interprocess.c

// C program to implement sighup(), sigint()
// and sigquit() signal functions
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <unistd.h>

// function declaration
void sighup();
void sigint();
void sigquit();

// driver code
void main()
{
	int pid;

	/* get child process */
	if ((pid = fork()) < 0) {
		perror("fork");
		exit(1);
	}

	if (pid == 0) { /* child */
		signal(SIGHUP, sighup);
		signal(SIGINT, sigint);
		signal(SIGQUIT, sigquit);
		for (;;)
			; /* loop for ever */
	}

	else /* parent */
	{ /* pid hold id of child */
		printf("\nPARENT: sending SIGHUP\n\n");
		kill(pid, SIGHUP);

		sleep(3); /* pause for 3 secs */
		printf("\nPARENT: sending SIGINT\n\n");
		kill(pid, SIGINT);

		sleep(3); /* pause for 3 secs */
		printf("\nPARENT: sending SIGQUIT\n\n");
		kill(pid, SIGQUIT);
		sleep(3);
	}
}

// sighup() function definition
void sighup()

{
	signal(SIGHUP, sighup); /* reset signal */
	printf("CHILD: I have received a SIGHUP\n");
}

// sigint() function definition
void sigint()

{
	signal(SIGINT, sigint); /* reset signal */
	printf("CHILD: I have received a SIGINT\n");
}

// sigquit() function definition
void sigquit()
{
	printf("My DADDY has Killed me!!!\n");
	exit(0);
}