是什么：

　　进程间的一种消息通信模式：发送者（pub）发送消息，订阅者（sub）接收消息。

　　订阅/发布消息图

先订阅后发布后才能收到消息

1.可以一次性订阅多个，SUBSCRIBE c1 c2 c3

2.消息发布，PUBLISH c2 hello-redis

先订阅

127.0.0.1:6379> SUBSCRIBE c1 c2 c3
Reading messages... (press Ctrl-C to quit)
1) "subscribe"
2) "c1"
3) (integer) 1
1) "subscribe"
2) "c2"
3) (integer) 2
1) "subscribe"
2) "c3"
3) (integer) 3
1) "message"

发布

127.0.0.1:6379> PUBLISH c2 hello-redis
(integer) 1
127.0.0.1:6379> PUBLISH c1 hello1122
(integer) 1
127.0.0.1:6379>

收到消息

127.0.0.1:6379> SUBSCRIBE c1 c2 c3
Reading messages... (press Ctrl-C to quit)
1) "subscribe"
2) "c1"
3) (integer) 1
1) "subscribe"
2) "c2"
3) (integer) 2
1) "subscribe"
2) "c3"
3) (integer) 3
1) "message"
2) "c2"
3) "hello-redis"
1) "message"
2) "c1"
3) "hello1122"

======================

3.订阅多个，通配符*，PSUBSCRIBE new*

4.收取消息，PUBLISH new1 redis2015

127.0.0.1:6379> PSUBSCRIBE new*
Reading messages... (press Ctrl-C to quit)
1) "psubscribe"
2) "new*"
3) (integer) 1
1) "pmessage"
2) "new*"
3) "new1"
4) "redis2015"
1) "pmessage"
2) "new*"
3) "new2"
4) "redis2016"

127.0.0.1:6379> PUBLISH new1 redis2015
(integer) 1
127.0.0.1:6379> PUBLISH new2 redis2016
(integer) 1
127.0.0.1:6379>