highest_getopts.sh

order=''
count=5
outfile=''
usage="USAGE: $0 [-h|-l] [-n count] [-o outfile] filename"

while getopts ":hln:o:" opt; do
	case $opt in
		h ) ;;
		l ) order='-r'
			;;
		n ) if [[ -n $(echo "$OPTARG" | grep '^[1-9]$') ]]; then
			count=$OPTARG
		    else
			echo "Invalid count value"
			echo $usage
			exit 1
		    fi
		    ;;
		o ) if [[ -n $(echo "$OPTARG" | grep '^[a-zA-Z.]*$') ]]; then
			outfile=$OPTARG
		    else
			echo "Outfile should contain only uppercase, lowercase letter or dots"
			echo $usage
			exit 1
		    fi
		    ;;
		\? ) echo "Invalid option"
		     echo $usage
			exit 1
	esac
done
shift $(($OPTIND -1))
filename=${1:?Please enter the filename}
result=$(sort -n $order $filename | tail -$count)
if [ -n "$outfile" ]; then
	echo "$result" > $outfile
else
	echo "$result"
fi