CURLOPT_HEADERDATA (original) (raw)

CURLOPT_HEADERDATA explained

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 or CURLOPT_HEADERFUNCTION is used, pointer is passed in to the respective callback.

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

If you are using libcurl as a Windows DLL, you MUST use a CURLOPT_WRITEFUNCTION or CURLOPT_HEADERFUNCTION if you set this option or you might experience crashes.

Default

NULL

Protocols

This functionality affects all supported protocols

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 = userdata; printf("shoe size: %d\n", i->shoesize); / now this callback can access the my_info struct */ return nitems * size; } int main(void) { 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

Added in curl 7.10

Return value

Returns CURLE_OK