lab8 zad1

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

double frac(double x) {
    if(x == 0)
        return 1;
    else if (x == 1)
        return 1;
    else
        return x*frac(x-1);
}

int main() {
    int fd[2];
    char str[100], wynik[100];;

    pipe(fd);

    if(fork() > 0) {
        double X;
        double Eps;

        close(fd[0]);

        printf("X = ");
        scanf("%lf", &X);
        sprintf(str, "%lf", X);
        write(fd[1], str, 101);

        printf("Eps = ");
        scanf("%lf", &Eps);
        sprintf(str, "%lf", Eps);
        write(fd[1], str, 101);

        close(fd[1]);
        sleep(1);
    }
    else {

        close(fd[1]);

        double X, Eps;

        read(fd[0], wynik, 101);
        X = strtod(wynik, NULL);

        read(fd[0], wynik, 101);
        Eps = strtod(wynik, NULL);

        close(fd[0]);

        int fd1[2];
        pipe(fd1);

        if(fork() > 0) {

            double i = 0;
            double fragment;

            do {
                fragment = pow(X, i)/frac(i);
                i++;
                sprintf(str, "%lf", fragment);
                write(fd1[1], str, 101);
                printf("%lf\n ", fragment);
            }
            while(fragment >= Eps);

            return 0;
        }
        else {
            double sum=0, tmp;
            close(fd1[1]);

            while(read(fd1[0], wynik, 101)>0) {
                tmp = strtod(wynik, NULL);
                sum += tmp;
            }

            printf("Suma: %f\n", sum);
            printf("Wynik = %f\n", exp(X));
            return 0;
        }
    }
    return 0;
}