Question

Right now I have a function connected to SIGARLM that goes off after 1 second and will re-alarm itself to go off in another second everytime. There’s a test in the logic of the SIGALRM function I wrote to see if a certain timeout has been reached and when it does I need it to kill a function that’s running. Does anybody know how I can do this?

I forgot to mention: in the function that needs to be killed it waits on scanf() and the function needs to die even if scanf() hasn’t returned yet.

Answer 1

One approach that might be worth looking into is using select to poll stdin and see if any data is ready. select lets you wait for some period of time on a file descriptor, controlling when you can be interrupted and by what, and seems like it’s perfect here. You could just sit in a loop waiting for up to a second, then failing gracefully if no data is available. That way, SIGALRM wouldn’t need to kill the function; it would take care of that all by itself.