mcrypt_enc_is_block_mode
    (PHP 4 >= 4.0.2)
mcrypt_enc_is_block_mode -- Checks whether the opened mode outputs blocks
Description
bool 
mcrypt_enc_is_block_mode ( resource td)
     This function returns TRUE if the mode outputs blocks of bytes or      FALSE if it outputs bytes. (eg. TRUE for cbc and ecb, and FALSE for cfb and      stream).