Linux下获取USB设备插拔状态的通知

最近遇到一个需求，要求浏览器的内嵌keyboard与USB keyboard状态同步。

主要就是几个特殊的功能键，shift、alt、ctrl、caps、tab等等，借鉴了一个博客：http://www.voidcn.com/article/p-sjjkjzze-cy.html，其中提供了一段获取USB设备的代码，自己运行过后，有一定的帮助，具体的还需要深究。代码如下：

#include 
#include  
#include  
#include  
#include  
#include  
#include  
#include  
#include  
#include  
#include  
#include  
#include  

#define UEVENT_BUFFER_SIZE 2048 

static int init_hotplug_sock() {     
	
	const int buffersize = 1024;     
	int ret;     
	struct sockaddr_nl snl;     
	bzero(&snl, sizeof(struct sockaddr_nl));     

	snl.nl_family = AF_NETLINK;
	snl.nl_pid = getpid();
	snl.nl_groups = 1;

	int s = socket(PF_NETLINK, SOCK_DGRAM, NETLINK_KOBJECT_UEVENT);
	if (s == -1) {         
		perror("socket");
		return -1;
	}

	setsockopt(s, SOL_SOCKET, SO_RCVBUF, &buffersize, sizeof(buffersize));     
	ret = bind(s, (struct sockaddr *)&snl, sizeof(struct sockaddr_nl));     
	if (ret < 0) {         
		perror("bind");         
		close(s);        
		return -1;     
	}     

	return s; 
}


int main(int argc, char* argv[]) {
	int hotplug_sock = init_hotplug_sock();     

	while(1) {         
		/* Netlink message buffer */         
		char buf[UEVENT_BUFFER_SIZE * 2] = {0};         
		recv(hotplug_sock, &buf, sizeof(buf), 0); printf("%s\n", buf);         
		/* USB 设备的插拔会出现字符信息，通过比较不同的信息确定特定设备的插拔，在这添加比较代码 */     
	}

	return 0; 
}

编译之后，运行的结果如下：

add@/devices/platform/xxxxx-ehci-1.0/usb2/2-1
add@/devices/platform/xxxxx-ehci-1.0/usb2/2-1/2-1:1.0
add@/devices/platform/xxxxx-ehci-1.0/usb2/2-1/2-1:1.0/0003:046D:C31C.0006
add@/devices/platform/xxxxx-ehci-1.0/usb2/2-1/2-1:1.0/input/input6
add@/devices/platform/xxxxx-ehci-1.0/usb2/2-1/2-1:1.0/input/input6/event1
add@/devices/platform/xxxxx-ehci-1.0/usb2/2-1/2-1:1.0/0003:046D:C31C.0006/hidraw/hidraw0
add@/devices/platform/xxxxx-ehci-1.0/usb2/2-1/2-1:1.1
add@/devices/platform/xxxxx-ehci-1.0/usb2/2-1/2-1:1.1/0003:046D:C31C.0007
add@/devices/platform/xxxxx-ehci-1.0/usb2/2-1/2-1:1.1/input/input7
add@/devices/platform/xxxxx-ehci-1.0/usb2/2-1/2-1:1.1/input/input7/event2
add@/devices/platform/xxxxx-ehci-1.0/usb2/2-1/2-1:1.1/0003:046D:C31C.0007/hidraw/hidraw1


remove@/devices/platform/xxxxx-ehci-1.0/usb2/2-1/2-1:1.0/input/input6/event1
remove@/devices/platform/xxxxx-ehci-1.0/usb2/2-1/2-1:1.0/input/input6
remove@/devices/platform/xxxxx-ehci-1.0/usb2/2-1/2-1:1.0/0003:046D:C31C.0006/hidraw/hidraw0
remove@/devices/platform/xxxxx-ehci-1.0/usb2/2-1/2-1:1.0/0003:046D:C31C.0006
remove@/devices/platform/xxxxx-ehci-1.0/usb2/2-1/2-1:1.0
remove@/devices/platform/xxxxx-ehci-1.0/usb2/2-1/2-1:1.1/input/input7/event2
remove@/devices/platform/xxxxx-ehci-1.0/usb2/2-1/2-1:1.1/input/input7
remove@/devices/platform/xxxxx-ehci-1.0/usb2/2-1/2-1:1.1/0003:046D:C31C.0007/hidraw/hidraw1
remove@/devices/platform/xxxxx-ehci-1.0/usb2/2-1/2-1:1.1/0003:046D:C31C.0007
remove@/devices/platform/xxxxx-ehci-1.0/usb2/2-1/2-1:1.1
remove@/devices/platform/xxxxx-ehci-1.0/usb2/2-1




add@/devices/platform/xxxxx-ehci-1.0/usb2/2-1
add@/devices/platform/xxxxx-ehci-1.0/usb2/2-1/2-1:1.0
add@/devices/platform/xxxxx-ehci-1.0/usb2/2-1/2-1:1.0/0003:03F0:1F4A.0008
add@/devices/platform/xxxxx-ehci-1.0/usb2/2-1/2-1:1.0/input/input8
add@/devices/platform/xxxxx-ehci-1.0/usb2/2-1/2-1:1.0/input/input8/mouse0
add@/devices/platform/xxxxx-ehci-1.0/usb2/2-1/2-1:1.0/input/input8/event1
add@/devices/platform/xxxxx-ehci-1.0/usb2/2-1/2-1:1.0/0003:03F0:1F4A.0008/hidraw/hidraw0


remove@/devices/platform/xxxxx-ehci-1.0/usb2/2-1/2-1:1.0/input/input8/mouse0
remove@/devices/platform/xxxxx-ehci-1.0/usb2/2-1/2-1:1.0/input/input8/event1
remove@/devices/platform/xxxxx-ehci-1.0/usb2/2-1/2-1:1.0/input/input8
remove@/devices/platform/xxxxx-ehci-1.0/usb2/2-1/2-1:1.0/0003:03F0:1F4A.0008/hidraw/hidraw0
remove@/devices/platform/xxxxx-ehci-1.0/usb2/2-1/2-1:1.0/0003:03F0:1F4A.0008
remove@/devices/platform/xxxxx-ehci-1.0/usb2/2-1/2-1:1.0
remove@/devices/platform/xxxxx-ehci-1.0/usb2/2-1

前面的add和remove是USB Keyboard的，后面是USB Mouse的，从中可以看到有Mouse的信息，其中xxxxx是平台相关定义的，打印出来，但是Keyboard插拔时，没有能够体现Keyboard的信息。

还需要继续深究，先做一个记录