How can I determine the OS of the system from within a Lua script?

Question

Ok I need to determine the system\'s OS from a Lua script, but Lua as such has no API for this, so I use os.getenv() and query enviromental variables. On Windows checking the en

Answer 1

When lua is compiled, it is configured slightly differently depending on what operating system it is compiled for.

Many of the strings which are set in the 'package' module can thus be used to distinguish which system it was compiled for.

For instance, when lua loads C-based modules which are distributed as dynamic libraries, it has to know the extension used for those libraries, which is different on each OS.

Thus, you can use a function like the following to determine the OS.

local BinaryFormat = package.cpath:match("%p[\\|/]?%p(%a+)")
if BinaryFormat == "dll" then
    function os.name()
        return "Windows"
    end
elseif BinaryFormat == "so" then
    function os.name()
        return "Linux"
    end
elseif BinaryFormat == "dylib" then
    function os.name()
        return "MacOS"
    end
end
BinaryFormat = nil