CURLOPT_HEADERDATA man page

CURLOPT_HEADERDATA ā€” 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, "http://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),

Referenced By

curl_easy_setopt(3), CURLOPT_HEADERFUNCTION(3), libcurl-tutorial(3).

May 05, 2017 libcurl 7.56.1 curl_easy_setopt options