Subj : Beautiful hacks
To   : Bob Worm
From : Ben Collver
Date : Mon Oct 23 2023 10:43:26

  Re: Beautiful hacks
  By: Bob Worm to Ben Collver on Sun Oct 22 2023 22:41:56

BC> This made the file "invisible" in the directory listing.  We used
C> Alt+255 to enter this character at the command prompt.

BW> I've never heard of that one before - did any file with that character
BW> in it turn invisible? How do you turn them back visible if you don't
BW> know the names?

No, that character displays as a space.  So if the filename is only
comprised of that character, it would show up in the directory listing
with the date, file size, etc, but the name would be blank.  If the
name contained other characters, it would look like a file name with a
space in it.

Getting the names is tricky.  In plain DOS it could be done like so:

C:\> dir >lis.txt
C:\> debug lis.txt
-        d 100
....

And keep pressing enter until you get to the end of the listing.

-
0CE8:0680  20 4C 4F 50 48 45 52 2E-42 41 54 0D 0A 4D 45 4E  LOPHER.BAT..MEN
0CE8:0690  55 20 20 20 20 20 49 4E-49 20 20 20 20 20 20 20 U     INI
0CE8:06A0  20 20 20 20 20 20 20 20-20 33 32 34 20 30 36 2D          324 06-
0CE8:06B0  32 32 2D 32 30 32 32 20-20 32 3A 31 35 70 20 4D 22-2022  2:15p M
0CE8:06C0  45 4E 55 2E 49 4E 49 0D-0A FF 20 20 20 20 20 20 ENU.INI...
0CE8:06D0  20 20 20 20 20 20 20 20-20 20 20 20 20 20 20 20
0CE8:06E0  20 20 20 20 20 20 31 30-20 31 30 2D 32 33 2D 32       10 10-23-2
0CE8:06F0  30 32 33 20 20 38 3A 33-32 61 20 FF 0D 0A 20 20 023  8:32a ...
-
0CE8:0700  20 20 39 20 46 69 6C 65-28 73 29 20 20 20 20 20   9 File(s)
0CE8:0710  20 20 20 20 20 20 20 31-30 2C 31 31 31 20 42 79        10,111 By
0CE8:0720  74 65 73 0D 0A 20 20 20-31 36 20 44 69 72 28 73 tes..   16 Dir(s
0CE8:0730  29 20 20 20 20 32 36 39-2C 31 34 34 2C 32 36 30 )    269,144,260
0CE8:0740  2C 36 30 38 20 42 79 74-65 73 20 66 72 65 65 0D ,608 Bytes free.
0CE8:0750  0A C6 C6 C6 7C 00 00 00-00 00 00 C6 00 7C C6 C6 ....|........|..
0CE8:0760  C6 C6 7C 00 00 00 00 00-F6 62 64 60 60 60 62 66 ..|......bd```bf
0CE8:0770  FE 00 00 00 00 00 76 32-34 30 30 30 30 30 78 00 ......v2400000x.

Notice on line 0CE8:06F0 there is the hexadecimal output:

"20 FF 0D 0A"

This shows that the file name is a single hexadecimal character FF,
which is a single non-breaking space.  This method can be used to
display any 8+3 combination of non-breaking spaces.

.