redis_subscribe/4

Availability::- use_module(library(redis)).(can be autoloaded)

[det]redis_subscribe(+Redis, +Channels, -Id, +Options)

Subscribe to one or more Redis PUB/SUB channels. This predicate creates a thread using thread_create/3 with the given Options. Once running, the thread listens for messages. The message content is a string or Prolog term as described in redis/3. On receiving a message, the following message is broadcasted:

redis(Id, Channel, Data)

If redis_unsubscribe/2 removes the last subscription, the thread terminates.

To simply print the incomming messages use e.g.

?- listen(redis(_, Channel, Data),
          format('Channel ~p got ~p~n', [Channel,Data])).
true.
?- redis_subscribe(default, test, Id, []).
Id = redis_pubsub_3,
?- redis(publish(test, "Hello world")).
Channel test got "Hello world"
1
true.

`Id`	is the thread identifier of the listening thread. Note that the `Options` `alias(Name)` can be used to get a system wide name.