Like TTL
this command returns the remaining time to live of a key that has an
expire set, with the sole difference that TTL
returns the amount of remaining
time in seconds while PTTL
returns it in milliseconds.
In Redis 2.6 or older the command returns -1
if the key does not exist or if the key exist but has no associated expire.
Starting with Redis 2.8 the return value in case of error changed:
- The command returns
-2
if the key does not exist. - The command returns
-1
if the key exists but has no associated expire.
@return
@integer-reply: TTL in milliseconds, or a negative value in order to signal an error (see the description above).
@examples
SET mykey "Hello"
EXPIRE mykey 1
PTTL mykey