Bash Prompt Customization
Sep 14th, 2009 by pixel

Here are the backslash-escape special characters that have meaning to bash:
 \a     an ASCII bell character (07)
 \d     the date  in  "Weekday  Month  Date"  format
        (e.g., "Tue May 26")
 \e     an ASCII escape character (033)
 \h     the hostname up to the first `.'
 \H     the hostname
 \j     the  number of jobs currently managed by the shell
 \l     the basename of the shell's terminal device name
 \n     newline
 \r     carriage return
 \s     the  name  of  the shell, the basename of $0
        (the portion following the final slash)
 \t     the current time in 24-hour HH:MM:SS format
 \T     the current time in 12-hour HH:MM:SS format
 \@     the current time in 12-hour am/pm format
 \u     the username of the current user
 \v     the version of bash (e.g., 2.00)
 \V     the release of bash,  version  +  patchlevel
        (e.g., 2.00.0)
 \w     the current working directory
 \W     the  basename  of the current working direcory
 \!     the history number of this command
 \#     the command number of this command
 \$     if the effective UID is 0, a #, otherwise a $
 \nnn   the character corresponding to the octal number nnn
 \\     a backslash
 \[     begin a sequence of non-printing characters,
        which could be used to embed a terminal control
        sequence into the prompt
 \]     end a sequence of non-printing characters

Colours In Bash:
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

Here is an example borrowed from the Bash-Prompt-HOWTO:

    PS1="\[\033[1;34m\][\$(date +%H%M)][\u@\h:\w]$\[\033[0m\]

This turns the text blue, displays the time in brackets (very useful for not losing track of time while working), and displays the user name, host, and current directory enclosed in brackets. The "\[\033[0m\]" following the $ returns the colour to the previous foreground colour.