Question

The following process does not continue after running kill -SIGCONT pid from another terminal.

#include <stdio.h>

int main(int argc, char *argv[])
{
    printf("paused\n");
    pause();
    printf("continue\n");

    return 0;
}

I expect the program to continue after sending the signal and printing “continue”. How come this doesn’t work as expected?

Answer 1

pause() is documented to

cause the calling process (or thread) to sleep until a signal is delivered that either terminates the process or causes
the invocation of a signal-catching function.

But SIGCONT only continues a process previously stopped by SIGSTOP or SIGTSTP.

So, you might want to try:

 kill(getpid(), SIGSTOP);

Instead of your pause()

Also, you might want to look at sigsuspend().