r/lua

Sometimes I have to automate a basic task, such as running some commands on files in my music library, bulk renaming, moving things, etc; and like anyone, I tend to try and use Bash for things like that, because that's what I was taught. The problem is that I don't like Bash scripting at all and I have to look up the stupid syntax for every little thing every god damn time. From what I've seen, other shells aren't too much better in my opinion, and in general, I actually don't like relying on shell commands within my scripts for things that would be simpler in a 'normal' programming language.

I've tried using Python as a replacement, but I don't like having to make a venv. It's bulky and annoying. I'd like to just have one script file I can run in one command whenever and not have to go through hoops.

I've been eyeing Lua just because it sounds cool but I've never had a reason to actively learn it. Would it be fit for this usage? Or is it solely a language for "project use", so to say?

I’m currently on day 4 of learning Roblox scripting/Luau and I’ve been following a beginner tutorial series while also experimenting with my own scripts outside the tutorials. So far I understand basics like variables, loops, events, touch detection, humanoids, functions, conditions, and simple mechanics like kill bricks, speed boosts, transparency changes, etc. I’ve also started debugging my own scripts instead of just copying code.

I want to start making small projects to improve instead of jumping straight into my dream game too early. What would be a good first game/project to make that helps me learn scripting and game development fundamentals without being too overwhelming?

sup, names Jack and i been recently dreaming of making my own roblox games after seeing my favorite youtuber making a viral one, i do find roblox studio familiar but i dont have former experience of scripting AT ALL! My plan is to watch tutorials, study them and then in 3-4 weeks when i have summer vacation i can spend those 1.5 months to make a game. How did you guys learn? Do you have any tips?

Some context. I'm making an articulated arm with create Aeronautics controlled by computers.

3 motors to get maximum movement. Highly inefficient, cool as fck

My problem resides in the way i've been controlling the motors.
All 3 motors have individual computers with modems, all ready to recieve instructions from the main pc. They are supposed to receive an instruction, and sleep continuously while the motor is active, and only at the end of the movement will they send a reply to the main pc, which will trigger the next commands.
The arm is supposed to be slow, it's supposed to move only one motor at a time (intentional).
When i make a simple basic list of modem,transmits() ,the arm behaves as intended.

this proof of concept worked as intended

This above is a very simple instruction to make the arm move slightly. My problem was this was ugly and tedious to expand. So i made a much cleaner(?) and more customisable version that was supposed to make it MUCH more simple to make new movement prompts later down the line.

function movementControl(a)
  local actionCount = 0
  local directionValue = 0
  local turnorder = {{1,2},{5,6},{3,4},{1,2},{3,4},{5,6},{1,2}}

  for i, angle in ipairs(a) do
    if angle == 'forward' then
      directionValue = -1

    elseif angle == 'backward' then
      directionValue = 1

    elseif angle =='motorstart' then
      rs.setOutput("back",true)
      sleep(3)

    elseif angle == 'motorstop' then
      rs.setOutput("back",false)
      sleep(5)

    elseif type(angle)=="number" then
      actionCount = actionCount + 1
      modem.transmit(turnorder[actionCount][1],turnorder[actionCount][2],{angle,directionValue})
      sleep(0.1)
      modem.open(turnorder[actionCount][2])
      local event, side ,channel, replyChannel, message, distance = os.pullEvent("modem_message")
      modem.close(turnorder[actionCount][2])
      sleep(0.1)

    end
  end



end


local harvestwheat1 = {'forward',30,20,23,'motorstart',30,'motorstop','backward',23,20,60}
local harvestwheat2 = {'forward',100,20,23,'motorstart',40,'motorstop','backward',23,20,140}
local harvestcarrot1 = {'forward',110,70,47,'motorstart',20,'motorstop','backward',47,70,130}


movementControl(harvestwheat1)

Now the actual problem is that the os.pullEvent i do when in my for loop dont seem to actually pause the computer. The loop kinda just continues on without waiting for the response from the motors.
Is there a specificity to Lua that i'm not getting (not likely) ? is there a specificity that my not good at coding ass doesn't understand (much more likely) ?

Ty for the help, and if people have better ways of doing any of this i might cave in and just redo the code from scratch with some suggestions ><

local gear = peripheral.wrap("right")
local modem = peripheral.wrap("left")
modem.open(1)


while true do
  
  local event, side ,channel, replyChannel, message, distance = os.pullEvent("modem_message")


  gear.rotate(message[1],message[2])


  while gear.isRunning() do
    sleep(0.5)
  end
  modem.transmit(replyChannel,20,gear.isRunning())


end

bonus : this is the code im using on the pc at the motors.

Hey everyone! I’m not really experienced with pirating or anything like that, but before I had a BeamNG manifest file and just dragged it into SteamTools, and it basically handled everything for me. The website I used to extract the files stopped working though, so now I’m not sure what to use anymore. I’m trying to do the same thing for FH6, but I can’t find any good websites or tools.

For those who aren't familiar, Turtle Graphics came out of work in the '60s, '70s, and '80s by Seymour Papert, Wally Feurzuig, Cynthia Solomon, and others on the LOGO programming language. It teaches math and programming in a visual, intuitive, embodied way (long before those terms were marketing buzzwords).

Python ships with a version of turtle graphics which uses the TKinter UI library by default, but some great web versions exist, including pythonsandbox.com/turtle and WebTigerPython. YouTube has terrific examples of what you can make with the Python library.

I believe Turtle Graphics is (still) underrated as a learning and teaching tool for anything quantifiable. The original book associated with it, Mindstorms: Children, Computers, and Powerful Ideas is still worth reading and still ahead of its time. It's available online as a free PDF, from Papert's estate, at Bret Victor's worrydream.com and elsewhere. (I have no association with any of these projects).

This project is my first serious undertaking with AI-assisted engineering, but I'm reasonably pleased with it so far. There's a web-based version (Github) and a desktop port (Github) as well, for those who prefer their own IDE setup.

Both projects are roughly feature-equivalent but still under active development and a bit rough around the edges, as you can see.

I hope this project is useful to you, either now or in its future, completed state.

The Lua API is as close to the Python API as I can get it, although naturally there are some differences between languages. If you're already familiar with the Python library (or familiar enough with Python to understand some of the online turtle examples) this would be a good way to become familiar with Lua.

Happy coding!

EDIT: There's a wonderful, mind-bending textbook by Harold Abelson and Andrea DiSessa called Turtle Geometry: The Computer as a Medium for Exploring Mathematics that explains turtle coding in-depth, with a whole host of cool, trippy graphics and very readable pseudocode for implementing them. (Part of the inspiration behind this port is how closely Lua mirros the syntax of those examples and of some of the original LOGO design principles). It is also available free online via MIT's Direct reader.

Here are some Github gists with ready Lua sample code for some of the animations:

The "spiro" program

A general "polygon" program — one of my favorites.

if btn(⬆️) then
grav=grav-1
if timer=0 then
grav=grav+1
timer=timer+4
else
timer=timer-1
end

TIL: yes, this can be done. And yes, it is completely safe: you cannot cause UB with this.

local ffi = require("ffi")

--Declaring our ffi struct that will hold the data.
ffi.cdef([[
  typedef struct {
    void* data_ref;
  } LuaTable;
]])

--Can be any lua type stored on heap (table, function, thread, userdata).
local data = function()
  print("hello world")
end

--We get the actual address and store it in a lua number.
local data_ptr_id = tonumber(tostring(data):match("0x%x+"))

--The external storage. That's the only way to get the object back from C land.
local storage = {}
storage[data_ptr_id] = data

--(You can set __mode for this table so that it stores values weakly. But then all ffi structs wouldn't be able to "own" the data inside them.
--To actually own the data and correctly let go of it, you'd need to make a reference counter primitive, like a shared_ptr<T> in C++ or Rc<T> in Rust.
--This counter will also need to be an ffi struct so that we can set a ffi.gc() callback for it.
--The callback would do `storage[data_ptr_id] = nil`, but *only* when there are no longer any references to it. 
--So it basically lets go of the data and to let GC manage it. Remember that regular tables could also store our object!
--You'll need to make sure that each reference counter primitive (lets just call it Rc) holds a unique object, or, in other words, there can't be two Rcs holding the same object. 
--Otherwise, after any of them get freed, the object will get prematurely released.)

--Here's our ffi struct.
local table_ffi = ffi.new("LuaTable", ffi.cast("void*", data_ptr_id))

--And here's how we get it back.
local also_data = storage[tonumber(ffi.cast("uintptr_t", table_ffi.data_ref))]

--If the object's been collected by the GC already, we'll just get a nil, so no use after free opportunities.

--Enjoy!
also_data()

Hello everyone this is my 2nd post on this subreddit about this topic and got alot of responses but this post is slightly different

Currently I've been trying to hire a developer part time for a project of mine that has been in the works since May 2025 and development has been pretty slow currently as its just me and my friend who is developing the server and i wanted to make an update post honestly asking if anyone who is a developer would be interested on working with us for a small percentage, small payment per task/task list currently I'm putting in around $100-200 a month into the server for only a few months as i do not have much money and the main reason why I'm having issues with finding developers is i understand majority of developers now use ai but my goal with this project is to not have ai used at all when it comes to the coding for the server which does spend more time on creating scripts but i have had very bad experiences with vibe coders such as being scammed, the scripts made by AI cause numerous amount of bugs the list goes on. If this is something that interests you and would like to learn more about the project and goals please contact me on discord.

This post is NOT to throw shade at anyone who uses AI to code i just have had very bad experiences with AI.

Discord - naqs871

So I was thinking about learning Lua to make a passion project that Ive been thinking about for a while and wanted to know if there’s anything I should know before hand that will make my experience easier.