char firstInput[MAX_LINE];
char endMsg = EOT;
int pipes[4][2], i, pid;
ssize_t byteSent;

for(i=0; i<4; i++)
{
    if(pipe(pipes[i]) < 0)
    {
        printf("couldnt make pipe..");
    }
}

scanf("%s", firstInput);
pid=fork(); //Writer process starts
if(pid==(pid_t)0)
{
    //inside Writer process:

    close(pipes[READER32_P][INPUT]);
    close(pipes[READER32_P][OUTPUT]);
    close(pipes[READER64_p][INPUT]);
    close(pipes[READER64_p][OUTPUT]);
    close(pipes[READERS_P][INPUT]);
    close(pipes[READERS_P][OUTPUT]);
    close(pipes[WRITER_P][OUTPUT]);

    Writer(pipes, firstInput);
    exit(EXIT_SUCCESS);
}
else
{
    pid=fork();
    if(pid==(pid_t)0)  //Reader32 process starts
    {
        //inside Reader32 process:

        close(pipes[WRITER_P][INPUT]);
        close(pipes[WRITER_P][OUTPUT]);
        close(pipes[READER64_p][INPUT]);
        close(pipes[READER64_p][OUTPUT]);
        close(pipes[READERS_P][INPUT]);
        close(pipes[READER32_P][OUTPUT]);

        Reader32(pipes);
        exit(EXIT_SUCCESS);
    }
    else
    {

        pid=fork(); //Reader64 process starts
        if(pid == (pid_t)0)
        {
            //inside Reader64:

            close(pipes[WRITER_P][INPUT]);
            close(pipes[WRITER_P][OUTPUT]);
            close(pipes[READER32_P][INPUT]);
            close(pipes[READER32_P][OUTPUT]);
            close(pipes[READERS_P][INPUT]);
            close(pipes[READER64_p][OUTPUT]);


            Reader64(pipes);
            exit(EXIT_SUCCESS);
        }
        else
        {
            //main process:

            close(pipes[WRITER_P][INPUT]);
            close(pipes[READER32_P][INPUT]);
            close(pipes[READER64_p][INPUT]);
            close(pipes[READERS_P][OUTPUT]);

            char msg = OK;
            int lastInput = 0;
            int polyType;
            unsigned long long polygon;
            while(!lastInput)
            {
                polygon = 0;
                scanf("%d", &polyType);
                if(polyType==32)
                {
                    write(pipes[READER32_P][OUTPUT], &msg, sizeof(char));
                }
                else if(polyType==64)
                {
                    byteSent = write(pipes[READER64_p][OUTPUT], &msg, sizeof(char));
                    printf("sent %zd bytes from main_process to reader64n msg sent is %cn", byteSent, msg);
                }
                wait(NULL);
                read(pipes[READERS_P][INPUT], &polygon, sizeof(unsigned long long int));
                if((polygon & 1) > 0)
                    lastInput=1;
                write(pipes[WRITER_P][OUTPUT], &polygon, sizeof(unsigned long long int));
            }
            //sending ending msgs to all child processes:

            write(pipes[WRITER_P][OUTPUT], &endMsg, sizeof(char));
            write(pipes[READER32_P][OUTPUT], &endMsg, sizeof(char));
            write(pipes[READER64_p][OUTPUT], &endMsg, sizeof(char));

            //closing left pipes:

            close(pipes[WRITER_P][OUTPUT]);
            close(pipes[READER32_P][OUTPUT]);
            close(pipes[READER64_p][OUTPUT]);
            close(pipes[READERS_P][INPUT]);

            //finishing the process:

            printf("main_process pid=%d is going to exit",getpid());
            return 0;
        }
    }
}

printf("Reader32 started...n");
unsigned int endMsgRcvd=0;
ssize_t byteSent;
char reader32Buffer[MAX_LINE];
unsigned long long int polygon32;
unsigned long long int temp32;
while(!endMsgRcvd)
{
    byteSent = read(pipes[READER32_P][INPUT],reader32Buffer,MAX_LINE);
    if(reader32Buffer[0] == EOT)
    {
        endMsgRcvd = 1;
        break;
    }
    else
    {
        polygon32 = 0;
        temp32 = 0;
        scanf("%llx", &polygon32);
        scanf("%llx", &temp32);
        temp32 <<= 32;
        polygon32 |= temp32;
        write(pipes[READERS_P][OUTPUT], &polygon32, sizeof(unsigned long long));
    }
}
close(pipes[READER32_P][INPUT]);
close(pipes[READERS_P][OUTPUT]);
fprintf(stderr, "reader32 pid=%d is going to exit...", getpid());

printf("Reader32 started...n");
unsigned int endMsgRcvd=0;
ssize_t byteSent;
char reader32Buffer[MAX_LINE];
unsigned long long int polygon32;
unsigned long long int temp32;
while(!endMsgRcvd)
{
    byteSent = read(pipes[READER32_P][INPUT],reader32Buffer,MAX_LINE);
    if(reader32Buffer[0] == EOT)
    {
        endMsgRcvd = 1;
        break;
    }
    else
    {
        polygon32 = 0;
        temp32 = 0;
        scanf("%llx", &polygon32);
        scanf("%llx", &temp32);
        temp32 <<= 32;
        polygon32 |= temp32;
        write(pipes[READERS_P][OUTPUT], &polygon32, sizeof(unsigned long long));
    }
}
close(pipes[READER32_P][INPUT]);
close(pipes[READERS_P][OUTPUT]);
fprintf(stderr, "reader32 pid=%d is going to exit...", getpid());