# mcrypt_module_self_test

(PHP 4 >= 4.0.2, PHP 5)

mcrypt_module_self_test — This function runs a self test on the specified module

### Description

bool mcrypt_module_self_test ( string `$algorithm` [, string `$lib_dir` ] )

This function runs the self test on the algorithm specified. The optional `lib_dir` parameter can contain the location of where the algorithm module is on the system.

The function returns `TRUE` if the self test succeeds, or `FALSE` when if fails.

Example#1 mcrypt_module_self_test() example

`<?php
var_dump(mcrypt_module_self_test(MCRYPT_RIJNDAEL_128)) . "\n";
var_dump(mcrypt_module_self_test(MCRYPT_BOGUS_CYPHER));
?>`

The above example will output:

    bool(true)
    bool(false)