NAME¶

CURLOPT_HEADERDATA - pointer to pass to header callback

SYNOPSIS¶

#include <curl/curl.h>

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_HEADERDATA, void *pointer);

DESCRIPTION¶

Pass a pointer to be used to write the header part of the received data to.

If CURLOPT_WRITEFUNCTION(3) or CURLOPT_HEADERFUNCTION(3) is used, pointer will be passed in to the respective callback.

If neither of those options are set, pointer must be a valid FILE * and it will be used by a plain fwrite() to write headers to.

DEFAULT¶

NULL

PROTOCOLS¶

All

EXAMPLE¶

struct my_info {


  int shoesize;


  char *secret;
};
static size_t header_callback(char *buffer, size_t size,


                              size_t nitems, void *userdata)
{


  struct my_info *i = (struct my_info *)userdata;


  /* now this callback can access the my_info struct */


  return nitems * size;
}
CURL *curl = curl_easy_init();
if(curl) {


  struct my_info my = { 10, "the cookies are in the cupboard" };


  curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");


  curl_easy_setopt(curl, CURLOPT_HEADERFUNCTION, header_callback);


  /* pass in custom data to the callback */


  curl_easy_setopt(curl, CURLOPT_HEADERDATA, &my);


  curl_easy_perform(curl);
}

AVAILABILITY¶

Always

RETURN VALUE¶

Returns CURLE_OK

SEE ALSO¶

CURLOPT_HEADERFUNCTION(3), CURLOPT_WRITEFUNCTION(3),