A nerdy Christmas greeting script [original post: http://questionmark.blogsome.com/2008/12/24/nerdy-christmas-take-2/ ]

greet-xmas.sh

#!/bin/bash

#lights_off
#
#          *==<
#           /\
#          /  \
#         / @  \
#        /      \
#       / @    @ \
#           ||
#
#       NERDY CHRISTMAS
#       AND
#       GEEKY NEW YEAR!
#

#lights_on
#
#          *==<
#           /\
#          / *\
#         / @  \
#        / *  * \
#       / @  * @ \
#           ||
#
#       NERDY CHRISTMAS
#       AND
#       GEEKY NEW YEAR!
#

frows=14
stime=1

# Ensure `tput` is available
if ! command -v tput &>/dev/null; then
    alias tput="clear"
fi

display() {
    tput cup 0 0
    grep -A"$frows" "#$1" "$0" | tail -n"$frows" | sed 's/#/ /'
}

animation() {
    display lights_off && sleep "$stime"
    display lights_on && sleep "$stime"
}

clear
yes | while read -r _; do
    animation
done