Glib簡介

Glib庫是C語言的好夥伴,整體設計的非常好!
但是,Glib的例子非常少. 不容易學習和借鑑.
這裡的例子就是採用glib的高層網路API實現的TCP服務端和客戶端.

以下例項都是正常執行的程式碼

TCP服務端程式碼例項:

#include <glib.h>
#include <gio/gio.h>

gchar *buffer;

gboolean
network_read(GIOChannel *source,
            GIOCondition cond,
            gpointer data)
{
  GString *s
 
 = g_string_new(NULL);
    //error should be inited with NULL
  GError *error=NULL;
  GIOStatus ret = g_io_channel_read_line_string(source, s, NULL, &error);
  if (ret == G_IO_STATUS_ERROR){
    g_error ("Error reading: %s\n", error->message);
    g_object_unref(data);
    return FALSE;
    }
  else
 
 if (ret == G_IO_STATUS_EOF){
        g_print("finished\n");
        return FALSE;
    }else{
    g_print("Got: %s\n", s->str);

    //you should return this
    return TRUE;
    }

}

gboolean
new_connection(GSocketService *service,
              GSocketConnection *connection,
              GObject *source_object
 
,
              gpointer user_data)
{
    // tell glib not to disconnect
    g_object_ref(connection);
  GSocketAddress *sockaddr = g_socket_connection_get_remote_address(connection, NULL);
  GInetAddress *addr = g_inet_socket_address_get_address(G_INET_SOCKET_ADDRESS(sockaddr));
  guint16 port = g_inet_socket_address_get_port(G_INET_SOCKET_ADDRESS(sockaddr));

  g_print("New Connection from %s:%d\n", g_inet_address_to_string(addr), port);

  GSocket *socket = g_socket_connection_get_socket(connection);

  gint fd = g_socket_get_fd(socket);
  GIOChannel *channel = g_io_channel_unix_new(fd);
  //g_io_add_watch(channel, G_IO_IN, (GIOFunc) network_read, NULL);
  g_io_add_watch(channel, G_IO_IN, (GIOFunc) network_read, connection);
  return TRUE;
}

int main(int argc, char **argv) {
  GSocketService *service = g_socket_service_new();
  GInetAddress *address = g_inet_address_new_from_string("127.0.0.1");
  GSocketAddress *socket_address = g_inet_socket_address_new(address, 4000);
  g_socket_listener_add_address(G_SOCKET_LISTENER(service), socket_address, G_SOCKET_TYPE_STREAM,
          G_SOCKET_PROTOCOL_TCP, NULL, NULL, NULL);

  g_object_unref(socket_address);
  g_object_unref(address);
  g_socket_service_start(service);

  g_signal_connect(service, "incoming", G_CALLBACK(new_connection), NULL);

  GMainLoop *loop = g_main_loop_new(NULL, FALSE);
  g_main_loop_run(loop);
}

TCP客戶端程式碼例項:

#include <glib.h>
#include <gio/gio.h>
#include <stdio.h>
#include <string.h>

int main(int argc, char *argv[])
{

    GError *error = NULL;

    GSocketClient * client = g_socket_client_new();

    //GSocketConnection * connection = g_socket_client_connect_to_host (client,"10.9.27.15",5000,NULL,&error);
    GSocketConnection * connection = g_socket_client_connect_to_host (client,"localhost",9100,NULL,&error);


    if (error){
        g_error(error->message);
    }else{
        g_message("Connection ok");
    }

    guint8 buffer[]={170, 255, 255, 1, 204, 125, 128};
    guint8 incoming_buff[100]={0};

    GInputStream * in_stream = g_io_stream_get_input_stream(G_IO_STREAM(connection));
    GOutputStream * out_stream = g_io_stream_get_output_stream(G_IO_STREAM(connection));
    g_output_stream_write(out_stream, buffer, 7, NULL, &error);
    int incoming_num = g_input_stream_read(in_stream,incoming_buff,100,NULL,&error);

    if(error)
        g_error(error->message);
    else{
        int i=0; 
        printf("incoming:\n");
        for(;i<incoming_num;i++)
            printf("%hhX ",incoming_buff[i]);
        printf("\n");

        //g_message(incoming_buff);
    }

    return TRUE;

}