redisUsage of LUA scripts in Redis

redis-cli EVAL "return redis.call('get', KEYS[1]) + redis.call('get', KEYS[2]);" 2 key1 key2ctrl + cgithub

`redis-cli` executes Redis command in bash	`EVAL` evaluates specified LUA code
`redis.call` call Redis method	`'get'` gets value by Redis key
`KEYS[1]` refers to first argument passed to `EVAL` command (`key1`)	`KEYS[2]` refers to second argument passed to `EVAL` command (`key2`)
`2 key1 key2` number of arguments we'll pass to the command and the arguments themselves

redis-cli EVAL "return redis.call('get', KEYS[1]) + redis.call('get', KEYS[2]);" 2 key1 key2

(integer) 138