daemonから子プロセスへSIGUSR1を送信

gistfile1.c

#include <sys/types.h>
#include <signal.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <syslog.h>

int catch_sigusr1 = 0;
int catch_sigbus = 0;

void sig_handler(int signum) {
	if (signum == SIGUSR1) {
		catch_sigusr1++;
	}
}

void sigsender(pid_t pid) {
	sleep(3);

	if (kill(pid, SIGUSR1)) {
		printf("*** error kill() %d.\n", errno);
	}
}

void sigwaiter() {
	syslog(LOG_INFO, "sigwaiter: start\n");

	while(1) {
		sleep(1);
		if (catch_sigusr1) {
			printf("...killed.\n");
			syslog(LOG_INFO, "sigwaiter: killed sigusr1=%d\n", catch_sigusr1);
			exit(0);
		}
	}
}

void set_sigaction(int signum, void (*handler)(int)) {
	struct sigaction act;

	act.sa_handler = handler;
	sigemptyset (&act.sa_mask);
	act.sa_flags = SA_RESTART | SA_NOCLDSTOP;

	if (sigaction(SIGUSR1, &act, NULL)) {
		printf("*** error sigaction() %d.\n", errno);
	}

}

int main()
{
	pid_t pid_wait;

	/* sig setup */
	set_sigaction(SIGUSR1, &sig_handler);

	if (daemon(1, 0)) {
		printf("*** daemon() error.\n");
	}

	/* wait */
	pid_wait = fork();
	if (pid_wait == 0) {
		sigwaiter();
	}

	/* sender */
	printf("pid_wait=%d\n", pid_wait);
	sigsender(pid_wait);

	waitpid(pid_wait, NULL, 0);
	printf("Bye!");
}