84KaliPleXon3/alobbs-macchanger ? reverse-engineered prompt

Build me a small command line utility that makes it easy to change the MAC address of a network interface.

I want it to work like a real system tool, so it should be able to show the current MAC address, generate a new random one, restore the original one, and let me set a custom address if I want to. It should handle common errors cleanly, like when an interface does not exist or when I do not have permission to change it.

Please make it feel like a proper GNU style program, with a help screen, a man page, and basic documentation. If there are any platform or system details you need to check, look up the current docs online if needed. Keep it focused on the utility itself, not a big app.