * @param  array  $protocols
 * @param  array  $attributes
 * @param  string $mode
 * @return string
 */
function linkify($value, $protocols = array('http', 'https', 'mail', 'twitter'), $attributes = array(), $mode = 'normal')
{
    $attr = '';
    foreach ($attributes as $key => $val)
        $attr = ' ' . $key . '="' . htmlentities($val) . '"';

    $links = array();

    $value = preg_replace_callback('~(<a .*?>.*?</a>|<.*?>)~i', function ($match) use (&$links) { return '<' . array_push($links, $match[1]) . '>'; }, $value);

    foreach ((array)$protocols as $protocol) 
    {
        switch ($protocol) 
        {
            case 'http':
            case 'https': 
                $value = preg_replace_callback($mode != 'all' ? '~(?:(https?)://([^\s<]+)|(www\.[^\s<]+?\.[^\s<]+))(?<![\.,:])~i' : '~([^\s<]+\.[^\s<]+)(?<![\.,:])~i', function ($match) use ($protocol, &$links, $attr) { if ($match[1]) $protocol = $match[1]; $link = $match[2] ?: $match[3]; return '<' . array_push($links, '<a' . $attr . ' href="' . $protocol . '://' . $link . '">' . $link . '</a>') . '>'; }, $value); 
                break;

            case 'mail': 
                $value = preg_replace_callback('~([^\s<]+?@[^\s<]+?\.[^\s<]+)(?<![\.,:])~', function ($match) use (&$links, $attr) { return '<' . array_push($links, '<a' . $attr . ' href="mailto:' . $match[1] . '">' . $match[1] . '</a>') . '>'; }, $value); 
                break;

            case 'twitter': 
                $value = preg_replace_callback('~(?<!\w)[@#](\w++)~', function ($match) use (&$links, $attr) { return '<' . array_push($links, '<a' . $attr . ' href="https://twitter.com/' . ($match[0][0] == '@' ? '' : 'search/%23') . $match[1] . '">' . $match[0] . '</a>') . '>'; }, $value); 
                break;

            default: 
                $value = preg_replace_callback($mode != 'all' ? '~' . preg_quote($protocol, '~') . '://([^\s<]+?)(?<![\.,:])~i' : '~([^\s<]+)(?<![\.,:])~i', function ($match) use ($protocol, &$links, $attr) { return '<' . array_push($links, '<a' . $attr . ' href="' . $protocol . '://' . $match[1] . '">' . $match[1] . '</a>') . '>'; }, $value); 
                break;
        }
    }

    return preg_replace_callback('/<(\d+)>/', function ($match) use (&$links) { return $links[$match[1] - 1]; }, $value);
}