Beginner help: loops, if, else

[Larz60+]

you don't need line 33
I can't understand why it doesn't quit. are you typing ctrl-c?

if you try the script I posted verbatim, you will see that it works.
the only other explanation that I can think of is that one of the modules you're using is servicing interrupts before the sig_capture.
also, if you are not running this from command line, then line 28 will never get executed and must be moved.