Process single character command line arguments

options.sh

USAGE=`printf "Usage: %s [-a] text\n  -a : Do A" $(basename $0)`

# Get the options
aflag=
while getopts 'a' OPTION; do
	case $OPTION in
	a)	aflag=1
		;;
	?)	echo "$USAGE"
		exit 1
		;;
	esac
done
shift $(($OPTIND - 1))

# Check for additional options
if [ -z "$1" -o ${#*} -ne 1 ]; then
	echo "$USAGE"
	exit 1
fi

# Store the text option
text="$1"

# Do A
if [ -z "$aflag" ]; then
	echo "Do A"
fi