#!//bin/bash
## loop the number of times given by first arg $1   - bash version

i=1

while [[ $i -le "$1" ]] ; do
	echo "Iteration $i (bash)"
	i=$(( $i + 1 ))   ## $ not needed inside:  $(( i + 1 )) is fine.
done


#!/bin/sh
## loop the number of times given by first arg $1   - sh and bash version  

i=1

while [ $i -le "$1" ] ; do
	echo "Iteration $i (sh)"
	i=`expr "$i" + 1`   ## Spaces required around the + and $ required.
done