(PECL apc >= 3.0.13) Stores a file in the bytecode cache, bypassing all filters.

(PECL apc >= 3.0.0) Fetch a stored variable from the cache

(PECL apc >= 3.1.1) Decrease a stored number

(PECL apc >= 3.1.4) Checks if APC key exists

(PECL apc >= 3.1.1) Deletes files from the opcode cache

(PECL apcu >= 4.0.0) Fetch a stored variable from the cache

(PECL apcu >= 4.0.0) Checks if entry exists

(PECL apc >= 2.0.0) Retrieves cached information from APC's data store

(PECL apc >= 3.0.0) Defines a set of constants for retrieval and mass-definition

(PECL apcu >= 4.0.0) Increase a stored number