   /* All of the options in this arg are valid, so handle them. */
                        p = arg + 1;
                        do {
                            if (*p == 'n')
                                nflag = 0;
                            if (*p == 'e')
                                eflag = '\\';
                        } while (*++p); 
                        ```
                        [source](https://git.busybox.net/busybox/tree/coreutils/echo.c?h=1_36_stable#n287)
                    </script