linux下检测U盘插入并读取文件_imx6ull linux u盘插入检测

由于NETLINK是Linux内置功能，所以使用起来很简单：创建一个AF_NETLINK协议族下NETLINK_KOBJECT_UEVENT类型的特殊文件描述符（套结字）CppLive，然后利用setsocketopt允许该文件描述符（套结字）复用其他端口，再利用band函数将自身进程绑定到特殊文件描述符（套结字）CppLive，最后利用select在while循环内监听CppLive是否可读，如果可读则调用recv接收Linux系统内核传递过来的数据并打印出来，这些输出便是USB热插拔信息。当然你也可以个性化地处理来自内核的热插拔信息，让程序变得更加智能以及人性化。

建立NET_LINK套接字,与内核通信实时检测U状态(与基本的套接字编程基本一致) 

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

#define UEVENT_BUFFER_SIZE 2048

static int init_hotplug_sock(void);

int main(int argc, char* argv[])
{
int hotplug_sock = init_hotplug_sock();
while(1){
char buf[UEVENT_BUFFER_SIZE*2] = {0};
recv(hotplug_sock, &buf, sizeof(buf), 0); 
printf("%s\n", buf);

}
return 0;
}

static int init_hotplug_sock(void)
{
struct sockaddr_nl snl;
const int buffersize = 16 * 1024 * 1024;
int retval;

memset(&snl, 0x00, sizeof(struct sockaddr_nl));
snl.nl_family = AF_NETLINK;
snl.nl_pid = getpid();
snl.nl_groups = 1;
int hotplug_sock = 

socket(PF_NETLINK, SOCK_DGRAM, NETLINK_KOBJECT_UEVENT);

if (hotplug_sock == -1) {
printf("error getting socket: %s", strerror(errno));
return -1;
}

/* set receive buffersize */
setsockopt(hotplug_sock, 

SOL_SOCKET, SO_RCVBUFFORCE, 

&buffersize, sizeof(buffersize));

retval = bind(hotplug_sock,

 (struct sockaddr *) &snl, 

sizeof(struct sockaddr_nl));

if (retval < 0) {
printf("bind failed: %s", strerror(errno));
close(hotplug_sock);
hotplug_sock = -1;
return -1;
}

return hotplug_sock;
}