(PECL apc >= 2.0.0)
apc_clear_cache — Clears the APC cache
Clears the user/system cache.
Gibt bei Erfolg TRUE zurück. Im Fehlerfall wird FALSE zurückgegeben.
If cache_type is "user", the user cache will be cleared; otherwise, the system cache (cached files) will be cleared.
It appears for me in PHP 5.2.11/APC 3.1.2 that to clear the opcode cache the argument must be 'opcode'. Having no argument seems to have no effect.