local WIN32, DIR_SEP

if os.getenv("WINDIR") then
    WIN32 = true
    DIR_SEP = "\\"
else
    WIN32 = false
    DIR_SEP = "/"
end

function os.mkdir(dir)
    local f = io.open(dir..DIR_SEP..".dummy")
    if f then
        f:close()
    else
        if WIN32 then
            dir = dir:gsub("/", "\\")
        else
            dir = dir:gsub("\\", "/")
        end
        if  minetest.mkdir then
            minetest.mkdir(dir)
        else
            os.execute('mkdir "'..dir..'"')
        end
        local f = io.open(dir..DIR_SEP..".dummy", "w")
        if f then
            f:write("DO NOT DELETE!!!\n")
            f:close()
        end
    end
end