Grabs data from a zmq socket and sends it to STDOUT

zmq_to_pipe.c

// gcc -o zmq_to_pipe zmq_to_pipe.c -lzmq
#include <stdio.h>
#include <stdlib.h>
#include <zmq.h>

int main(int argc, char *argv[]) {
    if (argc != 2) {
        fprintf(stderr, "Usage: %s <zmq_socket_path>\n", argv[0]);
        return 1;
    }

    void *context = zmq_ctx_new();
    void *socket = zmq_socket(context, ZMQ_SUB);

    if (zmq_connect(socket, argv[1]) != 0) {
        fprintf(stderr, "Failed to connect to ZMQ socket: %s\n", argv[1]);
        zmq_ctx_destroy(context);
        return 1;
    }

    zmq_setsockopt(socket, ZMQ_SUBSCRIBE, "", 0);

    while (1) {
        zmq_msg_t message;
        zmq_msg_init(&message);
        int size = zmq_msg_recv(&message, socket, 0);
        if (size == -1) {
            fprintf(stderr, "Error receiving from ZMQ socket: %s\n", zmq_strerror(zmq_errno()));
            zmq_msg_close(&message);
            break;
        }

        fwrite(zmq_msg_data(&message), 1, size, stdout);
        fflush(stdout);

        zmq_msg_close(&message);
    }

    zmq_close(socket);
    zmq_ctx_destroy(context);
    return 0;
}