mcrypt_enc_is_block_algorithm_mode

PHP 4 >= 4.0.2, PHP 5, PHP 7 < 7.2.0, PECL mcrypt >= 1.0.0
mcrypt_enc_is_block_algorithm_mode - Checks whether the encryption of the opened mode works on blocks
Manual

mcrypt_enc_is_block_algorithm_mode( resource$td ): bool

Tells whether the algorithm of the opened mode works on blocks (e.g. false for stream, and true for cbc, cfb, ofb)..

Parameters

td

The encryption descriptor.

Return Values

Returns true if the mode is for use with block algorithms, otherwise it returns false.