parentChildSync.c

/******************
author : bsm
description: synhronization between parent and child process
***************/

#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>

int main()
{
    pid_t pid;
    char *message;
    int n, exit_code;

    printf("starting fork process\n");
    pid = fork();
    switch(pid) 
    {
    case -1:
        perror("fork process failed");
        exit(1);
    case 0:
        message = "This is the child process";
        n = 5;
	exit_code = 37;
        break;
    default:
        message = "This is the parent process";
        n = 3;
	exit_code = 0;
        break;
    }

    for(; n > 0; n--) {
        puts(message);
        sleep(1);
    }

if (pid != 0) {
	int stat_val;
	pid_t child_pid;
	child_pid = wait(&stat_val);
	printf("Child has finished: PID = %d\n", child_pid);

	if(WIFEXITED(stat_val))
		printf("Child exited with code %d\n", WEXITSTATUS(stat_val));
	else
		printf("Child terminated abnormally\n");
}

exit(exit_code);
}