auto-link-text.php

<?php

// taken from http://code.google.com/p/auto-link-rewriter-php/

function auto_link_text($text) {
        $pattern  = '#\b(([\w-]+://?|www[.])[^\s()<>]+(?:\([\w\d]+\)|([^[:punct:]\s]|/)))#';
        return preg_replace_callback($pattern, 'auto_link_text_callback', $text);
}

function auto_link_text_callback($matches) {
        $max_url_length = 50;
        $max_depth_if_over_length = 2;
        $ellipsis = '&hellip;';
        
        $url_full = $matches[0];
        $url_short = '';
        
        if (strlen($url_full) > $max_url_length) {
                $parts = parse_url($url_full);
                $url_short = $parts['scheme'] . '://' . preg_replace('/^www\./', '', $parts['host']) . '/';
        
                $path_components = explode('/', trim($parts['path'], '/'));
                foreach ($path_components as $dir) {
                        $url_string_components[] = $dir . '/';
                }
                
                if (!empty($parts['query'])) {
                        $url_string_components[] = '?' . $parts['query'];
                }
                
                if (!empty($parts['fragment'])) {
                        $url_string_components[] = '#' . $parts['fragment'];
                }

                for ($k = 0; $k < count($url_string_components); $k++) {
                        $curr_component = $url_string_components[$k];
                        if ($k >= $max_depth_if_over_length || strlen($url_short) + strlen($curr_component) > $max_url_length) {
                                if ($k == 0 && strlen($url_short) < $max_url_length) {
                                        // Always show a portion of first directory
                                        $url_short .= substr($curr_component, 0, $max_url_length - strlen($url_short));
                                }
                                $url_short .= $ellipsis;
                                break;
                        }
                        $url_short .= $curr_component;
                }
                
        } else {
                $url_short = $url_full;
        }
        
        return "<a rel=\"nofollow\" href=\"$url_full\">$url_short</a>";
}