CURLOPT_DEFAULT_PROTOCOL - default protocol to use if the URL is missing a
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_DEFAULT_PROTOCOL, char
This option tells libcurl to use protocol
if the URL is missing a scheme
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
when libcurl parses a schemeless URL.
Parsing happens when curl_easy_perform(3)
is called. The protocols supported by libcurl
will vary depending on how it was built. Use curl_version_info(3)
you need a list of protocol names supported by the build of libcurl that you
This option does not change the default proxy protocol (http).
Without this option libcurl would make a guess based on the host, see
The application does not have to keep the string around after setting this
NULL (make a guess based on the host)
curl = curl_easy_init();
/* 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 request */
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.