bash-2.03$ cat somescript
start=`grep -n "$1" alert_lawp1.log | head -1 |awk -F":" '{print $1}'`
end=`grep -n "$1" alert_lawp1.log | tail -1 |awk -F":" '{print $1"p"}'`
echo "Start line $start";
echo "End line $end";
sed -n $start,$end alert_lawp1.log > newLog

bash-2.03$ cat somescript
start=`grep -n "$1" alert_lawp1.log | head -1 |awk -F":" '{print $1}'`
end=`grep -n "$2" alert_lawp1.log | head -1 |awk -F":" '{print $1"p"}'`
echo "Start line $start";
echo "End line $end";
sed -n $start,$end alert_lawp1.log > newLog
bash-2.03$ somescript "Fri Jun 27" "Sat Jun 28"
Start line 16800
End line 16912p