CURLOPT_SSL_ENABLE_ALPN(3)                            curl_easy_setopt options

NAME
       CURLOPT_SSL_ENABLE_ALPN - enable ALPN

SYNOPSIS
       #include <curl/curl.h>

       CURLcode curl_easy_setopt(CURL *handle, CURLOPT_SSL_ENABLE_ALPN, long
       npn);

DESCRIPTION
       Pass a long as parameter, 0 or 1 where 1 is for enable and 0 for
       disable. This option enables/disables ALPN in the SSL handshake (if the
       SSL backend libcurl is built to use supports it), which can be used to
       negotiate http2.

DEFAULT
       1, enabled

PROTOCOLS
       HTTP

EXAMPLE
       CURL *curl = curl_easy_init();
       if(curl) {
         curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/");
         curl_easy_setopt(curl, CURLOPT_SSL_ENABLE_ALPN, 0L);
         ret = curl_easy_perform(curl);
         curl_easy_cleanup(curl);
       }

AVAILABILITY
       Added in 7.36.0

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

SEE ALSO
       CURLOPT_SSL_ENABLE_NPN(3), CURLOPT_SSL_OPTIONS(3),

libcurl 7.77.0                 November 4, 2020     CURLOPT_SSL_ENABLE_ALPN(3)