dbus_listen_recv.c

gistfile1.txt

#include <stdio.h>
#include <dbus/dbus.h>
#include <stdlib.h>
#include <unistd.h>

void send_signal(DBusConnection *conn) {
    DBusMessage *msg;
    DBusMessageIter args;

    msg = dbus_message_new_signal("/com/example/TestObject", // object name
                                  "com.example.TestSignal.Type", // interface name
                                  "Test"); // name of the signal
    if (NULL == msg) {
        fprintf(stderr, "Message Null\n");
        exit(1);
    }

    dbus_connection_send(conn, msg, NULL);
    dbus_connection_flush(conn);
    printf("Signal Sent!\n");

    dbus_message_unref(msg);
}

void receive_signal(DBusConnection *conn) {
    dbus_bus_add_match(conn, "type='signal',interface='com.example.TestSignal.Type'", NULL);
    dbus_connection_flush(conn);

    while (1) {
        dbus_connection_read_write(conn, 0);
        DBusMessage *msg = dbus_connection_pop_message(conn);

        if (msg == NULL) {
            sleep(1);
            continue;
        }

        if (dbus_message_is_signal(msg, "com.example.TestSignal.Type", "Test")) {
            printf("Received signal!\n");
        }

        dbus_message_unref(msg);
    }
}

int main() {
    DBusError err;
    DBusConnection *conn;

    dbus_error_init(&err);

    conn = dbus_bus_get(DBUS_BUS_SESSION, &err);
    if (dbus_error_is_set(&err)) {
        fprintf(stderr, "Connection Error: %s\n", err.message);
        dbus_error_free(&err);
        return 1;
    }

    send_signal(conn);
    receive_signal(conn);

    return 0;
}