获取本机ip和外网ip地址

//获取外网地址
void GetNetIPAddress(__out std::string& IpAddr)
{
static std::string LocalIpAddr;

if(LocalIpAddr.empty())
{
char pName[256] = {0};

gethostname(pName,sizeof(pName));

hostent *pHost = gethostbyname(pName);

string str;

HRESULT hr = URLDownloadToFile(0,_T("http://iframe.ip138.com/ic.asp"),_T("ip.ini"),0,NULL);

if(S_OK == hr)
{
FILE *pFile = fopen("ip.ini","r");

LONG curpos = ftell(pFile);

fseek(pFile,0,SEEK_END);

LONG length = ftell(pFile);

fseek(pFile,curpos,SEEK_SET);

char *pData = new char[length+1];

fread(pData,length,1,pFile);

fclose(pFile);

str = pData;

int nIndex1 = str.find('[');

int nIndex2 = str.find(']');

LocalIpAddr = str.substr(nIndex1+1,nIndex2-nIndex1-1);
}
else
{
LocalIpAddr = inet_ntoa(*((in_addr*)pHost->h_addr));
}
}

IpAddr = LocalIpAddr;
}


//获取本机地址
int GetLocalIPAddress(__out std::string& IpAddr)
{
char host_name[255] = "0"; 
//获取本地主机名称 
if(gethostname(host_name, sizeof(host_name)) == SOCKET_ERROR) 
{ 
return 1;
} 

//从主机名数据库中得到对应的“主机” 
struct hostent *phe = gethostbyname(host_name); 
if (phe == 0) 
{ 
return 1;
} 

//循环得出本地机器所有IP地址 
for(int i = 0; phe->h_addr_list[i] != 0; ++i) 
{ 
struct in_addr addr; 
memcpy(&addr, phe->h_addr_list[i], sizeof(struct in_addr)); 

IpAddr = inet_ntoa(addr);
return 0;
}

return 1;
}