c: Copyright (C) 1998 - 2022, Daniel Stenberg, <daniel@haxx.se>, et al.
SPDX-License-Identifier: curl
Long: ftp-port
Arg: <address>
Help: Use PORT instead of PASV
Short: P
Protocols: FTP
See-also: ftp-pasv disable-eprt
Category: ftp
Example: -P - ftp:/example.com
Example: -P eth0 ftp:/example.com
Example: -P 192.168.0.2 ftp:/example.com
Added: 4.0
---
Reverses the default initiator/listener roles when connecting with FTP. This
option makes curl use active mode. curl then tells the server to connect back
to the client's specified address and port, while passive mode asks the server
to setup an IP address and port for it to connect to. <address> should be one
of:
.RS
.IP interface
e.g. "eth0" to specify which interface's IP address you want to use (Unix only)
.IP "IP address"
e.g. "192.168.10.1" to specify the exact IP address
.IP "host name"
e.g. "my.host.domain" to specify the machine
.IP "-"
make curl pick the same IP address that is already used for the control
connection
.RE

If this option is used several times, the last one will be used. Disable the
use of PORT with --ftp-pasv. Disable the attempt to use the EPRT command
instead of PORT by using --disable-eprt. EPRT is really PORT++.

You can also append \&":[start]-[end]\&" to the right of the address, to tell
curl what TCP port range to use. That means you specify a port range, from a
lower to a higher number. A single number works as well, but do note that it
increases the risk of failure since the port may not be available.
(Added in 7.19.5)