How to pass aruments to a Lua function from command line?

Question

I have the following test.lua script:

print("before function")
function calc(n)
    print("in function")
    print(10*n)
end

I'm trying to execute it from the command line using lua test.lua calc 10, but the only output I get is:

before function

What should I do to get the following output:

before function
in function
100

Note that your function never runs at all. If you want lua to do stuff with the command line arguments, your code needs to read the arguments and work things out itself — Eric, May 24 '15 at 18:08
Maybe related to: https://stackoverflow.com/questions/2945819/interactive-lua-command-line-arguments — JDong, May 24 '15 at 18:08
@JDong, the solution there seems to work only in interactive mode. — Sparkler, May 24 '15 at 18:09
Then is this what you are looking for: http://torch5.sourceforge.net/manual/LuaManual-6.html ? — JDong, May 24 '15 at 18:11

score 1 · Answer 1 · answered May 24 '15 at 18:35

1

For the following code,

m = {}

print("before function")
function m.calc(n)
    print("in function")
    print(10*n)
end

m[arg[1]](arg[2])

the command lua test.lua calc 10 would output:

before function
in function
100

answered May 24 '15 at 18:35

Sparkler

2

Why complicate things with a table `m`? – lhf May 24 '15 at 19:41
@lhf, it couldn't get it to work otherwise (assuming I would have additional functions in the same file). – Sparkler May 24 '15 at 21:59
You can use `_G[ arg[1] ]( select(2, unpack(arg)) )` in that case without involving `m`. The `select` `unpack` stuff lets you supply an arbitrary number of arguments. – greatwolf May 25 '15 at 03:42
1

`_G[...](select(2,...))` :) – moteus May 25 '15 at 12:22
@moteus, could you please make this into a fully working example? – Sparkler May 26 '15 at 00:38
1

test.lua `function add(a,b) print(a+b) end _G[...](select(2,...))` invoke `test add 10 20` – moteus May 26 '15 at 06:48

1 Answers1