BitMiracle.LibTiff.Classic.Tiff.getMode C# (CSharp) Method

        private static int getMode(string mode, string module, out FileMode m, out FileAccess a)
        {
            m = 0;
            a = 0;
            int tiffMode = -1;

            if (mode.Length == 0)
                return tiffMode;

            switch (mode[0])
            {
                case 'r':
                    m = FileMode.Open;
                    a = FileAccess.Read;
                    tiffMode = O_RDONLY;
                    if (mode.Length > 1 && mode[1] == '+')
                    {
                        a = FileAccess.ReadWrite;
                        tiffMode = O_RDWR;
                    }
                    break;

                case 'w':
                    m = FileMode.Create;
                    a = FileAccess.ReadWrite;
                    tiffMode = O_RDWR | O_CREAT | O_TRUNC;
                    break;

                case 'a':
                    m = FileMode.Open;
                    a = FileAccess.ReadWrite;
                    tiffMode = O_RDWR | O_CREAT;
                    break;

                default:
                    ErrorExt(null, 0, module, "\"{0}\": Bad mode", mode);
                    break;
            }

            return tiffMode;
        }