Get os and arch for Onset

getos.lua

function getOS()
    local raw_os_name, raw_arch_name = '', ''
            -- Unix-based OS
            raw_os_name = io.popen('uname -s','r'):read('*l')
            raw_arch_name = io.popen('uname -m','r'):read('*l')
            if raw_os_name == nil and raw_arch_name == nil then
               -- Windows
                local env_OS = os.getenv('OS')
                local env_ARCH = os.getenv('PROCESSOR_ARCHITECTURE')
                if env_OS and env_ARCH then
                    raw_os_name, raw_arch_name = env_OS, env_ARCH
                end
            end
    raw_os_name = (raw_os_name):lower()
    raw_arch_name = (raw_arch_name):lower()

    local os_patterns = {
        ['windows'] = 'Windows',
        ['linux'] = 'Linux',
        ['mac'] = 'Mac',
        ['darwin'] = 'Mac',
        ['^mingw'] = 'Windows',
        ['^cygwin'] = 'Windows',
        ['bsd$'] = 'BSD',
        ['SunOS'] = 'Solaris',
    }
    
    local arch_patterns = {
        ['^x86$'] = 'x86',
        ['i[%d]86'] = 'x86',
        ['amd64'] = 'x86_64',
        ['x86_64'] = 'x86_64',
        ['Power Macintosh'] = 'powerpc',
        ['^arm'] = 'arm',
        ['^mips'] = 'mips',
    }

    local os_name, arch_name = 'unknown', 'unknown'

    for pattern, name in pairs(os_patterns) do
        if raw_os_name:match(pattern) then
            os_name = name
            break
        end
    end
    for pattern, name in pairs(arch_patterns) do
        if raw_arch_name:match(pattern) then
            arch_name = name
            break
        end
    end
    return os_name, arch_name
end
local os_name, arch_name = getOS()
print(os_name .. " " .. arch_name)