CURLOPT_SSL_ENABLE_ALPN(3)

1CURLOPT_SSL_ENABLE_ALPN(3)          libcurl         CURLOPT_SSL_ENABLE_ALPN(3)
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NAME

6       CURLOPT_SSL_ENABLE_ALPN - Application Layer Protocol Negotiation
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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 npn);
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DESCRIPTION

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

20       1, enabled
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PROTOCOLS

23       HTTP
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EXAMPLE

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

35       Added in 7.36.0
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RETURN VALUE

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