CURLOPT_DEFAULT_PROTOCOL − default protocol to use if the URL is missing a scheme name
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_DEFAULT_PROTOCOL, char *protocol);
This option tells libcurl to use protocol if the URL is missing a scheme name.
Use one of these protocol (scheme) names:
dict, file, ftp, ftps, gopher, http, https, imap, imaps, ldap, ldaps, pop3, pop3s, rtsp, scp, sftp, smb, smbs, smtp, smtps, telnet, tftp
An unknown or unsupported protocol causes error CURLE_UNSUPPORTED_PROTOCOL when libcurl parses a schemeless URL. Parsing happens when curl_easy_perform(3) or curl_multi_perform(3) is called. The protocols supported by libcurl will vary depending on how it was built. Use curl_version_info(3) if you need a list of protocol names supported by the build of libcurl that you are using.
This option does not change the default proxy protocol (http).
Without this option libcurl would make a guess based on the host, see CURLOPT_URL(3) for details.
The application does not have to keep the string around after setting this option.
NULL (make a guess based on the host)
/* set a URL without a scheme */
curl_easy_setopt(curl, CURLOPT_URL, "example.com");
/* set the
default protocol (scheme) for schemeless URLs */
curl_easy_setopt(curl, CURLOPT_DEFAULT_PROTOCOL, "https");
/* Perform the
Added in 7.45.0
CURLE_OK if the option is supported.
CURLE_OUT_OF_MEMORY if there was insufficient heap space.
CURLE_UNKNOWN_OPTION if the option is not supported.