NAME

       CURLOPT_HSTS - HSTS cache file name

SYNOPSIS

       #include <curl/curl.h>

       CURLcode curl_easy_setopt(CURL *handle, CURLOPT_HSTS, char *filename);

DESCRIPTION

       Make  the  filename  point  to a file name to load an existing HSTS cache from, and to store the cache in
       when the easy handle is closed. Setting a file name with this option  will  also  enable  HSTS  for  this
       handle (the equivalent of setting CURLHSTS_ENABLE with CURLOPT_HSTS_CTRL(3)).

       If the given file does not exist or contains no HSTS entries at startup, the HSTS cache will simply start
       empty. Setting the file name to NULL or "" will only enable HSTS without reading from or writing  to  any
       file.

       If  this option is set multiple times, libcurl will load cache entries from each given file but will only
       store the last used name for later writing.

FILE FORMAT

       The HSTS cache is saved to and loaded from a text file with one entry per physical line. Each line in the
       file has the following format:

       [host] [stamp]

       [host]  is  the  domain name for the entry and the name is dot-prefixed if it is a includeSubDomain entry
       (if the entry is valid for all subdmains to the name as well or only for the exact name).

       [stamp] is the time (in UTC) when the entry expires and it uses the format "YYYYMMDD HH:MM:SS".

       Lines starting with "#" are treated as comments and are ignored. There is currently  no  length  or  size
       limit.

DEFAULT

       NULL, no file name

PROTOCOLS

       HTTPS and HTTP

EXAMPLE

       CURL *curl = curl_easy_init();
       if(curl) {
         curl_easy_setopt(curl, CURLOPT_HSTS, "/home/user/.hsts-cache");
         curl_easy_perform(curl);
       }

AVAILABILITY

       Added in 7.74.0

RETURN VALUE

       Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.

SEE ALSO

       CURLOPT_HSTS_CTRL(3), CURLOPT_ALTSVC(3), CURLOPT_RESOLVE(3),