获得本机IP地址

#include <Winsock2.h>
#include <string>
#include <iostream>
using namespace std;

#pragma comment(lib, "WS2_32.lib")

void main()
{
 //Socket初始化部分
 WORD wVersionRequested;
 WSADATA wsaData;
 int err;

 wVersionRequested = MAKEWORD(2, 2);

 err = WSAStartup(wVersionRequested, &wsaData);
 if (err != 0)
 {
  cout << "Initialize failed!" << endl;
  return;
 }

 if (LOBYTE( wsaData.wVersion ) != 2 ||
  HIBYTE( wsaData.wVersion ) != 2)
 {
  WSACleanup( );
  cout << "Initialize failed!" << endl;
  return;
 }

 //通过本机主机名.
 char host_name[256];
 gethostname(host_name,sizeof(host_name));

 struct hostent  *hp;
 struct in_addr  sa;
 char    *buf;

 hp = gethostbyname(host_name);

 if (hp != NULL)
 {
  //循环获取本地主机名
  for (int i = 0; hp->h_addr_list[i]; i++)
  {
   memcpy (&sa, hp->h_addr_list[i],hp->h_length);

   buf = inet_ntoa(sa);
   cout << "The host IP is:" << buf << endl;
  }
 }

 WSACleanup();
}