c: Copyright (C) 1998 - 2022, Daniel Stenberg, , et al. SPDX-License-Identifier: curl Long: preproxy Arg: [protocol://]host[:port] Help: Use this proxy first Added: 7.52.0 Category: proxy Example: --preproxy socks5://proxy.example -x http://http.example $URL See-also: proxy socks5 --- Use the specified SOCKS proxy before connecting to an HTTP or HTTPS --proxy. In such a case curl first connects to the SOCKS proxy and then connects (through SOCKS) to the HTTP or HTTPS proxy. Hence pre proxy. The pre proxy string should be specified with a protocol:// prefix to specify alternative proxy protocols. Use socks4://, socks4a://, socks5:// or socks5h:// to request the specific SOCKS version to be used. No protocol specified will make curl default to SOCKS4. If the port number is not specified in the proxy string, it is assumed to be 1080. User and password that might be provided in the proxy string are URL decoded by curl. This allows you to pass in special characters such as @ by using %40 or pass in a colon with %3a. If this option is used several times, the last one will be used.