Program for device hot swapping in Linux

/** * This program's outputs. * root@slax:~# ./a.out remove@/devices/pci0000:00/0000:00:15.0/0000:03:00.0/usb3/3-2/3-2.1/3-2.1:1.0/host5/target5:0:0/5:0:0:0/bsg/5:0:0:0change@/devices/pci0000:00/0000:00:15.0/0000:03:00.0/usb3/3-2/3-2.1/3-2.1:1.0/host5/target5:0:0/5:0:0:0/block/sdbremove@/devices/pci0000:00/0000:00:15.0/0000:03:00.0/usb3/3-2/3-2.1/3-2.1:1.0/host5/target5:0:0/5:0:0:0/scsi_device/5:0:0:0remove@/devices/pci0000:00/0000:00:15.0/0000:03:00.0/usb3/3-2/3-2.1/3-2.1:1.0/host5/target5:0:0/5:0:0:0/scsi_disk/5:0:0:0remove@/devices/pci0000:00/0000:00:15.0/0000:03:00.0/usb3/3-2/3-2.1/3-2.1:1.0/host5/target5:0:0/5:0:0:0/block/sdb/sdb1remove@/devices/virtual/bdi/8:16remove@/devices/pci0000:00/0000:00:15.0/0000:03:00.0/usb3/3-2/3-2.1/3-2.1:1.0/host5/target5:0:0/5:0:0:0/block/sdbremove@/devices/pci0000:00/0000:00:15.0/0000:03:00.0/usb3/3-2/3-2.1/3-2.1:1.0/host5/target5:0:0/5:0:0:0remove@/devices/pci0000:00/0000:00:15.0/0000:03:00.0/usb3/3-2/3-2.1/3-2.1:1.0/host5/scsi_host/host5remove@/devices/pci0000:00/0000:00:15.0/0000:03:00.0/usb3/3-2/3-2.1/3-2.1:1.0/host5remove@/devices/pci0000:00/0000:00:15.0/0000:03:00.0/usb3/3-2/3-2.1/3-2.1:1.0remove@/devices/pci0000:00/0000:00:15.0/0000:03:00.0/usb3/3-2/3-2.1remove@/host5/target5:0:0add@/devices/pci0000:00/0000:00:15.0/0000:03:00.0/usb3/3-2/3-2.1add@/devices/pci0000:00/0000:00:15.0/0000:03:00.0/usb3/3-2/3-2.1/3-2.1:1.0add@/devices/pci0000:00/0000:00:15.0/0000:03:00.0/usb3/3-2/3-2.1/3-2.1:1.0/host6add@/devices/pci0000:00/0000:00:15.0/0000:03:00.0/usb3/3-2/3-2.1/3-2.1:1.0/host6/scsi_host/host6add@/devices/pci0000:00/0000:00:15.0/0000:03:00.0/usb3/3-2/3-2.1/3-2.1:1.0/host6/target6:0:0add@/devices/pci0000:00/0000:00:15.0/0000:03:00.0/usb3/3-2/3-2.1/3-2.1:1.0/host6/target6:0:0/6:0:0:0add@/devices/pci0000:00/0000:00:15.0/0000:03:00.0/usb3/3-2/3-2.1/3-2.1:1.0/host6/target6:0:0/6:0:0:0/scsi_disk/6:0:0:0add@/devices/pci0000:00/0000:00:15.0/0000:03:00.0/usb3/3-2/3-2.1/3-2.1:1.0/host6/target6:0:0/6:0:0:0/scsi_device/6:0:0:0add@/devices/pci0000:00/0000:00:15.0/0000:03:00.0/usb3/3-2/3-2.1/3-2.1:1.0/host6/target6:0:0/6:0:0:0/bsg/6:0:0:0add@/devices/virtual/bdi/8:16add@/devices/pci0000:00/0000:00:15.0/0000:03:00.0/usb3/3-2/3-2.1/3-2.1:1.0/host6/target6:0:0/6:0:0:0/block/sdbadd@/devices/pci0000:00/0000:00:15.0/0000:03:00.0/usb3/3-2/3-2.1/3-2.1:1.0/host6/target6:0:0/6:0:0:0/block/sdb/sdb1 */#include <stdio.h>#include <errno.h>#include <string.h>#include <sys/socket.h>#include <linux/netlink.h>#define UEVENT_BUFFER_SIZE      2048static 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;}int main(int argc, char* argv[]){    int hotplug_sock = init_hotplug_sock();        while(1)    {      //printf("sunqidong debug\n");      char buf[UEVENT_BUFFER_SIZE*2] = {0};      recv(hotplug_sock, &buf, sizeof(buf), 0);      printf("%s\n", buf);    }    return 0;}