CURLOPT_ALTSVC - set alt-svc cache file name
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_ALTSVC, char *filename);
Warning: this feature is early code and is marked as experimental. It can only
be enabled by explicitly telling configure with --enable-alt-svc. You
are advised to not ship this in production before the experimental label is
Pass in a pointer to a filename to instruct libcurl to use that file as
the Alt-Svc cache to read existing cache contents from and possibly also write
it back to a after a transfer, unless CURLALTSVC_READONLYFILE is set in
Specify a blank file name ("") to make libcurl not load
from a file at all.
NULL. The alt-svc cache is not read nor written to file.
CURL *curl = curl_easy_init();
curl_easy_setopt(curl, CURLOPT_ALTSVC_CTRL, CURLALTSVC_H1);
curl_easy_setopt(curl, CURLOPT_ALTSVC, "altsvc-cache.txt");
Added in 7.64.1
Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.