PING [message]

Returns PONG if no argument is provided, otherwise return a copy of the argument as a bulk. This command is often used to test if a connection is still alive, or to measure latency.

If the client is subscribed to a channel or a pattern, it will instead return a multi-bulk with a “pong” in the first position and an empty bulk in the second position, unless an argument is provided in which case it returns a copy of the argument.

@return

@simple-string-reply, and specifically PONG, when no argument is provided.

@bulk-string-reply the argument provided, when applicable.

@examples

redis> PING
TBD
redis> PING "hello world"