vc 获取外网ip

int GetWan(char *ww)   
{
WSAData wsaDat; 
short int Port = 80; 
WSAStartup(MAKEWORD(1,1),&wsaDat); 
SOCKET sd = socket(AF_INET, SOCK_STREAM, 0);
SOCKADDR_IN sockAddr; 
memset((void*)&sockAddr,0,sizeof(sockAddr)); 
sockAddr.sin_family=AF_INET;
sockAddr.sin_port=htons(Port); 
sockAddr.sin_addr.s_addr=inet_addr("219.153.15.76");
connect(sd, 
   (LPSOCKADDR)&sockAddr, 
   sizeof(sockAddr)); 
char sendstr[]="GET /ip2city.asp HTTP/1.1\r\nAccept: */*\r\nReferer: ******\r\nUser-Agent: Mozilla/4.0\r\nHost: www.ip138.com\r\nConnection: close\r\n\r\n\0"; 
char* p; 
int iLen = strlen(sendstr); 
p = sendstr; 
while (iLen)
{ 
   int iRet = send(sd,p,iLen,0); 
   if (iRet > 0) 
   { 
    p += iRet; 
    iLen -= iRet; 
    continue; 
   } 
   return 0; 
} 
char recvstr[1024]; 
memset(recvstr,0,1024); 
p = recvstr; 
char* iIndex_Head ; 
iLen = 1024; 
int need_len = -1; 
while (iLen)
{ 
   int iRet = recv(sd,p,iLen,0); 
   if (iRet <= 0) 
   { 
    return 0; 
   } 
   p += iRet; 
   iLen -= iRet; 
   if ((iIndex_Head = strstr(recvstr,"\r\n\r\n"))&&(need_len==-1)) 
   { 
    char* iIndex = strstr(recvstr,"Content-Length:"); 
    if (!iIndex) 
    { 
     continue; 
    } 
    char *p1 = iIndex + strlen("Content-Length:"); 
    need_len = iIndex_Head - recvstr + 2 + atol(p1); 
   
   } 
   if (1024 - iLen >=need_len) { break; 
  
   } 
} 
char *p1 = strstr(iIndex_Head,"["); 
char *p0 = strstr(p1,"]"); 
*p0 = '\0';
strcpy(ww,p1+1);
closesocket(sd); 
WSACleanup();
return atoi(ww);
}

转载于:https://www.cnblogs.com/rogee/archive/2011/04/30/2033403.html