Update expiration on a key
SYNOPSIS
- #include <libmemcached/memcached.h>
- Compile and link with -lmemcached 
- 
memcached_return_t memcached_touch(memcached_st *ptr, const char *key, size_t key_length, time_t expiration)
- Parameters:
- ptr -- pointer to initialized - memcached_ststruct
- key -- the key to touch 
- key_length -- the length of - keywithout any terminating zero
- expiration -- new expiration as a unix timestamp or as relative expiration time in seconds 
 
- Returns:
- memcached_return_tindicating success
 
- 
memcached_return_t memcached_touch_by_key(memcached_st *ptr, const char *group_key, size_t group_key_length, const char *key, size_t key_length, time_t expiration)
- Parameters:
- ptr -- pointer to initialized - memcached_ststruct
- group_key -- the - keynamespace
- group_key_length -- the length of - group_keywithout any terminating zero
- key -- the key to touch 
- key_length -- the length of - keywithout any terminating zero
- expiration -- new expiration as a unix timestamp or as relative expiration time in seconds 
 
- Returns:
- memcached_return_tindicating success
 
DESCRIPTION
memcached_touch() is used to update the expiration time on an existing key.
memcached_touch_by_key() works the same, but it takes a master key
to find the given value.
RETURN VALUE
A value of type memcached_return_t is returned.
On success that value will be MEMCACHED_SUCCESS.
Use memcached_strerror() to translate this value to a printable
string.