ターミナルから
ftp コマンドを実行しようとしたら、無かった。

$ ftp my.server
-bash: ftp: command not found

brew install ftp では、入らなかった。

$ brew install ftp
Error: No available formula with the name "ftp" 

https://apple.stackexchange.com/questions/299758/how-to-get-bsd-ftp-and…
を参考に
brew install inetutils した。

$ brew install inetutils
==> Installing dependencies for inetutils: libidn
==> Installing inetutils dependency: libidn
==> Downloading https://homebrew.bintray.com/bottles/libidn-1.35.mojave.bottle.tar.gz
######################################################################## 100.0%
==> Pouring libidn-1.35.mojave.bottle.tar.gz
==> Caveats
Emacs Lisp files have been installed to:
  /usr/local/share/emacs/site-lisp/libidn
==> Summary
🍺  /usr/local/Cellar/libidn/1.35: 72 files, 1.4MB
==> Installing inetutils
==> Downloading https://homebrew.bintray.com/bottles/inetutils-1.9.4_1.mojave.bottle.1.tar.gz
######################################################################## 100.0%
==> Pouring inetutils-1.9.4_1.mojave.bottle.1.tar.gz
==> Caveats
The following commands have been installed with the prefix 'g'.

    dnsdomainname
    ftp
    rcp
    rexec
    rlogin
    rsh
    telnet

If you really need to use these commands with their normal names, you
can add a "gnubin" directory to your PATH from your bashrc like:

    PATH="/usr/local/opt/inetutils/libexec/gnubin:$PATH"

Additionally, you can access their man pages with normal names if you add
the "gnuman" directory to your MANPATH from your bashrc as well:

    MANPATH="/usr/local/opt/inetutils/libexec/gnuman:$MANPATH"
==> Summary
🍺  /usr/local/Cellar/inetutils/1.9.4_1: 107 files, 2.6MB
==> Caveats
==> libidn
Emacs Lisp files have been installed to:
  /usr/local/share/emacs/site-lisp/libidn
==> inetutils
The following commands have been installed with the prefix 'g'.

    dnsdomainname
    ftp
    rcp
    rexec
    rlogin
    rsh
    telnet

If you really need to use these commands with their normal names, you
can add a "gnubin" directory to your PATH from your bashrc like:

    PATH="/usr/local/opt/inetutils/libexec/gnubin:$PATH"

Additionally, you can access their man pages with normal names if you add
the "gnuman" directory to your MANPATH from your bashrc as well:

    MANPATH="/usr/local/opt/inetutils/libexec/gnuman:$MANPATH"