SO_LAB9_grA

#include <stdio.h>
#include <unistd.h>
#include <sys/stat.h>

#define FIFO "sync"
#define RESULT "result.txt"
#define READ 0
#define WRITE 1

int silnia(int x)
{
    if (x <= 1)
        return 1;

    return x * silnia(x - 1);
}

int main()
{
    printf("Dopisywac do pliku? y/n: ");
    int c = getchar();

    int pipedes[2];
    pipe(pipedes);

    umask(0);
    mkfifo(FIFO, 0666);

    if (!fork())
    {
        close(pipedes[WRITE]);

        while (1)
        {
            int x;
            read(pipedes[READ], &x, sizeof(x));

            int result = silnia(x);

            FILE *f = fopen(FIFO, "w");
            fprintf(f, "%d", result);
            fclose(f);
        }
    }

    if (!fork())
    {
        while (1)
        {
            int x;
            FILE *fifo = fopen(FIFO, "r");
            fscanf(fifo, "%d", &x);
            fclose(fifo);

            printf("Wynik: %d\n", x);

            if (c == 'y') {
                FILE *f = fopen(RESULT, "a");
                fprintf(f, "%d\n", x);
                fclose(f);
            }
        }
    }

    close(pipedes[READ]);

    while (1)
    {
        int x;
        scanf("%d", &x);
        write(pipedes[WRITE], &x, sizeof(x));
    }
}