special-pattern.sh

#!/bin/bash

MAX_NO=0

echo -n "Enter Number between (5 to 9) : "
read MAX_NO

if ! [ $MAX_NO -ge 5 -a $MAX_NO -le 9 ]; then
	echo "WTF... I ask to enter number between 5 and 9, Try Again"
	exit 1
fi

clear

for ((i = 1; i <= MAX_NO; i++)); do
	for ((s = MAX_NO; s >= i; s--)); do
		echo -n " "
	done
	for ((j = 1; j <= i; j++)); do
		echo -n " ."
	done
	echo ""
done
###### Second stage ######################
for ((i = MAX_NO; i >= 1; i--)); do
	for ((s = i; s <= MAX_NO; s++)); do
		echo -n " "
	done
	for ((j = 1; j <= i; j++)); do
		echo -n " ."
	done
	echo ""
done

echo -e "\n\n\t\t\t Whenever you need help, Tecmint.com is always there"