Shell Programming and Scripting

#!/bin/ksh
#Initial Variables
IFILE="$HOME/bday.csv"
OFILE="bday_out"$$
MAILID="abc@xxx.com"
#get today's date & month
DAT=`(date '+%d')`
DAY=`(date '+%a')`
MON=`(date '+%b')`
while IFS=',' read name date day month year
do
set -x
if [ "$date" -eq "$DAT" -a "$day" = "$DAY" -a "$month" = "$MON" ]
set +x
   then echo $name
   fi
done < $IFILE > $OFILE
set -x
if [ -f $OFILE -a -s $OFILE ]
set +x
then
   sed -i '1i The following users celebrate their birthday:\n' $OFILE
   mailx -s "Birthday on: $DAT" $MAILID  < $OFILE
  # \rm $OFILE
   echo "Birthday mail sent"
else
   echo "No birthdays today"
fi