NAME

       CURLOPT_HSTSREADFUNCTION - read callback for HSTS hosts

SYNOPSIS

       #include <curl/curl.h>

       CURLSTScode hstsread(CURL *easy, struct curl_hstsentry *sts, void *userp);

       CURLcode curl_easy_setopt(CURL *handle, CURLOPT_HSTSREADFUNCTION, hstsread);

DESCRIPTION

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

       This callback function gets called by libcurl repeatedly when it populates the in-memory HSTS cache.

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

       When this callback is invoked, the sts pointer points to a populated struct: Copy the host name to 'name'
       (no  longer than 'namelen' bytes). Make it null-terminated. Set 'includeSubDomains' to TRUE or FALSE. Set
       'expire' to a date stamp or a zero length string for *forever* (wrong date stamp format might  cause  the
       name to not get accepted)

       The  callback  should  return  CURLSTS_OK  if  it  returns a name and is prepared to be called again (for
       another host) or CURLSTS_DONE if it has no entry to return. It can also  return  CURLSTS_FAIL  to  signal
       error.    Returning   CURLSTS_FAIL   will   stop   the   transfer   from   being   performed   and   make
       CURLE_ABORTED_BY_CALLBACK get returned.

       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_HSTSREADFUNCTION, hstsread);

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

         result = curl_easy_perform(curl);
       }

AVAILABILITY

       Added in 7.74.0

RETURN VALUE

       This will return CURLE_OK.

SEE ALSO

       CURLOPT_HSTSREADDATA(3), CURLOPT_HSTSWRITEFUNCTION(3), CURLOPT_HSTS(3), CURLOPT_HSTS_CTRL(3),

libcurl 7.81.0                                  November 26, 2021                    CURLOPT_HSTSREADFUNCTION(3)