Q1:

https://d2vlcm61l7u1fs.cloudfront.net/media%2Fcee%2Fceea072b-0857-447b-b62b-92acb2f7d0f4%2FphpWaABFp.png

https://d2vlcm61l7u1fs.cloudfront.net/media%2F0ad%2F0adf5ffc-2f7f-4d0e-99c8-dff08e34a4b3%2FphpZnX2VB.png

Q2:

https://d2vlcm61l7u1fs.cloudfront.net/media%2F91b%2F91b8b33d-feb1-4029-8b5a-7d3505f664f6%2Fphpv4ZL0I.png

https://d2vlcm61l7u1fs.cloudfront.net/media%2F9ed%2F9ed61264-5b6a-4d70-a676-1271c5bdf4b9%2FphpYfCUEN.png

Q3:

The process sleeps for 5 seconds after receiving each signal.

Here is the working code:

#include <stdio.h>
#include <sys/types.h>
#include <signal.h>
#include <sys/ipc.h>
#include <sys/shm.h>
// #include <signal.h>
#include <stdlib.h>
#include <unistd.h>


void sighup(int); /* routines child will call upon sigtrap */
void sigint(int);
void sigquit(int);
void main(void)
{
    signal(SIGHUP,sighup); /* set function calls */
    signal(SIGINT,sigint);
    signal(SIGQUIT, sigquit);

    int pid;
     if ((pid = fork()) < 0) {
        perror("fork");
        exit(1);
    }
     if(pid==0){

          for(;;); /* loop for ever */
     }
    else {
        signal(SIGHUP, SIG_DFL);
        signal(SIGINT, SIG_DFL);
        signal(SIGQUIT, SIG_DFL);

        /* parent */
        /* pid hold id of child */
        printf("\nPARENT: sending SIGHUP\n\n");
        kill(pid,SIGHUP);
        sleep(5); /* pause for 5 secs */
        printf("\nPARENT: sending SIGINT\n\n");
        kill(pid,SIGINT);
        sleep(5); /* pause for 5 secs */
        printf("\nPARENT: sending SIGQUIT\n\n");
        kill(pid,SIGQUIT);
        sleep(5);
    }
}
void sighup(int signo) {
    signal(SIGHUP,sighup); /* reset signal */
    printf("CHILD: I have received a SIGHUP\n");
}

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

void sigquit(int signo) {
    printf("I have received SIGQUIT\n");
    exit(0);
}