I use the terminal every day and I have spent a lot of time customising its configuration, particularly the default prompt, to my liking.
Today, I will show you how to customise your default prompt, or PS1. Before I show you my spartan configuration, let me explain. I am a minimalist, so I do not see the point of having a long PS1 that shows a multitude of system information when the core *nix utils (/bin) can tell you that anyway.
Note: My terminal is rxvt-unicode, my shell is zsh, and I often run all my cli apps within GNU screen.
PS1="$(print '%{\e[1;31m%}%1%{\e[0m%} %{\e[1;32m%}%B%#%b%{\e[0m%} %(?..(%?%)) %_ \ek\e\\')"
Produces: ~ %
Explanation: The entire PS1 expression is placed within a print command so my shell outputs a “null title-escape-sequence (<esc>k<esc>\) as a part of the prompt.” GNU screen will then use the title-escape-sequence when naming the window (normally changed with C-a A).
%{\e[1;31m%}
– light red
%1
– trailing component of $PWD
%{\e[0m%}
– resets the color
%{\e[1;32m%}
– light green
%B
– start boldface mode
%#
– prints a # if I am a superuser (root) or a % if I am not.
%b
– end boldface mode
%{\e[0m%}
– resets the color
%(?..(%?%))
– takes advantage of zsh’s ternary expressions, which picks different strings depending on a test. In this case, a message is displayed only if the exit code is not zero.
%_
: status of the parser (i.e. if, for, then, while)
\ek\e\\
– the title-escape-sequence for GNU screen
Other common variables you can use include:
%h
– history entry number
%m
– current hostname (up to any dot)
%n
– shows username
%D
– the date in yy-mm-dd format
See “zsh: Prompt Expansion” for the definitive list of zsh prompt sequences.
A list of “colour equivalences:”
Black 0;30 Dark Gray 1;30
Blue 0;34 Light Blue 1;34
Green 0;32 Light Green 1;32
Cyan 0;36 Light Cyan 1;36
Red 0;31 Light Red 1;31
Purple 0;35 Light Purple 1;35
Brown 0;33 Yellow 1;33
Light Gray 0;37 White 1;37
Using a handy script I got from the bash manual, here is a picture of my current color scheme (zenburn):
