A handy function for PHP that checks if a string is actually something that has been serialized

gistfile1.php

<?php
/**
 * Checks if data is serialized
 * @param mixed $data
 */

public function is_serialized($data) {
    if (!is_string( $data)) {
        return false;
    }
    $data = trim($data);
    if ('N;' == $data) {
        return true;
    }
    if (!preg_match('/^([adObis]):/', $data, $badions)) {
        return false;
    }
    switch ($badions[1]) {
        case 'a' :
        case 'O' :
        case 's' :
            if (preg_match( "/^{$badions[1]}:[0-9]+:.*[;}]\$/s", $data)) {
                return true;
            }
            break;
        case 'b' :
        case 'i' :
        case 'd' :
            if (preg_match("/^{$badions[1]}:[0-9.E-]+;\$/", $data)) {
                return true;
            }
            break;
    }
    return false;
}