ex1 w5 p1

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

#define MAX_MESSAGE_SIZE 1024

int main() {
    int pipe_fd[2];
    pid_t child_pid;

    // Create the pipe
    if (pipe(pipe_fd) == -1) {
        perror("Pipe creation failed");
        exit(EXIT_FAILURE);
    }

    // Fork a child process
    if ((child_pid = fork()) == -1) {
        perror("Fork failed");
        exit(EXIT_FAILURE);
    }

    if (child_pid == 0) {
        // Child process (Subscriber)
        close(pipe_fd[1]); // Close the write end of the pipe (not needed by subscriber)

        char message[MAX_MESSAGE_SIZE];
        ssize_t bytes_read;

        while ((bytes_read = read(pipe_fd[0], message, MAX_MESSAGE_SIZE)) > 0) {
            // Print the message received from the publisher
            write(STDOUT_FILENO, message, bytes_read);
        }

        close(pipe_fd[0]); // Close the read end of the pipe
    } else {
        // Parent process (Publisher)
        close(pipe_fd[0]); // Close the read end of the pipe (not needed by publisher)

        char message[MAX_MESSAGE_SIZE];
        ssize_t bytes_read;

        while ((bytes_read = read(STDIN_FILENO, message, MAX_MESSAGE_SIZE)) > 0) {
            // Send the message to the subscriber via the pipe
            write(pipe_fd[1], message, bytes_read);
        }

        close(pipe_fd[1]); // Close the write end of the pipe
    }

    return 0;
}