GTK 程序 检测 网线是否连接 本地网络状态 C语言实现

思路:

主程序创建一个进程, 每2秒查看一下网络状态,然后打印输出

通过检查文件

/sys/class/net/wlan0/operstate (无线网络)

/sys/class/net/eth0/operstate (有线网络)

通过检查文件的内容 判断当前网络是否连接

值为up的时候,是连接 值为down的时候 是断开

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <gtk/gtk.h> 
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>

#define WIRELESS

#ifdef WIRELESS
#define INTERNET_STATUS_FILE "/sys/class/net/wlan0/operstate"
#else
#define INTERNET_STATUS_FILE "/sys/class/net/eth0/operstate"
#endif

#include <sys/wait.h>

static GtkWidget *fixed; 
static GtkWidget *button1; 
static GtkWidget *button2; 
int running = 1;

void ring()
{
	GtkWidget *window;
	GtkWidget *table;
	GtkWidget *button_cancel;
	GtkWidget *label;

	window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
	gtk_window_set_default_size (GTK_WINDOW(window),100,100);
	gtk_window_set_position (GTK_WINDOW(window),GTK_WIN_POS_CENTER_ALWAYS);
	table = gtk_table_new(10,10,TRUE);
	gtk_container_add (GTK_CONTAINER (window),table);
	label = gtk_label_new("ring");
	button_cancel = gtk_button_new_with_label ("quit");
	gtk_table_attach_defaults (GTK_TABLE(table),button_cancel,2,4,7,9);

	gtk_widget_show_all(window);

}

void www_connect_check_real ()
{
	int ret = -2;
	while (1)
	{
		//一定要只读模式打开,读写模式打开不可以
		ret = open ("/sys/class/net/wlan0/operstate",O_RDONLY);

		if (ret<0) {
		printf("open file operstate failure%d\n",ret);
		return;
		}
		char status[3]="wl\0";
		//printf("%s",status);
		read (ret,status,2);
		status[3] = '\0';
		if (0== strcmp("up",status))
		{
			printf("on line now \n");
		}
		else if (0== strcmp("do",status))
		{
			printf("off off \n");
		}
		else 
		printf("unknow error\n");
		close (ret);

		sleep (5);
	}
	
}

int main(int argc,char* argv[]) 
{ 
	GtkWidget *window,*view; 
	GtkWidget *vbox,*button,*label;

	/*线程初始化*/
	if (!g_thread_supported()) 
	g_thread_init(NULL); 

	gdk_threads_init();

	gtk_init(&argc,&argv); 
	window=gtk_window_new(GTK_WINDOW_TOPLEVEL); 
	gtk_window_set_title(GTK_WINDOW(window),"thread apllication"); 

	

	vbox=gtk_vbox_new(FALSE,0); 
	gtk_container_add(GTK_CONTAINER(window),vbox); 

	label=gtk_label_new("Notice! Button is moving"); 
	gtk_box_pack_start(GTK_BOX(vbox),label,FALSE,FALSE,0); 
	view=gtk_viewport_new(NULL,NULL); 
	gtk_box_pack_start(GTK_BOX(vbox),view,FALSE,FALSE,0); 
	fixed=gtk_fixed_new(); 
	gtk_widget_set_usize(fixed,330,330); 
	gtk_container_add(GTK_CONTAINER(view),fixed); 
	button1=gtk_button_new_with_label("1"); 
	button2=gtk_button_new_with_label("2"); 
	gtk_fixed_put(GTK_FIXED(fixed),button1,10,10); 
	gtk_fixed_put(GTK_FIXED(fixed),button2,40,40); 

	GtkWidget *button_ring = gtk_button_new_with_label ("ring");
	gtk_box_pack_start(GTK_BOX(vbox),button_ring,FALSE,FALSE,5); 
	g_signal_connect (button_ring,"clicked",G_CALLBACK(ring),NULL);

	/*创建线程*/
	g_thread_create((GThreadFunc)www_connect_check_real,NULL,FALSE,NULL); 	
	

	

	gtk_widget_show_all(window); 
	g_signal_connect(G_OBJECT(window),"delete_event",G_CALLBACK(gtk_main_quit),NULL); 
	gtk_container_set_border_width(GTK_CONTAINER(window),10); 	
	gdk_threads_enter(); 
	gtk_main(); 
	gdk_threads_leave(); 

	return FALSE; 
}

注意:

1,ubuntu 10.04上,当使用静态IP的时候,即使 连接着网络, 文件的值也不up 而是unknown, 这是驱动上的bug,ubuntu 11.10上就正常

http://docs.redhat.com/docs/en-US/Red_Hat_Enterprise_Linux/5/html/5.7_Technical_Notes/kernel.html

2,相关链接

http://stackoverflow.com/questions/808560/how-to-detect-the-physical-connected-state-of-a-network-cable-connector

http://www.linuxforums.org/forum/programming-scripting/142431-how-write-program-c-detect-ethernet-cable.html

3,也可以使用shell脚本来检测,网上例子很多

4,也可以编写一个内核模块来检测,后期再说,先找工作

http://stackoverflow.com/questions/7225888/how-can-i-monitor-the-nic-statusup-down-in-a-c-program-without-polling-the-ker

5,

//RFC 2863操作状态
	unsigned char		operstate;
	/* operstate的可能取值如下：
	enum {
		IF_OPER_UNKNOWN,
		IF_OPER_NOTPRESENT,
		IF_OPER_DOWN,
		IF_OPER_LOWERLAYERDOWN,
		IF_OPER_TESTING,
		IF_OPER_DORMANT,
		IF_OPER_UP,
	};
	 **/ 
	//映射到RFC2863兼容状态的策略
	unsigned char		link_mode;
	/* link_mode的可能取值如下：
	enum {
		IF_LINK_MODE_DEFAULT,
		IF_LINK_MODE_DORMANT,
	};
	 **/

我们检测的文件内容,其实是这个成员变变量的值,返回值比较多,程序中只是判断了前两个字符

http://blog.csdn.net/npy_lp/article/details/7056903