receiver.c

#include <assert.h>
#include <zmq.h>

int main(int argc, char *argv[]) {
    void *ctx = zmq_init(1);
    assert(ctx);
    void *sock = zmq_socket(ctx, ZMQ_PULL);
    assert(sock);
    int rc = zmq_connect(sock, "tcp://127.0.0.1:5555");
    assert (rc == 0);
    while(1) {
        zmq_msg_t msg;
        zmq_msg_init(&msg);
        rc = zmq_recv(sock, &msg, 0);
        assert(rc == 0);
        printf("MESSAGE ``%.*s''\n", (int)zmq_msg_size(&msg), zmq_msg_data(&msg));
    }
    rc = zmq_close(sock);
    assert (rc == 0);
    rc = zmq_term(ctx);
    assert (rc == 0);
}

sender.c

#include <assert.h>
#include <xs.h>

int main(int argc, char *argv[]) {
    void *ctx = xs_init();
    assert(ctx);
    void *sock = xs_socket(ctx, XS_PUSH);
    assert(sock);
    int rc = xs_bind(sock, "tcp://127.0.0.1:5555");
    assert(rc == 0);
    do {
        rc = xs_send(sock, "ABC", 3, XS_SNDMORE);
        assert(rc == 0 || errno == EAGAIN);
    } while(rc != 0);
    assert (rc == 0);
    rc = xs_send(sock, "def", 3, 0);
    assert (rc == 0);
    rc = xs_close(sock);
    assert (rc == 0);
    rc = xs_term(ctx);
    assert (rc == 0);
}