added SIGTERM signal handler for main loop

[bernhofer]

I've noticed that using the shell approach in a systemd service, as discussed in this issue, results in Python subprocesses not shutting down when running systemctl restart or systemctl stop (e.g., during fan curve updates). To address this, I have implemented a signal handler to ensure a graceful shutdown (and restoration of defaults) when a SIGTERM signal is received.

To make this fix effective, the ExecStart in the service configuration also needs to be updated:
ExecStart=/bin/bash -c 'cd /path/to/nvidia_fan_control_linux && source fan/bin/activate && python nvidia_fan_control.py'

[RoversX]

Sorry for the delay; I've been busy lately. Thanks for optimizing the code and adding signal handling! I haven't personally tested it as a service, but I hope it works smoothly for those who do. I assume you've tested it as well? 👏

[bernhofer]

No problem at all! Yes, I went ahead and tested it as a service with signal handling. The fan curves can be modified and applied by restarting the service. 👍