Shell Programming and Scripting

#!/bin/sh
datafile=ABC2008101601.OUT
indfile=ABCIND20081016.1.OUT
waittime=600
starttime=0
while [ $starttime -le $waittime ]
do
 if [ -f $indfile ]
 then
  echo "Indicator file has arrived."
  break
 else
  sleep 10;
  ((starttime=$starttime+10))
  
  echo $starttime
  echo $waittime
  
  if [ $starttime -eq $waittime ]
  then
   echo "Waittime excceded"
   Get_feed_date=`sqlplus -s amit/amit@amit  <<END 
   set feedback off;
   set heading off;
   select to_char(feed_next_dt, 'YYYYMMDD') from FEED where  source_desc='ABC';
   exit;
   END`
   echo $Get_feed_date
   exit 0
  fi
 fi
done

sleep 10;
((starttime=starttime+10))

echo $SHELL

/bin/sh --version

sleeptime=`expr $sleeptime + 10`