Linux / C如何正确结束命令行程序

Question

I have a program that runs on the Linux command line. It allocates some memory, opens some file descriptors, etc. I'd like a good way to be able to have user input stop the program while still doing cleanup and not interrupting some file read/write. What is the proper way to do this? So far, I've been using CTRL+C to stop the program, but I feel like that doesn't do the cleanup properly, and that doesn't give my program the chance do a log file write indicating that it is closing. Currently I'm doing this: -Set STDIN to non-blocking (So that the program doesn't hang waiting for input)

while(loop_variable != 'q') {
loop_variable = getchar();
...
}

Any suggestions?

Answer 1

William Pursell commented that you can catch SIGINT.

Here's how you would implement cleanup when SIGINT is caught.

First, you define the cleanup function. In the function you do all the house cleaning.

void cleanup(int signum) {
    ... //all house cleaning steps like deleting files, closing file descriptors
}

In the main() function, you can call signal() and pass the name of the function cleanup and the associated signal to catch. You can catch as many types of signal appropriate for your user actions.

signal(SIGINT, cleanup);
signal(SIGQUIT, cleanup);