External IP Address [duplicate]

This question already has answers here: 开发者_Go百科 Closed 11 years ago.

Possible Duplicate:

Stable way of retrieving the external IP for a host behind a NAT

Well, hello again. I was wondering how do i get the External IP Address (External since some people haves router) of the computer?

---

Write a program and use HTTP protocol to connect to some external websites such as this one: http://www.whatismyip.com/

Then write a parser to parse out: Your IP Address Is: xxx.xxx.xxx.xxx

Voila.

---

Here's one way of using user's suggestion ... of course this only works for your own ip which you could also determine by opening the command prompt and running ipconfig /all

#include <windows.h>
#include <wininet.h>
#include <iostream>

#pragma comment(lib, "wininet")

int main(int argc, char* argv[])
{
    HINTERNET hInternet, hFile;
    DWORD rSize;
    char buffer[32];

    hInternet = InternetOpen(NULL, INTERNET_OPEN_TYPE_PRECONFIG, NULL, NULL, 0);
    hFile = InternetOpenUrl(hInternet, "http://automation.whatismyip.com/n09230945.asp", NULL, 0, INTERNET_FLAG_RELOAD, 0);
    InternetReadFile(hFile, &buffer, sizeof(buffer), &rSize);
    buffer[rSize] = '\0';

    InternetCloseHandle(hFile);
    InternetCloseHandle(hInternet);

    std::cout << "Your IP Address: " << buffer << "\n";
    system("pause");
    return 0;
}   

FYI: The owner's of http://www.whatismyip.com/ request that you only hit this automation page once every 5 minutes so I feel compelled to put a caveat not to run this code more often than that as well :P

Note: http://automation.whatismyip.com/n09230945.asp is the newest address for the automation file. the 5 minute / 300 second rule is still in place.