CURLOPT_HSTSREADDATA(3) Library Functions Manual CURLOPT_HSTSREADDATA(3)
NAME
CURLOPT_HSTSREADDATA - pointer passed to the HSTS read callback
SYNOPSIS
#include <curl/curl.h>
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_HSTSREADDATA, void *pointer);
DESCRIPTION
Data pointer to pass to the HSTS read function. If you use the
CURLOPT_HSTSREADFUNCTION(3) option, this is the pointer you 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.
DEFAULT
NULL
PROTOCOLS
This functionality affects http only
EXAMPLE
struct MyData {
void *custom;
};
static CURLSTScode hsts_cb(CURL *easy, struct curl_hstsentry *sts,
void *clientp)
{
/* populate the struct as documented */
return CURLSTS_OK;
}
int main(void)
{
CURL *curl = curl_easy_init();
struct MyData this;
if(curl) {
CURLcode result;
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);
/* set HSTS read callback */
curl_easy_setopt(curl, CURLOPT_HSTSREADFUNCTION, hsts_cb);
result = curl_easy_perform(curl);
curl_easy_cleanup(curl);
}
}
AVAILABILITY
Added in curl 7.74.0
RETURN VALUE
This returns CURLE_OK.
SEE ALSO
CURLOPT_HSTS(3), CURLOPT_HSTSREADFUNCTION(3), CURLOPT_HSTSWRITEDATA(3),
CURLOPT_HSTSWRITEFUNCTION(3)
libcurl 2026-06-09 CURLOPT_HSTSREADDATA(3)
curl 8.20.0 - Generated Tue Jun 9 15:59:38 CDT 2026