Assignment 6 – C program Unix environment – three players game – System Programming

Extend example 11 from Chapter VI to the case of three players with the following changes:
 the winning total should be read from the keyboard before the game starts and before any
fork(for example 50 or 500).
 Your program should ignore CTR-C and CTR-Z signals
 The referee should be the one to check the scores and to declare the winner. A common
file should be used between processes for communicating their current score to the
referee.

Answer:

#include <stdio.h>
#include <sys/signal.h>
#include <sys/wait.h>
#include <unistd.h>

void action(){};
void child(char *);
int input;

int main(int argc, char *argv[]){
    int i=6, s, pid;
    pid_t pid1, pid2, pid3;

    FILE *fp; 


    void (*oldHandler1)();
    void (*oldHandler2)(); 
    oldHandler1=signal(SIGINT, SIG_IGN); 
    oldHandler2=signal(SIGTSTP, SIG_IGN);

    printf("\nProgram running...CTR-C and CTR-Z disabled...\n");
    
    printf("\nHello this is a 3-players game with a referee\n");
    printf("Please enter the winning total score below: ");
    scanf("%d",&input);
    
    if((pid1=fork()) == 0)
        child("TOTO");
    
    if((pid2=fork()) == 0)
        child("TITI");

    if((pid3=fork()) == 0)
        child("TSTS");
    
    sleep(1);
    while(1){
        printf("\nReferee: TOTO plays\n\n");
        kill(pid1, 16);
        signal(16, action);
        pause();
        
        printf("\n\nReferee: TITI plays\n\n");
        kill(pid2, 16);
        signal(16, action);
        pause();
        
        printf("\n\nReferee: TSTS plays\n\n");
        kill(pid3, 16);
        signal(16, action);
        pause();
        
    }
}

void child(char *s){
    int points=0;
    int dice;
    long int ss=0;
    
    while(1){
        signal(16, action);
        pause();
        printf("%s: playing my dice\n", s);
        dice =(int) time(&ss)%10 + 1;
        printf("%s: got %d points\n", s, dice);
        points+=dice;
        printf("%s: Total so far %d\n\n", s, points);
        sleep(2);
        if(points >= input){
            printf("%s: game over I won\n", s);
            kill(0, SIGTERM);
        }
        kill(getppid(), 16);
    }
}