网络编程常用函数

• 获取网口ip地址

  char *interface2ip(char *infName) {
  struct ifaddrs *ifAddrStruct;
  void *tmpAddrPtr=NULL;
  char ip[16];
  memset(ip, 0, sizeof(ip));
  static char infIP[16];
  getifaddrs(&ifAddrStruct);
  while (ifAddrStruct != NULL)
  {
      if (ifAddrStruct->ifa_addr->sa_family==AF_INET && 0 == strcmp(ifAddrStruct->ifa_name,infName))
      {
          tmpAddrPtr=&((struct sockaddr_in *)ifAddrStruct->ifa_addr)->sin_addr;
          inet_ntop(AF_INET, tmpAddrPtr, ip, INET_ADDRSTRLEN);
          //printf("eth0 ip :%s\n",ip);
          strcpy(infIP,ip);
          //printf("infIP is :%s\n",infIP);
      }
      ifAddrStruct=ifAddrStruct->ifa_next;
  }
  //free ifaddrs
  freeifaddrs(ifAddrStruct);
  //return 0;
  return infIP;
  }

char infName[] = "eth0";
    char *ip = interface2ip(infName);
    LOG(INFO) << "eth0 ip " << ip;