IMPLEMENTATION MODULE CmdLineArgs;

FROM VMSRTL IMPORT Lib$Get_Foreign;

VAR
    argv : ARRAY [1..80] OF CHAR;
    i, nextarg : INTEGER;
    cmdlen     : INTEGER;
    stopchar   : CHAR;
    
PROCEDURE Getarg(
    VAR arg : ARRAY OF CHAR (* out *) ) : BOOLEAN;
    (*
    Returns the next arg from the argv. If no more arg's, the procedure
    returns false.
    *)
    BEGIN
        IF nextarg = 0 THEN   (* get the cmd line *)
            i := Lib$Get_Foreign( argv, "enter args: ", cmdlen );
            IF i # 1 THEN
                RETURN FALSE
            END;
            nextarg := 1  (* point to first loc in argv *)
        END;
    
        IF nextarg >= cmdlen THEN
            arg[0] := 0C;   (* no more args *)
            RETURN FALSE
        END;
    
        i := 0;
        stopchar := " ";
        WHILE ( i <= HIGH( arg ) ) AND ( nextarg <= cmdlen ) AND
              ( argv[ nextarg ] # stopchar ) DO
              arg[i] := argv[ nextarg ];
              INC( i );
              INC( nextarg )
        END;
        arg[ i ] := 0C;
        
        (* move over to the next arg in argv *)
        IF nextarg < cmdlen THEN
            IF argv[ nextarg ] = " " THEN
                WHILE ( argv[ nextarg ] = " " ) AND ( nextarg <= cmdlen ) DO
                    INC( nextarg )
                END
            END
        END;
        RETURN TRUE
    END Getarg;

(* Initialization code *)
BEGIN
    nextarg := 0
END CmdLineArgs.