lib curl in c++ disable printing - c++

Question

i got a small program from http://curl.haxx.se/ and while i run it always prints the webpage how can i disable the printing function
#include <iostream>
#include <curl/curl.h>
using namespace std;
int main() {
CURL *curl;
CURLcode res;
curl = curl_easy_init();
if(curl) {
curl_easy_setopt(curl, CURLOPT_URL, "http://google.com");
curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION,1);
res = curl_easy_perform(curl);
/* always cleanup */
curl_easy_cleanup(curl);
}
return 0;
}

Answer 1

You need to set up a CURLOPT_WRITEFUNCTION to make it not use stdout.
There is an explanation here (under CURLOPT_WRITEFUNCTION):
http://curl.haxx.se/libcurl/c/curl_easy_setopt.html
and here (Under "Handling the Easy libcurl):
http://curl.haxx.se/libcurl/c/libcurl-tutorial.html
Basically adding the function:
size_t write_data(void *buffer, size_t size, size_t nmemb, void *userp)
{
return size * nmemb;
}
and calling
curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, write_data);
Should do it.

Answer 2

You can still get diagnostic messages. To stop these either change or add the following line:
curl_easy_setopt (curl, CURLOPT_VERBOSE, 0L); //0 disable messages

Answer 3

To write data into file instead of printing, give a file descriptor as:
FILE *wfd = fopen("foo.txt", "w");
...
curl_easy_setopt(curl, CURLOPT_WRITEDATA, wfd);
curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, NULL);

Answer 4

What worked for me was using the CURLOPT_NOBODY option in the code, referenced here: http://curl.haxx.se/libcurl/c/curl_easy_setopt.html#CURLOPTNOBODY
#include <iostream>
#include <curl/curl.h>
using namespace std;
int main() {
CURL *curl;
CURLcode res;
curl = curl_easy_init();
if(curl) {
curl_easy_setopt(curl, CURLOPT_URL, "http://google.com");
curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION,1);
//USING CURLOPT NOBODY
curl_easy_setopt(curl, CURLOPT_NOBODY,1);
res = curl_easy_perform(curl);
/* always cleanup */
curl_easy_cleanup(curl);
}
return 0;
}