2D Bash version of the Pipes screensaver.

pipes

#!/bin/bash
declare -i  f=75 s=13 r=2000 t=0 c=1 n=0 l=0
declare -ir w=$(tput cols) h=$(tput lines)
declare -i  x=$((w/2)) y=$((h/2))
declare -ar v=(	[00]="\x83" [01]="\x8f" [03]="\x93"
		[10]="\x9b" [11]="\x81" [12]="\x93"
		[21]="\x97" [22]="\x83" [23]="\x9b"
		[30]="\x97" [32]="\x8f" [33]="\x81" )

OPTIND=1
while getopts "f:s:r:h" arg; do
	case $arg in
	f)	((f=($OPTARG>19 && $OPTARG<101)?$OPTARG:$f));;
	s)	((s=($OPTARG>4  && $OPTARG<16 )?$OPTARG:$s));;
	r)	((r=($OPTARG>0)?$OPTARG:$r));;
	h)	echo -e "Usage: pipes [OPTION]..."
		echo -e "Animated pipes terminal screensaver.\n"
		echo -e "  -f [20-100]\tframerate (D=75)."
		echo -e "  -s [5-15]\tprobability of a straight fitting (D=13)."
		echo -e "  -r LIMIT\treset after x characters (D=2000)."
		echo -e "  -h\t\thelp (this screen).\n"
		exit 0;;
	esac
done

tput smcup
tput reset
tput civis
while ! read -t0.0$((1000/$f)) -n1; do
	# New position:
	(($l%2))    && ((x+=($l==1)?1:-1))
	((!($l%2))) && ((y+=($l==2)?1:-1))

	# Loop on edges (change color on loop):
	((c=($x>$w || $x<0 || $y>$h || $y<0)?($RANDOM%7-1):$c))
	((x=($x>$w)?0:(($x<0)?$w:$x)))
	((y=($y>$h)?0:(($y<0)?$h:$y)))

	# New random direction:
	((n=$RANDOM%$s-1))
	((n=($n>1||$n==0)?$l:$l+$n))
	((n=($n<0)?3:$n%4))

	# Print:
	tput cup $y $x
	echo -ne "\033[1;3${c}m\xe2\x94${v[$l$n]}"
	(($t>$r)) && tput reset && tput civis && t=0 || ((t++))
	l=$n
done
tput rmcup

License: Public Domain