Available since: 7.0.0
Time complexity: O(N+M) where N is the number of provided keys and M is the number of elements returned.
Pops one or more elements from the first non-empty list key from the list of provided key names.
BLMPOP are similar to the following, more limited, commands:
RPOPwhich take only one key, and can return multiple elements.
BRPOPwhich take multiple keys, but return only one element from just one key.
BLMPOP for the blocking variant of this command.
Elements are popped from either the left or right of the first non-empty list based on the passed argument. The number of returned elements is limited to the lower between the non-empty list's length, and the count argument (which defaults to 1).
Array reply: specifically:
nilwhen no element could be popped.