NAME
        ReadArgs - Parse the command line input (V36)

   SYNOPSIS
        result = ReadArgs(template, array, rdargs)
        D0                   D1      D2      D3

        struct rdargs * readargs(strptr, long *, struct rdargs *)

   FUNCTION
        Parses and argument string according to a template.  Normally gets
        the arguments by reading buffered IO from input(), but also can be
        made to parse a string.  MUST be matched by a call to freeargs().

        ReadArgs() parses the commandline according to a template that is
        passed to it.  This specifies the different command-line options and
        their types.  A template consists of a list of options.  Options are
        named in "full" names where possible (for example, "Quick" instead of
        "Q").  Abbreviations can also be specified by using "abbrev=option"
        (for example, "Q=Quick").

        Options in the template are separated by commas.  To get the results
        of ReadArgs(), you examine the array of longwords you passed to it
        (one entry per option in the template).  This array should be cleared
        (or initialized to your default values) before passing to ReadArgs().
        Exactly what is put in a given entry by ReadArgs() depends on the type
        of option.  The default is a string (a sequence of non-whitespace
        characters, or delimited by quotes, which will be stripped by
        ReadArgs()), in which case the entry will be a pointer.

        Options can be followed by modifiers, which specify things such as
        the type of the option.  Modifiers are specified by following the
        option with a '/' and a single character modifier.  Multiple modifiers
        can be specified by using multiple '/'s.  Valid modifiers are:

        /S - Switch.  This is considered a boolean variable, and will be
             set if the option name appears in the command-line.  The entry
             is the boolean (0 for not set, non-zero for set).

        /K - Keyword.  This means that the option will not be filled unless
             the keyword appears.  For example if the template is "Name/K",
             then unless "Name=<string>" or "Name <string>" appears in the
             command line, Name will not be filled.

        /N - Number.  This parameter is considered a decimal number, and will
             be converted by ReadArgs.  If an invalid number is specified,
             an error will be returned.  The entry will be a pointer to the
             longword number (this is how you know if a number was specified).

        /T - Toggle.  This is similar to a switch, but when specified causes
             the boolean value to "toggle".  Similar to /S.

        /A - Required.  This keyword must be given a value during command-line
             processing, or an error is returned.

        /F - Rest of line.  If this is specified, the entire rest of the line
             is taken as the parameter for the option, even if other option
             keywords appear in it.

        /M - Multiple strings.  This means the argument will take any number
             of strings, returning them as an array of strings.  Any arguments
             not considered to be part of another option will be added to this
             option.  Only one /M should be specified in a template.  Example:
             for a template "Dir/M,All/S" the command-line "foo bar all qwe"
             will set the boolean "all", and return an array consisting of
             "foo", "bar", and "qwe".  The entry in the array will be a pointer
             to an array of string pointers, the last of which will be NULL.

             There is an interaction between /M parameters and /A parameters.
             If there are unfilled /A parameters after parsing, it will grab
             strings from the end of a previous /M parameter list to fill the
             /A's.  This is used for things like Copy ("From/A/M,To/A").

        ReadArgs() returns a struct rdargs if it succeeds.  this serves as an
        "anchor" to allow freeargs() to free the associated memory.  you can
        also pass in a struct rdargs to control the operation of readargs()
        (normally you pass NULL for the parameter, and ReadArgs() allocates
        one for you).  This allows providing different sources for the
        arguments, providing your own string buffer space for temporary
        storage, and extended help text.  See <dos/rdargs.h> for more
        information on this.  Note: if you pass in a struct rdargs, you must
        still call freeargs() to release storage that gets attached to it,
        but you are responsible for freeing the rdargs yourself.

        If you pass in a rdargs structure, you must reset (clear or set)
        RDA_Buffer for each new call to rdargs.  the exact behavior if you
        don't do this varies from release to release and case to case; don't
        count on the behavior!

        See BUGS regarding passing in strings.

   INPUTS
        template - formatting string
        array    - array of longwords for results, 1 per template entry
        rdargs   - optional rdargs structure for options.  allocdosobject
                   should be used for allocating them if you pass one in.

   RESULT
        result   - a struct rdargs or null for failure.

   BUGS
        In V36, there were a couple of minor bugs with certain argument
        combinations (/M/N returned strings, /T didn't work, and /K and
        /F interacted).  Also, a template with a /K before any non-switch
        parameter will require the argument name to be given in order for
        line to be accepted (i.e. "parm/K,xyzzy/A" would require
        "xyzzy=xxxxx" in order to work - "xxxxx" would not work).  If you
        need to avoid this for V36, put /K parameters after all non-switch
        parameters.  These problems should be fixed for V37.

        Currently (V37 and before) it requires any strings passed in to have
        newlines at the end of the string.  This may or may not be fixed in
        the future.

   SEE ALSO
        findarg(), readitem(), freeargs(), allocdosobject()