#!/bin/bash
output=''
for i in {1..4}
do
output=$output"Happy birthday "
if [ $i -eq 3 ]
then
output=$output"dear Midnight Caller $1\n"
else
output=$output"to you\n"
fi
done
echo -e $output
Standard input is empty
Happy birthday to you Happy birthday to you Happy birthday dear Midnight Caller Happy birthday to you