In Redis, the LPOS
command returns the index of matching elements inside a list.
Tag: lists
Redis BLMOVE Command Explained
In Redis, the BLMOVE
command is the blocking variant of LMOVE
.
When the specified list contains elements, it atomically returns and removes either the first or last element of the given source list, and pushes the element at either the first or last element of the specified destination list. Whether it’s the first or last element depends on the arguments passed to the command.
Continue readingRedis LMOVE Command Explained
In Redis, the LMOVE
command atomically returns and removes either the first or last element of the given source list, and pushes the element at either the first or last element of the specified destination list.
Whether it’s the first or last element depends on the arguments passed to the command.
The LMOVE
command can be used in place of the RPOPLPUSH
command, which has been deprecated since Redis 6.2.0.
Redis LINDEX Command Explained
In Redis, the LINDEX
command returns the element at the specified index at the specified key.
Redis LLEN Command Explained
In Redis, the LLEN
command returns the length of the list stored at the specified key.
Redis LRANGE Command Explained
In Redis, the LRANGE
command returns the specified elements of the list stored at the specified key.
The command requires us to specify a start and stop position for the elements to return. These are zero based indexes, so 0
is the first element in the list.
We can specify -1
for the last element in the list.
Redis LMPOP Command Explained
In Redis, the LMPOP
command pops one or more elements from the first non-empty list key from the list of provided key names.
The LMPOP
command is similar to LPOP
, except that it can accept multiple keys. It’s also similar to BLPOP
(which accepts multiple keys), except that it can pop multiple elements (BLPOP
can only pop one element).
Redis BLMPOP Command Explained
In Redis, the BLMPOP
command is the blocking variant of LMPOP
.
Just like the LMPOP
command, BLMPOP
pops one or more elements from the first non-empty list key from the list of provided key names. However, unlike LMPOP
, if all lists are empty, BLMPOP
blocks the connection until another client pushes to it or until the timeout
(a double value specifying the maximum number of seconds to block) elapses.
Redis BRPOP Command Explained
In Redis, the BRPOP
command is the blocking variant of the RPOP
command. It blocks the connection when there are no elements to pop from any of the given lists.
The way the command works is that 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. When there are no elements to pop from any of the lists, it blocks the connection.
Continue readingRedis RPOP Command Explained
In Redis, the RPOP
command removes and returns the last elements of the list stored at the specified key.
By default, the command pops a single element from the end of the list. However, we have the option of passing a second argument that specifies how many elements to pop.
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