NAME

       CURLOPT_HSTSWRITEFUNCTION - write callback for HSTS hosts

SYNOPSIS

       #include <curl/curl.h>

       CURLSTScode hstswrite(CURL *easy, struct curl_hstsentry *sts,
                             struct curl_index *count, void *userp);

       CURLcode curl_easy_setopt(CURL *handle, CURLOPT_HSTSWRITEFUNCTION, hstswrite);

DESCRIPTION

       Pass a pointer to your callback function, as the prototype shows above.

       This  callback function gets called by libcurl repeatedly to allow the application to store the in-memory
       HSTS cache when libcurl is about to discard it.

       Set the userp argument with the CURLOPT_HSTSWRITEDATA(3) option or it will be NULL.

       When the callback is invoked, the sts pointer points to a populated struct: Read the host name to  'name'
       (it  is  'namelen' bytes long and null terminated. The 'includeSubDomains' field is non-zero if the entry
       matches subdomains. The 'expire' string is a date stamp null-terminated string using the syntax  YYYYMMDD
       HH:MM:SS.

       The  callback  should  return  CURLSTS_OK if it succeeded and is prepared to be called again (for another
       host) or CURLSTS_DONE if there's nothing more to do. It can also return CURLSTS_FAIL to signal error.

       This option does not enable HSTS, you need to use CURLOPT_HSTS_CTRL(3) to do that.

DEFAULT

       NULL - no callback.

PROTOCOLS

       This feature is only used for HTTP(S) transfer.

EXAMPLE

       {
         /* set HSTS read callback */
         curl_easy_setopt(curl, CURLOPT_HSTSWRITEFUNCTION, hstswrite);

         /* pass in suitable argument to the callback */
         curl_easy_setopt(curl, CURLOPT_HSTSWRITEDATA, &hstspreload[0]);

         result = curl_easy_perform(curl);
       }

AVAILABILITY

       Added in 7.74.0

RETURN VALUE

       This will return CURLE_OK.

SEE ALSO

       CURLOPT_HSTSWRITEDATA(3), CURLOPT_HSTSWRITEFUNCTION(3), CURLOPT_HSTS(3), CURLOPT_HSTS_CTRL(3),