COMMAND GETKEYS
Time complexity: O(N) where N is the number of arguments to the command
Returns of keys from a full Redis command.
COMMAND shows some commands as having movablekeys meaning the entire command must be parsed to discover storage or retrieval keys. You can use to discover key positions directly from how Redis parses the commands.
Array reply: list of keys from your command.
*Examples
redis> COMMAND GETKEYS EVAL "not consulted" 3 key1 key2 key3 arg1 arg2 arg3 argN
redis> COMMAND GETKEYS SORT mylist ALPHA STORE outlist
redis>