CURLOPT_HSTSWRITEFUNCTION(3curl_easy_setopt optionCURLOPT_HSTSWRITEFUNCTION(3)
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 noth-
ing 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), CUR-
LOPT_HSTS(3), CURLOPT_HSTS_CTRL(3),
libcurl 7.81.0 November 26, 2021 CURLOPT_HSTSWRITEFUNCTION(3)
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