TTL

TTL key

Available since:

1.0.0

Time complexity:

O(1)

ACL categories:

@keyspace, @read, @fast,

Returns the remaining time to live of a key that has a timeout. This introspection capability allows a Redis client to check how many seconds a given key will continue to be part of the dataset.

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.

See also the PTTL command that returns the same information with milliseconds resolution (Only available in Redis 2.6 or greater).

Examples

redis> SET mykey "Hello"
Failed to fetch
redis> EXPIRE mykey 10
Failed to fetch
redis> TTL mykey
Failed to fetch

RESP2/RESP3 Reply

One of the following:

• Integer reply: TTL in seconds.
• Integer reply: -1 if the key exists but has no associated expiration.
• Integer reply: -2 if the key does not exist.

History

• Starting with Redis version 2.8.0: Added the -2 reply.