var URL = /(https?://|ftps?://)?((d{1,3}.d{1,3}.d{1,3}.d{1,3})(:[0-9]+)?|(localhost)(:[0-9]+)?|([w]+.)(S+)(w{2,4})(:[0-9]+)?)(/?([w#!:.?+=&%@!-/]+))?/ig;

/**
*JavaScrit 版本
* 将URL地址转化为完整的A标签链接代码
*/
var replaceURLToLink = function (text) {
    text = text.replace(URL, function (url) {
                                  var urlText = url;
                                  if (!url.match('^https?://')) {
                                  url = 'http://' + url;
                                }
                           return '' + urlText + '';
                          });
                          return text; };

/**
* PHP 版本 在 Silva 代码的基础上修改的
* 将URL地址转化为完整的A标签链接代码
*/
/** =============================================
NAME : replace_URLtolink()
VERSION : 1.0
AUTHOR : J de Silva
DESCRIPTION : returns VOID; handles converting
URLs into clickable links off a string.
TYPE : functions
============================================= */

function replace_URLtolink($text) {
// grab anything that looks like a URL...
$urls = array();

// build the patterns
$scheme = '(https?://|ftps?://)?';
$www = '([w]+.)';
$local = 'localhost';
$ip = '(d{1,3}.d{1,3}.d{1,3}.d{1,3})';
$name = '([w0-9]+)';
$tld = '(w{2,4})';
$port = '(:[0-9]+)?';
$the_rest = '(/?([w#!:.?+=&%@!-/]+))?';
$pattern = $scheme.'('.$ip.$port.'|'.$www.$name.$tld.$port.'|'.$local.$port.')'.$the_rest;
$pattern = '/'.$pattern.'/is';

// Get the URLs
$c = preg_match_all($pattern, $text, $m);

if ($c) {
$urls = $m[0];
}

// Replace all the URLs
if (! empty($urls)) {
foreach ($urls as $url) {
$pos = strpos('http://', $url);

if (($pos && $pos != 0) || !$pos) {
$fullurl = 'http://'.$url;
} else {
$fullurl = $url;
}

$link = ''.$url.'';

$text = str_replace($url, $link, $text);
}
}

return $text;
}