Redis Lua examples

eval-hello.sh

redis-cli EVAL "$(cat hello.lua)" 0

eval-incr-and-stor.sh

redis-cli EVAL "$(cat incr-and-stor.lua)" 2 links:counter links:urls http://malcolmgladwellbookgenerator.com/

gistfile1.txt

These are examples for a blog post on www.redisgreen.net

hello.lua

local msg = "Hello, world!"
return msg

hincrex.lua

if redis.call("HEXISTS", KEYS[1], ARGV[1]) == 1 then
  return redis.call("HINCR", KEYS[1], ARGV[1])
else
  return nil
end

incr-and-stor-expanded.lua

local link_id = redis.call("INCR", "links:counter")
redis.call("HSET", "links:urls", link_id, "http://malcolmgladwellbookgenerator.com")
return link_id

incr-and-stor.lua

local link_id = redis.call("INCR", KEYS[1])
redis.call("HSET", KEYS[2], link_id, ARGV[1])
return link_id

increx.lua

if redis.call("EXISTS",KEYS[1]) == 1 then
  return redis.call("INCR",KEYS[1])
else
  return nil
end

json-get.console

redis-cli set apple '{ "color": "red", "type": "fruit" }'
=> OK

redis-cli eval "$(cat json-get.lua)" 1 apple type
=> "fruit"

json-get.lua

if redis.call("EXISTS", KEYS[1]) == 1 then
  local payload = redis.call("GET", KEYS[1])
  return cjson.decode(payload)[ARGV[1]]
else
  return nil
end

msgpack-get.lua

if redis.call("EXISTS", KEYS[1]) == 1 then
  local payload = redis.call("GET", KEYS[1])
  return cmsgpack.unpack(payload)[ARGV[1]]
else
  return nil
end

notruncfloat.lua

local indiana_pi = 3.2
redis.call("SET", "pi", indiana_pi)
return redis.call("GET", "pi")

script-load.console

redis-cli SCRIPT LOAD "return 'hello world'"
=> "5332031c6b470dc5a0dd9b4bf2030dea6d65de91"

redis-cli EVALSHA 5332031c6b470dc5a0dd9b4bf2030dea6d65de91 0
=> "hello world"

truncfloat.lua

local indiana_pi = 3.2
return indiana_pi