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),