Shell Programming and Scripting

#!/bin/bash
#
# Flash and fade for a Macbook Pro OSX 2.7.5 Terminal...
# A DEMO to show how to give an AT A GLANCE, and, audible warning of impending doom in a shell script.
# It is for something like an analogue Data Logger input say from an Arduino analogue source.
#
# It may well work on other Linux and Unix like machines but is untested and uses the "tput" command
# to hide and unhide the terminal cursor. The command "setterm" is commented out and could be used
# in place of the above depending on the *NIX flavour...
#
# Written in such a way that anyone can understand how it works.
#
# It starts with 10 cycles of grey/gray scale fading on a black background without any beeps then next
# 5 yellow warning flashes with a beep every full flash and finally 5 FULL screen red flashes with beeps
# on every ON and OFF state.
#
# Clear a screen to white on black...
printf "\033[0;37;40m"
clear
printf "\n           Flash and fade for a default Macbook Pro OSX 2.7.5 Terminal.\n"
# Turn the cursor off...
#setterm -cursor off
tput civis
# Fade on and off 10 times, grey/gray scales on black.
for fade in $(seq 1 10)
do
	printf "\033[12;23f\033[1;30;40mFading using four _shades_ of grey...\033[0m"
	sleep 0.1
	printf "\033[12;23f\033[1;90;40mFading using four _shades_ of grey...\033[0m"
	sleep 0.1
	printf "\033[12;23f\033[1;37;40mFading using four _shades_ of grey...\033[0m"
	sleep 0.1
	printf "\033[12;23f\033[1;97;40mFading using four _shades_ of grey...\033[0m"
	sleep 0.1
	printf "\033[12;23f\033[1;37;40mFading using four _shades_ of grey...\033[0m"
	sleep 0.1
	printf "\033[12;23f\033[1;90;40mFading using four _shades_ of grey...\033[0m"
	sleep 0.1
done
# Over-write the above with the same line again but with black foreground and background colo(u)rs.
printf "\033[12;23f\033[1;30;40mFading using four _shades_ of grey...\033[0m"
# Now flash a YELLOW warning line with beeps for 5 times.
for flash in $(seq 1 5)
do
	printf "\033[12;37f\033[0;93;40mWARNING!\033[0m\a"
	sleep 0.5
	printf "\033[12;37f\033[0;30;103mWARNING!\033[0m"
	sleep 0.5
done
# Finally a full window flash with _continuous_ beeps.
for fullflash in $(seq 1 5)
do
	printf "\033[1;91;40m"
	clear
	printf "\033[12;36f\033[1;91;40mDANGER!!!\a"
	sleep 0.5
	printf "\033[0;30;101m"
	clear
	printf "\033[12;36f\033[1;30;101mDANGER!!!\a"
	sleep 0.5
done
# Reset the cursor back on...
#setterm -cursor on
tput cnorm
# Reset the terminal colo(u)rs back to the defaults...
printf "\033[0m"
clear
printf "\n         \$VER: Fade.sh_Version_0.00.10_Public_Domain_2012_B.Walker_G0LCU.\n\n"
# Fade.sh DEMO end...
# Enjoy finding simple solutions to often very difficult problems...