What is Redis ?
We all might be familiar with [Redis] .
For those who are not - It's a "NoSQL" key-value data store. More precisely, it is a data structure server.
To read more - [Redis-Wiki]
Do [try redis] it has a nice interactive tutorial.
To install and setup redis on your machine see [how-to-install-and-use-redis]
What is LUA ?
LUA is an embeddable scripting language. About LUA - http://www.lua.org/about.html
Redis >= 2.6 supports embedded scripting language.
Lets give a try to it.
To run a script in redis we need to use [EVAL] command.
A Lua script file should be saved with .lua extension
local msg = "Hello, world!" return msg
Save this file locally as hello.lua and run it like so:
redis-cli EVAL "$(cat hello.lua)" 0
Running this will print “Hello, world!”. The first argument of EVAL is the complete lua script — here we’re using the cat command to read the script from a file. The second argument is the number of Redis keys that the script will access. Our simple “Hello World” script doesn’t access any keys, so we use 0.