ascii flag

Would like an ascii flag which avoids using graphic characters on output.  On the Windows tree command this is the /a flag.

```
C:\>tree  /a \Windows\Web
Folder PATH listing for volume OS
Volume serial number is 000000E1 E0D7:B297
C:\WINDOWS\WEB
+---4K
|   \---Wallpaper
|       \---Windows
+---Screen
\---Wallpaper
    +---Theme1
    +---Theme2
    \---Windows
```