12.8. The Floating Clock Prompt

#!/bin/bash

#   Rewrite of "clock" using tput

function prompt_command {
#  prompt_x is where to position the cursor to write the clock
let prompt_x=$(tput cols)-6
#  Move up one; not sure why we need to do this, but without this, I always
#  got an extra blank line between prompts
tput cuu1
tput sc
tput cup 0 ${prompt_x}
tput setaf 4 ; tput bold
echo -n "["
tput setaf 1
echo -n "$(date +%H%M)"
tput setaf 4 ; tput bold
echo -n "]"
tput rc
}

PROMPT_COMMAND=prompt_command

function clockt {
local       BLUE="\[$(tput setaf 4 ; tput bold)\]"
local  LIGHT_RED="\[$(tput setaf 1 ; tput bold)\]"
local      WHITE="\[$(tput setaf 7 ; tput bold)\]"
local  NO_COLOUR="\[$(tput sgr0)\]"
case $TERM in
    xterm*|rxvt*)
        TITLEBAR='\[\033]0;\u@\h:\w\007\]'
        ;;
    *)
        TITLEBAR=""
        ;;
esac

PS1="${TITLEBAR}\
$BLUE[$LIGHT_RED\u@\h:\w$BLUE]\
$WHITE\$$NO_COLOUR "
PS2='> '
PS4='+ '
}