Fantastic , that was new to be , I thought of getting rid of the the "disk write" happening while out putting it in to a file.

sed -n "$begin, $end" $logfile >engines
exec < engines
while read line
do
# array insert
done

Thankyou very much , I am so used t bash such that , ksh is not easy for me to use now. It does not ahve the "auto completion when we type something and the the <tab> key stroke