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* Copyright (C) 1998 - 2021, Daniel Stenberg, <daniel@haxx.se>, et al.
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CURLOPT_HSTSREADDATA - pointer passed to the HSTS read callback #include <curl/curl.h> CURLcode curl_easy_setopt(CURL *handle, CURLOPT_HSTSREADDATA, void *pointer); Data pointer to pass to the HSTS read function. If you use the CURLOPT_HSTSREADFUNCTION(3) option, this is the pointer you will get as input in the 3rd argument to the callback. This option does not enable HSTS, you need to use CURLOPT_HSTS_CTRL(3) to do that. NULL This feature is only used for HTTP(S) transfer.

CURL *curl = curl_easy_init();
struct MyData this;
if(curl) {
 curl_easy_setopt(curl, CURLOPT_URL, "http://example.com");

 /* pass pointer that gets passed in to the
 CURLOPT_HSTSREADFUNCTION callback */
 curl_easy_setopt(curl, CURLOPT_HSTSREADDATA, &this);

 curl_easy_perform(curl);
}

Added in 7.74.0 This will return CURLE_OK. CURLOPT_HSTSREADFUNCTION "(3), " CURLOPT_HSTSWRITEDATA "(3), " CURLOPT_HSTSWRITEFUNCTION "(3), "