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.
    
     
例子 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)); ?>
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       The above example will output:
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