Howto:Create a new Nasal module

Note  Since $FG_ROOT is considered read-only, use $FG_ROOT/Nasal just for testing.

This tutorial will document all the steps involved in creating a new Nasal module. Nasal is FlightGear's built-in scripting language.

• Create a new plain text file under $FG_ROOT/Nasal/<module_name>.nas
• Replace <module_name> with the name for your new module (for example test)
• Paste the following code into this file using a text editor:

# test.nas (save in $FG_ROOT/Nasal)
var mycode = func() {
    print("My test module got loaded!");
};
setlistener("/sim/signals/nasal-dir-initialized", mycode);

This piece of code defines a new function named mycode that just prints a message to the console (terminal/shell window).

Note  This code does not output anything to the FlightGear simulator screen, only the console window.

Then you can use io.include("Nasal/test.nas"); to import the module.