some google services (clientlogin) returning 302 moved when using libcurl

Okay, so I tried using this on the comma开发者_如何学Cnd line:

curl -d accountType=GOOGLE -d Email=REDACTED@gmail.com -d Passwd=REDACTED -d service=finance -k https://www.google.com/accounts/ClientLogin

and it seems to work. Even when I pass wrong passwords, it'll tell me that there's bad authentication.

However, when I try using libcurl, it returns "302 moved", instead of badauthentication.

I mean, here's the code:

#include <curl/curl.h>

using namespace std;

int main(void)
{
  CURL *curl;
  CURLcode res;

  curl = curl_easy_init();
  if(curl) {
    curl_easy_setopt(curl, CURLOPT_URL, "https://www.gogle.com/accounts/ClientLogin");

    curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, 0L);

    CURLcode retcode = res = curl_easy_perform(curl);
    if(retcode != 0){
        cout << "ERROR DETECTED : " << retcode << endl;
    }

    /* always cleanup */ 
    curl_easy_cleanup(curl);
  }
  return 0;
}

What exactly is happening?

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Lots of sites check the user-agent field.

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