#include <stdio.h>
#include <signal.h>
#include <fcntl.h>
#include <stdlib.h>
int fd, pid1, pid2, pid3;
FILE *file;
char arr[20];
int N = 10;
int finishedCount = 0;


void process1_write(int signum)
{
    printf ("Child 1 write to file, pid = %d\n", getpid());
    for (int i = 0; i < N; ++i)
    {
        printf("c1: %d\n", write(fd, "A", 1));
    }
    printf("Child 1 finished\n" );
    kill(pid1, SIGUSR1);
}


void process2_write(int signum)
{
    printf ("Child 2 write to file, pid = %d\n", getpid());
    for (int i = 0; i < N; ++i)
    {
        printf("c2: %d\n", write(fd, "B", 1));
    }
    printf("Child 2 finished\n" );
    kill(pid1, SIGUSR1);
}

void process_main_result(int signum)
{
        finishedCount++;
        printf("Finished:  %d \n",finishedCount);

    if (finishedCount == 2)
    {
        file = fopen("res.txt", "r");
        fgets(arr, N*3, file);
        printf("Result:  %s \n",arr);
        kill(pid2, SIGKILL);
        kill(pid3, SIGKILL);
        kill(pid1, SIGKILL);
    }
}


int main()
{

    pid1 = getpid();
    fd = open("res.txt", O_CREAT | O_RDWR | O_TRUNC, 0666);
    printf("Введите количество байт:\n");
    scanf("%d",&N);

    signal(SIGUSR1, process1_write);

    pid2 = fork();
    if (pid2 != 0)
    {
        pid3 = fork();
    }
    if (pid2 == 0)
    {

        printf ("Child 1, pid = %d\n", getpid());

        signal(SIGUSR1, process1_write);
        for(;;);
    }
    else if (pid3 == 0)
    {

        printf ("Child 2, pid = %d\n", getpid());

        signal(SIGUSR1, process2_write);
        for(;;);
    }
    else
    {
        signal(SIGUSR1, process_main_result);
        sleep(5);
        kill(pid2, SIGUSR1);
        sleep(5);
        kill(pid3, SIGUSR1);
        for(;;);
    }


 }