sshd port change
--

shell
--
how to change default shell

which bash

chsh

csh
--
https://en.wikipedia.org/wiki/C_shell
cmd line editing: search for 'String Editing (Colon) Operators'
https://www.cs.ait.ac.th/~on/O/oreilly/unix/upt/ch09_06.htm

.cshrc
prompt
alias
 s sudo
alias tmux      tmux ls
alias tmuxatts0 /usr/local/bin/tmux attach-session -t 0

PATH
env