Handler functions that terminate the program are typically used to cause orderly cleanup or recovery from program error signals and interactive interrupts.
The cleanest way for a handler to terminate the process is to raise the same signal that ran the handler in the first place. Here is how to do this:
volatile sig_atomic_t fatal_error_in_progress = 0;
void
fatal_error_signal (int sig)
{
/* Since this handler is established for more than one kind of signal,
it might still get invoked recursively by delivery of some other kind
of signal. Use a static variable to keep track of that. */
if (fatal_error_in_progress)
raise (sig);
fatal_error_in_progress = 1;
/* Now do the clean up actions:
- reset terminal modes
- kill child processes
- remove lock files */
...
/* Now reraise the signal. Since the signal is blocked,
it will receive its default handling, which is
to terminate the process. We could just call
exit or abort , but reraising the signal
sets the return status from the process correctly. */
raise (sig);
}