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.

       If  you  are  using  libcurl  as  a  win32 DLL, you MUST use a CURLOPT_WRITEFUNCTION(3) or
       CURLOPT_HEADERFUNCTION(3) if you set this option or you will experience crashes.

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),