get_arg () {
    case "${#ARGSTR}" in
	0) test -n "$1" && logger "$1" && return 0 || { logger "--> -${OPTSTR} argument ?" >&2; return 1; } ;;
	*) logger "$ARGSTR"; return 2;;
    esac
}

 
while :; do 
    case "$#" in 0) break; esac; OPTSTR="$1" 
    case "$OPTSTR" in --) break   ;; 
             --flag_1) OPTSTR=-f1 ;;
             --flag_2) OPTSTR=-f2 ;;
             --flag_3) OPTSTR=-f3 ;;
           --optarg_1) OPTSTR=-o1 ;;
           --optarg_2) OPTSTR=-o2 ;;
    esac 
    case "$OPTSTR" in 
           -*) OPTSTR="${OPTSTR#-}"
               while :; do 
                     case "${#OPTSTR}" in 0) break; esac 
                     ARGSTR="${OPTSTR#?}"; OPTSTR="${OPTSTR%${ARGSTR}}"
                     case "$OPTSTR" in 
                                 o1) OPTARG="$(get_arg "$2")" && shift; case "$?" in 1) exit 65; esac 
                                     logger "-o1/--optarg_1 argument  is $OPTARG";;
                                 o2) OPTARG="$(get_arg "$2")" && shift; case "$?" in 1) exit 65; esac
                                     logger "-o2/--optarg_2 argument  is $OPTARG";;
                                 f1) logger "FLAG_1 is set";;  
                                 f2) logger "FLAG_2 is set";;
                                 f3) logger "FLAG_3 is set";;
                                  *) logger "--> unrecognized option -${OPTSTR}" >&2 && exit 65 ;; 
                     esac 
                     case "$OPTSTR" in o1*|o2*) break; esac
                     OPTSTR="$ARGSTR"
               done 
    esac 
    shift 
done