Shell Programming and Scripting

we should do a grep for the trailer record in a file file.out (TRL is searching word)
If the trailer is not found, the script should go to sleep for a period of time to be determined, then do the grep again. This way, the script will stay in a loop and not exit until the entire file has been transmitted to this directory. That will be the internal do loop.Please suggest me to how can i do that in a shell script.
Thanks
Reddi

The main.sh is a dummy script that writes some info to outfile.

team$ cat main.sh
#!/usr/bin/ksh

i=1

while [ $i -le 5 ] ; do

if [ $i -eq 5 ]; then
echo "TRL" >> outfile
else
echo "Line is $i" >> outfile
fi
sleep 10
i=`expr $i + 1`
done

team$

The main.sh will create a file like this ,

team$ cat outfile
Line is 1
Line is 2
Line is 3
Line is 4
TRL
team$


This monitor.sh will look for the TRL in the trailer record of the outfile, until the TRL is found.

team$ cat monitor.sh
#!/usr/bin/ksh


while [ 1 ] ; do

tail -1 outfile 2>/dev/null | grep "TRL" 2>/dev/null 2>&1

if [ $? -eq 0 ]; then
echo "Trailer Record Found"
break
else
echo "Trailer Record Not Found .. Monitoring "
sleep 5
fi


done

team$


team$ main.sh &
[2] 23378
team$ monitor.sh
Trailer Record Not Found .. Monitoring
Trailer Record Not Found .. Monitoring
Trailer Record Not Found .. Monitoring
Trailer Record Not Found .. Monitoring
Trailer Record Not Found .. Monitoring
Trailer Record Not Found .. Monitoring
Trailer Record Not Found .. Monitoring
TRL
Trailer Record Found
team$


Not sure if I understood your need properly,

Thanks Rajesh.I modifiled your scrip according to my result.