io support and command line args

steve64

It's not clear to me if the 'io' library is going to be supported.
Currently I'm trying to use existing Lua packages, like an XML parser ([Login to see the link]) and I'm getting lot of problems due to missing 'io'. Should I replace all uses of 'io' with LuaRT File and console APIs ?

Also, I'm not sure the management of command line arguments works properly.
According to the official Lua reference: "Lua collects all command-line arguments in a global table called arg. The script name goes to index 0, the first argument after the script name goes to index 1, and so on. Any arguments before the script name (that is, the interpreter name plus its options) go to negative indices"

But in LuaRT:

everything seems shifted right by one index, when running a program from the IDE (no debug)
even worse when the IDE starts the program in debug mode (a temporary path appears in the arg table)
the exe file is passed at index 0, followed by arguments (if any), this is more in line with the official specs

Samir

Hi steve64,

LuaRT don't support io module from PUC Lua.
You have two choice when using a third party library that uses the io module :

Rewrite the third party library by replacing io functions by LuaRT equivalent (mainly sys.File object)
Or use the runtime Lua54.dll in thebin\std\ folder that provides better compatibility with PUC-Lua (as it includes io and os modules)

steve64 According to the official Lua reference: "Lua collects all command-line arguments in a global table called arg. The script name goes to index 0, the first argument after the script name goes to index 1, and so on. Any arguments before the script name (that is, the interpreter name plus its options) go to negative indices"

You are right , with LuaRT :

arg[0] contains interpreter fullpath, for example"C:\LuaRT\bin\luart.exe"
arg[1] contains the first argument (the current script fullpath)
arg[2...] contains any other arguments provided after the script fullpath
There is no negatives index

If it provides compatibility issues it might change to a more near bahavior as for PUC Lua

steve64

I'm using LuaRT 1.4.0 and I noticed that the first command line argument passed as arg[2] includes a leading space (at least when running the script from the IDE)

Samir

Hi steve64,
Thank you for this report I will check this 👍🏻

Samir

You were right, it's a LuaRT Studio bug (command line parameters are working as expected with LuaRT interpreters).
It's fixed and will be available in next release.

ruby

► io.write(1)
1["pretty.lua"]:35: attempt to get length of a FILE* value (local 'value')

I think pretty.lua should be more strict with value types.

only handle known types as string or number etc.

Samir

Yes the next version will handle those kind of userdata custom values 👍🏻

cos00kun

hi.
How can the file path outside the directory be represented?
For example, let's say we have a game folder and there are two more folders, Source and Image. Now my code file main.lua file is inside the Source folder. If I want to define the images in the Image folder in my main.lua file, how should I define a path?
file.fullpath , directory.fullpath doesn't provide exactly that or I haven't been able to do it yet 🙂

ruby

use .. to get relative parent folder

cos00kun

oh so good how I forgot. thanks [Login to see the link] 🙂

Samir

You can also use the [Login to see the link] property

cos00kun

a thank you too. 🙂