#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include <fcntl.h>
#define PERMS 0666

void exitt(int sgc){
    exit(1);
}

int main () {
    int pid2, pid3, pid4, pid5, pid6, st;

//parent
    printf("main parent process %d\n",getpid());
    pid2 = fork();

//first child
    if (pid2 == 0) {
        int fd;
        char fname[10];
        sprintf(fname, "%d",getpid());
        if((fd, open(fname, O_CREAT | O_WRONLY, PERMS)) < 0 ){
            perror("open file error");
        }
            close(fd);
        printf("first child process%d\n",getpid());
        }
        pid3 = fork();

//second child
    if (pid3 == 0){
        int fd;
        char fname[10];
        sprintf(fname, "%d",getpid());
        if((fd, open(fname, O_CREAT | O_WRONLY, PERMS)) < 0 ){
            perror("open file error");
        }
            close(fd);
        printf("second child process%d\n", getpid());
        }
        pid4 = fork();

//third child
    if (pid4 == 0){
        int fd;
        char fname[10];
        sprintf(fname, "%d",getpid());
        if((fd, open(fname, O_CREAT | O_WRONLY, PERMS)) < 0 ){
            perror("open file error");
        }
            close(fd);
        printf("third child process%d\n",getpid());
        }
        pid5 = fork();

//fourth child
    if (pid5 == 0){
        int fd;
        char fname[10];
        sprintf(fname, "%d",getpid());
        if((fd, open(fname, O_CREAT | O_WRONLY, PERMS)) < 0 ){
            perror("open file error");
        }
            close(fd);
        printf("fourth child process%d\n",getpid());
        }
        pid6 = fork();
//fifth child
    if (pid6 == 0){
        int fd;
        char fname[10];
        sprintf(fname, "%d",getpid());
        if((fd, open(fname, O_CREAT | O_WRONLY, PERMS)) < 0 ){
            perror("open file error");
        }
            close(fd);
        printf("fifth child process%d\n",getpid());
        signal (SIGINT, exitt);

}
if ( pid6 < 0) {
printf("can't create process 6:error %d\n", pid6);
signal (SIGINT, exitt);
kill(pid2,SIGINT);

sleep(1);
}
else
if (pid5 < 0){
    printf("can't create process 5:error %d\n", pid5);
    signal (SIGINT, exitt);
    kill(pid5,SIGINT);
}
else
if (pid4 < 0){
    printf("can't create process 4:error %d\n", pid4);
    signal (SIGINT, exitt);
    kill(pid4,SIGINT);

}
else
if (pid3 < 0){
    printf("can't create process 3:error %d\n", pid3);
    signal (SIGINT, exitt);
    kill(pid3,SIGINT);

}
else
{
if (pid2 < 0)
    printf("can't create process 2:error %d\n", pid2);
    signal (SIGINT, exitt);
    kill(pid2,SIGINT);
}
wait(&st);
return 0;
}