#!/bin/sh
RPTSTR1="bottles of beer" 
RPTSTR2="on the wall"
RPTSTR3="bottle of beer"
REFRAIN="Take one down, pass it around"
I=0
printf "How many bottles? :"
read I
while [ $I -ge 1 ] 
do 
   if [ $I -eq 1 ]; then
      echo $I $RPTSTR3 $RPTSTR2, $I $RPTSTR3!
   else
      echo $I $RPTSTR1 $RPTSTR2, $I $RPTSTR1!
   fi
   echo $REFRAIN,
   I=`expr $I - 1`
   if [ $I -eq 1 ]; then
      echo "$I $RPTSTR3 $RPTSTR2.\n"
   else
      echo "$I $RPTSTR1 $RPTSTR2.\n"
   fi
done