#include <memcached.h>
memcached_return_t
memcached_delete (memcached_st *ptr,
const char *key, size_t key_length,
time_t expiration);
memcached_return_t
memcached_delete_by_key (memcached_st *ptr,
const char *master_key, size_t master_key_length,
const char *key, size_t key_length,
time_t expiration);
Expiration works by placing the item into a delete queue, which means that it won't possible to retrieve it by the ``get'' command, but ``add'' and ``replace'' command with this key will also fail (the ``set'' command will succeed, however). After the time passes, the item is finally deleted from server memory.
Please note the the Danga memcached server removed support for expiration in the 1.4 version.
If you are using the non-blocking mode of the library, success only means that the message was queued for delivery.