CURLOPT_PRIVATE - store a private pointer

Added in curl 7.10.3

NULL

Pass a void * as parameter, pointing to data that should be associated with this curl handle. The pointer can subsequently be retrieved using curl_easy_getinfo(3) with the CURLINFO_PRIVATE(3) option. libcurl itself never does anything with this data.

struct private { void *custom; }; int main(void) { CURL *curl = curl_easy_init(); struct private secrets; if(curl) { struct private *extracted; curl_easy_setopt(curl, CURLOPT_URL, "https://example.com"); /* store a pointer to our private struct */ curl_easy_setopt(curl, CURLOPT_PRIVATE, &secrets); curl_easy_perform(curl); /* we can extract the private pointer again too */ curl_easy_getinfo(curl, CURLINFO_PRIVATE, &extracted); } }

CURLOPT_PRIVATE - store a private pointer

This functionality affects all supported protocols

curl_easy_setopt(3) returns a CURLcode indicating success or error. CURLE_OK (0) means everything was OK, non-zero means an error occurred, see libcurl-errors(3).

CURLINFO_PRIVATE(3), CURLOPT_STDERR(3), CURLOPT_VERBOSE(3) libcurl 2025-06-16 CURLOPT_PRIVATE(3)

#include <curl/curl.h> CURLcode curl_easy_setopt(CURL *handle, CURLOPT_PRIVATE, void *pointer);