subscriber.c

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <string.h>

#define MAX_MESSAGE_SIZE 1024

int main(int argc, char* argv[]) {
    if (argc != 2) {
        fprintf(stderr, "Usage: %s <subscriber_id>\n", argv[0]);
        exit(EXIT_FAILURE);
    }

    int subscriber_id = atoi(argv[1]);
    char fifo_path[20];
    snprintf(fifo_path, sizeof(fifo_path), "/tmp/ex1/s%d", subscriber_id);

    int pipe_fd = open(fifo_path, O_RDONLY);
    if (pipe_fd == -1) {
        perror("Failed to open named pipe");
        exit(EXIT_FAILURE);
    }

    char message[MAX_MESSAGE_SIZE];
    ssize_t bytes_read;

    while ((bytes_read = read(pipe_fd, message, MAX_MESSAGE_SIZE)) > 0) {
        write(STDOUT_FILENO, message, bytes_read);
    }

    close(pipe_fd);

    return 0;
}