lpushx.3valkey - Man Page

Prepends one or more elements to a list only when the list exists.

Synopsis

LPUSHX key element [element...]

Description

Inserts specified values at the head of the list stored at key, only if key already exists and holds a list. In contrary to LPUSH, no operation will be performed when key does not yet exist.

Reply

valkey-protocol(7) Integer reply: the length of the list after the push operation.

Complexity

O(1) for each element added, so O(N) to add N elements when the command is called with multiple arguments.

Acl Categories

@fast @list @write

History

Examples

127.0.0.1:6379> LPUSH mylist "World"
(integer) 1
127.0.0.1:6379> LPUSHX mylist "Hello"
(integer) 2
127.0.0.1:6379> LPUSHX myotherlist "Hello"
(integer) 0
127.0.0.1:6379> LRANGE mylist 0 -1
1) "Hello"
2) "World"
127.0.0.1:6379> LRANGE myotherlist 0 -1
(empty array)

See Also

blmove(3valkey), blmpop(3valkey), blpop(3valkey), brpop(3valkey), lindex(3valkey), linsert(3valkey), llen(3valkey), lmove(3valkey), lmpop(3valkey), lpop(3valkey), lpos(3valkey), lpush(3valkey), lrange(3valkey), lrem(3valkey), lset(3valkey), ltrim(3valkey), rpop(3valkey), rpush(3valkey), rpushx(3valkey)

Info

2024-09-23 8.0.0 Valkey Command Manual