(PHP 4 >= 4.0.2)

mcrypt_module_is_block_algorithm_mode -- This function returns if the the specified module is a block algorithm or not


bool mcrypt_module_is_block_algorithm_mode ( string mode [, string lib_dir])

This function returns TRUE if the mode is for use with block algorithms, otherwise it returns FALSE. (eg. FALSE for stream, and TRUE for cbc, cfb, ofb). The optional lib_dir parameter can contain the location where the mode module is on the system.