Software Lua - libraries

[StefanE]

Hi everybody,

I am trying to get data out of Orbiter (2010 P1) to a 2nd Computer via RS232 or TCPIP, using the lua-interface.


There are libraries for serial communication available (e.g. luars232), but the Orbiter-Lua-Interface does not seem to recognize them. As soon as I put a line "rs232 = require ('luars232') in my script, I get the usual Execution Error. Somehow I have to tell Orbiter where to look for lua-libraries, but where? I did not find any hint. Maybe the Orbiter-Lua-Interface does not accept external libraries? I did not find a single example of a lua-File within the Orbiter 2010 P1 Installation which uses the 'require'-statement. It should be mentioned, that a full lua-Installation is running on the same computer without the a.m. restriction.

Kind regards
StefanE

P.S.

Please do not consider any alternatives or workarounds like "use orbconnect" etc.

 

[Urwumpe]

AFAIR, you just need to extend the module search path for Lua to make it find the proper modules.

I would need to look into my Lua book at home to tell you something more accurate though.

 

[StefanE]

Hi Urwumpe

Not being lazy I googled for global variables in context with orbiter, and found the following:
"To determine its path, require first checks the global variable LUA_PATH". Problem is, that with a clean install of orbiter, there is no sign of a global variable in the Control Panel in connection with Orbiter (assuming Global variable means "Umgebungsvariable" in a german XP edition). Global Variables for Lua appear only with a full Lua Installation

 

[Urwumpe]

Hi Urwumpe

Not being lazy I googled for global variables in context with orbiter, and found the following:
"To determine its path, require first checks the global variable LUA_PATH". Problem is, that with a clean install of orbiter, there is no sign of a global variable in the Control Panel in connection with Orbiter (assuming Global variable means "Umgebungsvariable" in a german XP edition). Global Variables for Lua appear only with a full Lua Installation

You mistake something there: Lua also has global variables in its own script context. Which you can manipulate to your advantage or horror.

So: By the book:

require looks into the global variable "package.path", which is initialized to the environment variable "LUA_PATH". If no suitable named .lua file is found there, it looks for a C-Module under the global variable "package.cpath", which is initialized to the environment variable "LUA_CPATH".

So, in your case, if you want to load a C-module in Lua, you should either set "LUA_CPATH" and try that, or append package.cpath to contain a path to your C-module.

 

[StefanE]

Hi Urwumpe

After several hours of unsuccessful testing i came upon the possibility to let me show the value of environment variables.

local text
text = os.getenv('LUA_PATH')
term.out(text)

This gives me: ;;C:\Programme\Lua\5.1\lua\?.luac

The same with LUA_CDIR: nil
The same with LUA_LDIR: nil
The same with LUA_INIT: nil
The same with LUA_CPATH_DEFAULT: nil

So it seems the variables we need aren't initialized?

Kind regards
StefanE

 

[Urwumpe]

No surprise, since it should be "LUA_CPATH" without any default.

 

[StefanE]

The same with LUA_CPATH: nil

 

[Urwumpe]

The same with LUA_CPATH: nil

Then try it with the package.cpath variable, if that can be set. Remember that Lua is embedded in Orbiter, but still, the environment variables should have a small effect.

 

[StefanE]

Hi Urwumpe

I think the solution to this problem is an entirely different one.

When I did the first Orbiter2010-Install I allowed it to install in the default directory, which is "\Eigene Dateien" , resulting in very long path names. I removed Orbiter2010 and did a new install with the Custom-Option and chose C:\Orbiter2010. From then on it worked, including all paths which previously read "nil" now populated with meaningfull directories.

Nevertheless thank you very much.

Kind regards
StefanE

 

[Urwumpe]

From then on it worked, including all paths which previously read "nil" now populated with meaningfull directories.

Oh, thats a pretty strange behavior.