C语言实现linux网卡检测精简版

#include <stdlib.h>#include <stdio.h>#include <string.h> #include <sys/socket.h>#include <sys/ioctl.h>#include <linux/if.h>#include <ifaddrs.h>#include <arpa/inet.h>   int c_ifaddrs_netlink_status(const char *if_name ){ struct ifaddrs *ifa = NULL, *ifList;   if (getifaddrs(&ifList) < 0) { return -1; }  for (ifa = ifList; ifa != NULL; ifa = ifa->ifa_next)  { if(ifa->ifa_addr->sa_family == AF_INET)  {  if(strcmp(ifa->ifa_name, if_name) ==0)  {  if(!(ifa->ifa_flags & IFF_UP))  {   printf("DEVICE_DOWN/r/n");   freeifaddrs(ifList);   return 1;  }   if(!(ifa->ifa_flags & IFF_RUNNING))  {   printf("DEVICE_UNPLUGGED/r/n");   freeifaddrs(ifList);   return 2;  }   printf("DEVICE_LINKED/r/n");  freeifaddrs(ifList);  return 3;  } }  }   printf(stderr, "DEVICE_NONE/r/n"); freeifaddrs(ifList); return 0;} int main(int argc, char* argv[]){ int i=0; if(argc != 2) { fprintf(stderr, "usage: %s <ethname>/r/n", argv[0]); return -1; }  i = c_ifaddrs_netlink_status(argv[1]);  fprintf(stderr,"c_ifaddrs_netlink_status if_status = %d/n", i ); return 0;}