- str_replace: documentation ( source)
- preg_replace: documentation ( source)
<?php
$input = '<img src="THE SOURCE HERE" alt="" title="bla bla bla">%2F';
$t = $input;
$t = preg_replace("/[<].*src=/", "", $t);
$t = preg_replace("/\" alt=\"\" title.*[>]/", "", $t);
$t = str_replace("%2F", "/", $t);
echo $t;