[转]shell getopts用法

function usage()
{
        [[ ! -z $2 ]] && ( echo "$2"; echo ""; )
        echo "Usage: $(basename $1) vm_image=PATH [-h|--help]"
        echo "-h, --help            Print help and exit"
        echo "    --vm_image=PATH   Path to VM image used in these tests"
}
while getopts 'h-:' optchar; do
        case "$optchar" in
                -)
                case "$OPTARG" in
                        vm_image=*) os_image="${OPTARG#*=}" ;;
                        *) usage $0 echo "Invalid argument '$OPTARG'" && exit 1 ;;
                esac
                ;;
                h) usage $0 && exit 0 ;;
                *) usage $0 "Invalid argument '$optchar'" && exit 1 ;;
        esac
done