Listens for messages published to channels.
SUBSCRIBE channel
[channel…]
Subscribes the client to the specified channels.
Once the client enters the subscribed state it is not supposed to
issue any other commands, except for additional SUBSCRIBE,
SSUBSCRIBE, PSUBSCRIBE,
UNSUBSCRIBE, SUNSUBSCRIBE,
PUNSUBSCRIBE, PING, RESET and
QUIT commands. However, if RESP3 is used (see
HELLO) it is possible for a client to issue any commands
while in subscribed state.
Note that RESET can be called to exit subscribed
state.
For more information, see Pub/sub.
When successful, this command doesn’t return anything. Instead, for
each channel, one message with the first element being the string
subscribe is pushed as a confirmation that the command
succeeded.
O(N) where N is the number of channels to subscribe to.
@pubsub @slow
PSUBSCRIBE, PUBLISH, PUBSUB, PUBSUB CHANNELS, PUBSUB HELP, PUBSUB NUMPAT, PUBSUB NUMSUB, PUBSUB SHARDCHANNELS, PUBSUB SHARDNUMSUB, PUNSUBSCRIBE, SPUBLISH, SSUBSCRIBE, SUNSUBSCRIBE, UNSUBSCRIBE.