BRPOP

Syntax

BRPOP key [key ...] timeout

Time complexity: O(N) where N is the number of provided keys.

ACL categories: @write, @list, @slow, @blocking

BRPOP is a blocking list pop primitive. It is the blocking version of RPOP because it blocks the connection when there are no elements to pop from any of the given lists. An element is popped from the tail of the first list that is non-empty, with the given keys being checked in the order that they are given.

See the BLPOP documentation for the exact semantics, since BRPOP is identical to BLPOP with the only difference being that it pops elements from the tail of a list instead of popping from the head.

Return

Array reply: specifically:

• A nil multi-bulk when no element could be popped and the timeout expired.
• A two-element multi-bulk with the first element being the name of the key where an element was popped and the second element being the value of the popped element.

Examples

dragonfly> DEL list1 list2
(integer) 0
dragonfly> RPUSH list1 a b c
(integer) 3
dragonfly> BRPOP list1 list2 0
1) "list1"
2) "c"