How to handle OS signal in a python program?

Question

I am writing a python program which reads from a queue through a infinite while loop. How can I handle signal sent by OS / Keyboard interrupt(CTRL+C) to break from the while loop and close active connections and files and exit the program gracefully instead of killing the process.

while True:
    read_from_file_and_do_something()
    ## Handle a signal of shutdown here.
    ## Send email before exiting.

This program will run as a daemon. Thus would require a signal to be sent.

score 3 · Answer 1 · edited Jul 29 '21 at 05:04

3

I think signal module is what you are looking for,

def handler(signum, frame):
    print 'Signal handler called with signal', signum

signal.signal(signal.SIGABRT, handler)

edited Jul 29 '21 at 05:04

jxramos

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answered Oct 20 '15 at 11:02

nagato

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Where exactly should I use this? Inside the loop? – Siddharth Gupta Oct 20 '15 at 12:02
at ##handle signal `signal.signal(signal.SIGABRT, handler)` and perform aftertask in handler function with exit code – nagato Oct 20 '15 at 12:27
@nagato is there a way to handle multiple signal types with the same handler nicely? (e.g. INT, ABRT, HUP together for example) – Omer Dagan Apr 21 '19 at 10:48

How to handle OS signal in a python program?

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