Long: proto-default Help: Use PROTOCOL for any URL missing a scheme Arg: <protocol> Added: 7.45.0 --- Tells curl to use \fIprotocol\fP for any URL missing a scheme name. Example: curl --proto-default https ftp.mozilla.org An unknown or unsupported protocol causes error \fICURLE_UNSUPPORTED_PROTOCOL\fP (1). This option does not change the default proxy protocol (http). Without this option curl would make a guess based on the host, see --url for details.