mcrypt_module_is_block_algorithm This function checks whether the specified algorithm is a block algorithm &warn.deprecated.function-7-1-0; &reftitle.description; boolmcrypt_module_is_block_algorithm stringalgorithm stringlib_dir This function returns &true; if the specified algorithm is a block algorithm, or &false; if it is a stream one. &reftitle.parameters; algorithm The algorithm to check. lib_dir The optional lib_dir parameter can contain the location where the algorithm module is on the system. &reftitle.returnvalues; This function returns &true; if the specified algorithm is a block algorithm, or &false; if it is a stream one.