CURLOPT_SSL_ENABLE_ALPN(3)

1CURLOPT_SSL_ENABLE_ALPN(3) curl_easy_setopt options CURLOPT_SSL_ENABLE_ALPN(3)
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NAME

6       CURLOPT_SSL_ENABLE_ALPN - enable ALPN
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SYNOPSIS

9       #include <curl/curl.h>
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11       CURLcode  curl_easy_setopt(CURL  *handle, CURLOPT_SSL_ENABLE_ALPN, long
12       npn);
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DESCRIPTION

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

21       1, enabled
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PROTOCOLS

24       HTTP
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EXAMPLE

27       CURL *curl = curl_easy_init();
28       if(curl) {
29         curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/");
30         curl_easy_setopt(curl, CURLOPT_SSL_ENABLE_ALPN, 0L);
31         ret = curl_easy_perform(curl);
32         curl_easy_cleanup(curl);
33       }
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AVAILABILITY

36       Added in 7.36.0
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RETURN VALUE

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