1.server.c

#include <stdio.h>
#include <string.h>
#include <dbus/dbus.h>

int main()
{
    DBusConnection *connection = NULL;
    DBusError error;

    dbus_error_init(&error);

    connection = dbus_bus_get(DBUS_BUS_SESSION, &error);

    if(dbus_error_is_set(&error))
    {
        printf("连接DBUS失败: %s\n", error.message);

        dbus_error_free(&error);

        return 1;
    }

    printf("等待客户端请求...\n");

    int ret = dbus_bus_request_name(connection, "com.example.TestServer", DBUS_NAME_FLAG_REPLACE_EXISTING, &error);

    if(dbus_error_is_set(&error))
    {
        printf("注册DBUS服务失败: %s\n", error.message);

        dbus_error_free(&error);

        return 1;
    }

    while(1)
    {
        dbus_connection_read_write_dispatch(connection, -1);

        DBusMessage *message = NULL;

        message = dbus_connection_pop_message(connection);

        if(message == NULL)
        {
            sleep(1);

            continue;
        }

        if(dbus_message_is_method_call(message, "com.example.TestInterface", "Hello"))
        {
            DBusMessage *reply;
            const char *reply_str = "Hello, Client!";

            reply = dbus_message_new_method_return(message);

            dbus_message_append_args(reply, DBUS_TYPE_STRING, &reply_str, DBUS_TYPE_INVALID);

            dbus_connection_send(connection, reply, NULL);

            dbus_message_unref(reply);
        }

        dbus_message_unref(message);
    }

    return 0;
}

2,client.c

#include <stdio.h>
#include <string.h>
#include <dbus/dbus.h>

int main()
{
    DBusConnection *connection = NULL;
    DBusError error;

    dbus_error_init(&error);

    connection = dbus_bus_get(DBUS_BUS_SESSION, &error);

    if(dbus_error_is_set(&error))
    {
        printf("连接DBUS失败: %s\n", error.message);

        dbus_error_free(&error);

        return 1;
    }

    const char *server_name = "com.example.TestServer";
    DBusMessage *message = NULL;

    message = dbus_message_new_method_call(server_name, "/com/example/TestObject", "com.example.TestInterface", "Hello");

    DBusPendingCall *pending;

    dbus_connection_send_with_reply(connection, message, &pending, -1);

    //dbus_pending_call_set_timeout(pending, 1000);
    dbus_pending_call_block(pending);

    DBusMessage *reply;

    if(dbus_pending_call_get_completed(pending))
    {
        reply = dbus_pending_call_steal_reply(pending);

        char *str_result;

        dbus_message_get_args(reply, NULL, DBUS_TYPE_STRING, &str_result, DBUS_TYPE_INVALID);

        printf("接收到来自Server的回复：%s\n", str_result);

        dbus_message_unref(reply);
    }

    dbus_pending_call_unref(pending);
    dbus_message_unref(message);

    return 0;
}

3.编译源码

$ gcc -g -o server server.c -I/usr/include/dbus-1.0 -I/usr/lib64/dbus-1.0/include -ldbus-1
$ gcc -g -o client client.c -I/usr/include/dbus-1.0 -I/usr/lib64/dbus-1.0/include -ldbus-1

4.运行及其结果

$ ./server
$ ./client
接收到来自Server的回复：Hello, Client!