NAME
        GetRexxVar - Gets the value of a variable from a running ARexx program

   SYNOPSIS
        error = GetRexxVar(message,varname,bufpointer)
        D0,A1              A0      A1      (C-only)

        long getrexxvar(struct rexxmsg *,char *,char **);

   FUNCTION
        This function will attempt to extract the value of the symbol
        varname from the ARexx script that sent the message.  When called
        from C, a pointer to the extracted value will be placed in the
        pointer pointed to by bufpointer.  (*bufpointer will be the pointer
        to the value)

        When called from assembly, the pointer will be returned in A1.

        The value string returned *MUST* *NOT* be modified.

        While this function is new in the V37 amiga.lib, it is safe to
        call it in all versions of the operating system.  It is also
        PURE code, thus usable in resident/pure executables.

   NOTE
        This is a stub in amiga.lib.  It is only available via amiga.lib.
        The stub has two labels.  One, _GetRexxVar, takes the arguments
        from the stack.  The other, GetRexxVar, takes the arguments in
        registers.

        This routine does a checkrexxmsg() on the message.

   EXAMPLE

        char    *value;

        /* message is one from arexx */
        if (!GetRexxVar(rxmsg,"TheVar",&value))
        {
                /* The value was gotten and now is pointed to by value */
                printf("Value of TheVar is %sn",value);
        }

   INPUTS
        message         A message gotten from an ARexx script
        varname         The name of the variable to extract
        bufpointer      (For C only) A pointer to a string pointer.

   RESULTS
        error           0 for success, otherwise an error code.
                        (Other codes may exists, these are documented)
                        3  == Insufficient Storage
                        9  == String too long
                        10 == invalid message

        A1              (Assembly only)  Pointer to the string.

   SEE ALSO
        setrexxvar(), checkrexxmsg()