DEFINITION MODULE GetOpt ;

FROM SYSTEM IMPORT ADDRESS ;
FROM DynamicStrings IMPORT String ;

CONST
   no_argument = 0 ;
   required_argument = 1 ;
   optional_argument = 2 ;

TYPE
   LongOptions ;
   PtrToInteger = POINTER TO INTEGER ;

(*
   GetOpt - call C getopt and fill in the parameters:
            optarg, optind, opterr and optopt.
*)

PROCEDURE GetOpt (argc: INTEGER; argv: ADDRESS; optstring: String;
                  VAR optarg: String;
                  VAR optind, opterr, optopt: INTEGER) : CHAR ;


(*
   InitLongOptions - creates and returns a LongOptions empty array.
*)

PROCEDURE InitLongOptions () : LongOptions ;


(*
   AddLongOption - appends long option {name, has_arg, flag, val} to the
                   array of options and new long options array is
                   returned.
                   The old array, lo, should no longer be used.

   (from man 3 getopt)
       The meanings of the different fields are:

       name   is the name of the long option.

       has_arg
              is: no_argument (or 0) if the option does not take an
              argument; required_argument (or  1) if the option
              requires an argument; or optional_argument (or 2) if
              the option takes an optional argument.

       flag   specifies how results are returned for a long option.
              If flag is NULL, then getopt_long() returns val.
              (For example, the calling program may set val to the
              equivalent short option character).  Otherwise,
              getopt_long() returns 0, and flag points to a
              variable which is set to val if the option is found,
              but left unchanged if the option is not found.

       val    is the value to return, or to load into the variable
              pointed to by flag.

       The last element of the array must be filled with zeros.
*)

PROCEDURE AddLongOption (lo: LongOptions; index: CARDINAL;
                         name: String; has_arg: INTEGER;
                         VAR flag: INTEGER; val: INTEGER) : LongOptions ;


(*
   KillLongOptions - returns NIL and also frees up memory
                     associated with, lo.
*)

PROCEDURE KillLongOptions (lo: LongOptions) : LongOptions ;


(*
   GetOptLong - works like GetOpt but will accept long options (using
                two dashes).  If the program only accepts long options
                then optstring should be an empty string, not NIL.
*)

PROCEDURE GetOptLong (argc: INTEGER; argv: ADDRESS;
                      optstring: String; longopts: LongOptions;
                      VAR longindex: INTEGER) : INTEGER ;


(*
   GetOptLongOnly - works like GetOptLong except that a single dash
                    can be used for a long option.
*)

PROCEDURE GetOptLongOnly (argc: INTEGER; argv: ADDRESS;
                          optstring: String; longopts: LongOptions;
                          VAR longindex: INTEGER) : INTEGER ;


END GetOpt.