$ curl -V
curl 7.71.0 (x86_64-pc-linux-gnu) libcurl/7.71.0 OpenSSL/1.0.2u zlib/1.2.7 libssh2/1.8.0
Release-Date: 2020-06-24
Protocols: dict file ftp ftps gopher http https imap imaps pop3 pop3s rtsp scp sftp smb smbs smtp smtps telnet tftp
Features: AsynchDNS HTTPS-proxy IPv6 Largefile libz NTLM NTLM_WB SSL TLS-SRP UnixSockets
$ curl -B ftp://ip/welcome.msg -o /dev/null -v
*   Trying ip:21...
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
  0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0* Connected to ip (ip) port 21 (#0)
  0     0    0     0    0     0      0      0 --:--:--  0:00:09 --:--:--     0< 220 ProFTPD 1.3.5b Server (Debian) [ip]
> USER anonymous
  0     0    0     0    0     0      0      0 --:--:--  0:00:10 --:--:--     0< 331 Anonymous login ok, send your complete email address as your password
> PASS ftp@example.com
< 230-Welcome, archive user anonymous@ip !
< 230-
< 230-The local time is: Fri Feb 04 12:28:16 2011
< 230-
< 230-This is an experimental FTP server.  If you have any unusual problems,
< 230-please report them via e-mail to <root@>.
< 230-
< 230 Anonymous access granted, restrictions apply
> PWD
< 257 "/" is the current directory
* Entry path is '/'
* Request has same path as previous transfer
> EPSV
* Connect data stream passively
* ftp_perform ends with SECONDARY: 0
< 229 Entering Extended Passive Mode (|||2128|)
*   Trying ip:2128...
* Connecting to ip (ip) port 2128
* Connected to ip (ip) port 21 (#0)
> TYPE A
< 200 Type set to A
> SIZE welcome.msg
< 550 SIZE not allowed in ASCII mode
> RETR welcome.msg
< 150 Opening ASCII mode data connection for welcome.msg (170 bytes)
* Maxdownload = -1
* Getting file with size: -1
{ [177 bytes data]
* Remembering we are in dir ""
< 226 Transfer complete
100   177    0   177    0     0     16      0 --:--:--  0:00:10 --:--:--    40
* Connection #0 to host ip left intact