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OBLIT.DOC
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Text File
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1993-08-06
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4KB
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101 lines
OBLIT.DOC - v1.1
(C)1993 Tolgathian Software
Hello!
This program is for you security minded people out there. It will
completely and irretrievably destroy the content of ANY file. It
then deletes it for good measure. As most of you know, when you
delete a file in MS-DOS, all it does is remove it from the File
Allocation Table. The file is still there, but it is just removed
from the MS-DOS "do not use this space" list. It can easily be
undeleted with the DOS command UNDELETE. If someone was to undelete
a file after you have used OBLIT on it, however, it will be
completely full of zeros (blank) if they try and look at it.
= Legalus Stayvus Offus ad Legalus Nauseum =
Tolgathian Software hereby places this program and it's related
documentation into the Public Domain as long as this document file
remains with it and both remain unaltered. It may be archived and
freely distributed across, through and in any medium. It may be
distributed by commercial operations as long as no charge is made
for the software - only a reasonable medium/processing charge may
apply. Tolgathian Software and anyone related to it (i.e.: it's
employees, members, and owners) provide this software as is, and
no garauntee is made for it's proper operation and fitness for any
purpose. The user understands and agrees that the user will not
hold Tolgathian Software, it's employees, members, or owners
responsible for any direct, incidental, related, consequential,
or otherwise remotely conceived damages as the result of it's use
or misuse.
Sorry to bore you with that stuff, but good heavens! People will
sue the Mayor if they fall and hurt themselves while doing a
handstand on a skateboard going downhill on a gravel sidewalk
backwards with no helmet at rush-hour blindfolded. And some fool
lawyer that should know better will help them do it!
("Doctor! It hurts when I do this!" "Well, don't do it."
"You Quack! I'm gonna sue you from here 'til Sunday!")
= Internalus Workus =
This is how it works. OBLIT looks at the file and sees how many
bytes long it is. It then writes six different byte-long bit patterns
for the length of the file. These patterns are:
10101010
01010101
11110000
00001111
11111111
00000000
As you can see, the last pattern is all zeros. This is what the
file is left containing before being deleted.
Be sure that you want to destroy the file before you do so, as
unlike a simple MS-DOS delete, there is NO way to bring this file
back. It is gone forever. Period. Also be aware that many programs,
especially word processors and text editors, create a .BAK version
of the file. Make sure that if you are trying to OBLIT a file that
you OBLIT other copies of it as well! For example, suppose I have
a file called PERSONAL.TXT and I edit it with my favorite text
editor. Every time I do so, the editor makes a PERSONAL.BAK copy of
the file. If I decide to OBLIT the file PERSONAL.TXT, I must also
OBLIT the file PERSONAL.BAK, otherwise someone could read it.
A simple way to look for multiple copies of a file in a directory
is to do a DIR command on the file, without the extension:
DIR PERSONAL will reveal the files PERSONAL.TXT, PERSONAL.BAK,
and PERSONAL.DOC.
USAGE:
OBLIT [?]
Items in brackets are optional.
? -include this on the command line for the
help screen.
OBLIT warns you what it does, and asks for a filename. You must
enter a filename, and the filename can include a path. Suppose I
wanted to OBLIT a file called PERSONAL.TXT on the B: drive in the
directory DOCS. I would type: B:\DOCS\PERSONAL.TXT
Note that OBLIT doe NOT accept wildcards (*,?) in the filename.
This protects against accidental catastrophic obliterations.
You must run OBLIT for each file you want obliterated.
Also note that you can not OBLIT an already deleted file. You
must undelete it first and THEN OBLIT it.
Next, OBLIT warns you again that the file will be GONE when it
is done. You must type YES in capital letters for OBLIT to work.
Any other response will abort the operation with an OK message.
If you type YES, then moments later you can rest assured the file
is absolutely obliterated.
Good Luck!
Tolgathian Software - purveyors of fine no frills utilities.