i-bash/tests/getopts4.sub

aflag=
bflag=

while getopts :ab: name "$@"
do
	case $name in
	a)	aflag=1 ;;
	b)	bflag=1
		bval=$OPTARG;;
	:)	echo $0: error: option \`$OPTARG\' requires an argument
		echo Usage: $0 [-a] [-b value] args
		exit 2;;
	?)	echo $0: error: illegal option character \`$OPTARG\'
		echo Usage: $0 [-a] [-b value] args
		exit 2;;
	esac

done

if [ ! -z "$aflag" ] ; then echo -a specified ; fi
if [ ! -z "$bflag" ] ; then echo -b $bval specified ; fi

if [ "$OPTIND" -gt 1 ]
then
	shift $(( $OPTIND - 1 ))
fi

echo remaining args: "$*"

exit 0