https://www.technoduet.com/a-simple-way-to-connect-to-remote-ftp-sever-on-mac/macos
$ ssh root@example.com
http://osxdaily.com/2017/04/28/howto-ssh-client-mac/app
http://osxdaily.com/2016/08/16/enable-ssh-mac-command-line/ssh
https://mediatemple.net/community/products/dv/204405144/using-ssh-in-terminal.app-(mac-os-x)post
how to connect sftp from macosui
http://osxdaily.com/2011/02/07/ftp-from-mac/?relatedposts_hit=1&relatedposts_origin=64173&relatedposts_position=2.net
http://osxdaily.com/2011/09/30/remote-login-ssh-server-mac-os-x/
http://osxdaily.com/2011/09/29/start-an-ftp-or-sftp-server-in-mac-os-x-lion/
https://apple.stackexchange.com/questions/280662/connect-to-remote-server-with-macos-sierra-through-sftpcode
https://www.ssh.com/ssh/putty/mac/server
https://accc.uic.edu/answer/how-do-i-use-ssh-and-sftp-mac-os-xblog