#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <string.h>
#include <dirent.h>
#include <sys/types.h>
#include <sys/wait.h>

int main(int argc, char *argv[])
{
    int pfd[2];
    int pfd2[2];
    int pid;

    if(pipe(pfd)<0)
    {
        printf("Error creating the pipe");
        exit(1);
    }

    if(pipe(pfd2)<0)
    {
        printf("Error creating the pipe");
        exit(1);
    }

    if((pid=fork())<0)
    {
        printf("Error fork");
        exit(1);
    }

    if(pid>0)
    {

        int pid2;
        if((pid2=fork())<0)
        {
            printf("Error fork");
            exit(1);
        }
        if(pid2>0)
        {
            int pid3;
            if((pid3=fork())<0)
            {
                printf("Error fork");
                exit(1);
            }
            if(pid3>0){

            close(pfd2[0]);
            close(pfd[0]);
            char c;
            int n;
            int fd = open(argv[1], O_RDONLY);
            if (fd < 0)
            {
                printf("Error opening the file\n");
                exit(1);
            }

            while ((n = read(fd, &c, 1)) > 0)
            {
                int i = c - '0';
                if(i>=0&&i<=9)
                {
                    if(i%2!=0)
                    {
                        write(pfd2[1], &c, 1);
                    }
                    else
                    {
                        write(pfd[1], &c, 1);
                    }
                }
            }

            close(pfd2[1]);
            close(pfd[1]);


            int status;
            if ( waitpid(pid, &status, 0) == -1 ) {
             perror("waitpid failed");
             return EXIT_FAILURE;
            }

            if ( WIFEXITED(status) ) {
                const int es = WEXITSTATUS(status);
                printf("Exit status for %d(odd digits): %d\n", pid, es);
            }

            if ( waitpid(pid2, &status, 0) == -1 ) {
             perror("waitpid failed");
             return EXIT_FAILURE;
            }

            if ( WIFEXITED(status) ) {
                const int es = WEXITSTATUS(status);
                printf("Exit status for %d(even digits): %d\n", pid2, es);
            }

            exit(0);
            }
            else
            {
                char * const ptr[]={"/bin/sh","-c","ls -l" ,NULL};
                execv("/bin/sh",ptr);
                exit(0);
            }

        }
        else
        {
            close(pfd[1]);
            close(pfd2[1]);
            close(pfd2[0]);

            char c;
            int t, evenCount=0;

            while((t = read(pfd[0], &c, 1)) > 0)
            {
                evenCount++;
            }

            //printf("%d even digit(s)\n", evenCount);

            close(pfd[0]);
            exit(evenCount);
        }


    }
    else
    {
        close(pfd2[1]);
        close(pfd[1]);
        close(pfd[0]);

        char c;
        int r, count=0;

        while((r = read(pfd2[0], &c, 1))>0)
        {
            count++;
        }

        //printf("%d odd digit(s)\n", count);

        close(pfd2[0]);
        exit(count);
    }
}