Quick GPS Startup

-- pastebin run 8fKCR6Eh

if not fs.exists("/startup") then
    term.clear()
    term.setCursorPos(1,2)
    print("No startup found.")
    print("Checking for existing GPS server...")
    supX, supY, supZ = gps.locate(1)
    if supX == nil then
        print("Enter X:")
        write(">")
        repeat
            newX = tonumber(read())
        until newX ~= nil
        print("Enter Y:")
        write(">")
        repeat
            newY = tonumber(read())
        until newY ~= nil
        print("Enter Z:")
        write(">")
        repeat
            newZ = tonumber(read())
        until newZ ~= nil
    else
        print("Oh good, one was found.")
        newX = supX
        newY = supY
        newZ = supZ
    end
    print("Setting up GPS server...")
    file = fs.open("/startup", "w")
    file.writeLine("shell.run('gps host " .. newX .. " " .. newY .. " " .. newZ .. "')")
    file.close()
    os.reboot()
else
    print("Startup already exists. Cancel.")
end
return