- parse_str: documentation ( source)
- urldecode: documentation ( source)
- parse_url: documentation ( source)
<?php
$src = 'http://www.my.com/api.php?url='.'http%253A%252F%252Fwww.my.com%252Fapi.php%253Fkey1%253Dxxx%2526key2%253Dxxx';
$src = parse_url( urldecode($src) );
parse_str($src['query']);
echo $url;