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1991-09-02
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C H K S U M Ver. 4.0
(C)1989,1990,1991 Scanlon Enterprises
CHKSUM is a small utility, which can serve as a basic virus
detection system. When first receiving a program use CHKSUM to
get the start check sum. Then verify a match on a regular basis.
Syntax : CHKSUM fname chksum /R
Where : 'fname' is the name of the file to check
'chksum' is a value to compare resulting sum with
'/R' allows redirection
There are no defaults, and a file must be specified.
ERRORLEVELS: 0FF (255) Program Problem (call Author)
3 File not found
2 File name missing
1 Check sum does NOT match
0 OK
EXAMPLES:
CHKSUM fname
Displays the check sum of file 'fname'.
CHKSUM fname 1500
Returns an errorcode of zero if the check sum for 'fname' is
equal to 1500, if not errorlevel is 1.
CHKSUM fname /R
Displays the check sum of a file, but allows redirection to any
device, such as the printer or file.
Page 1 of 3
A use way to use this utility is to get the check sum of a file
and log the check sum. Next make a batch which matches the logged
checksum against the actual.
EXAMPLE:
Get the check sum for COMMAND.COM
CHKSUM COMMAND.COM
Result is 2536, make a batch file using this value
COPY CON CKCMDCOM.BAT
CHKSUM COMMAND.COM 2546
IF ERRORLEVEL 1 GOTO FAIL
GOTO XIT
:FAIL
ECHO COMMAND.COM has been tampered with
:XIT
^Z
When run, the batch file will only display the message if
COMMAND.COM does NOT match the check sum as entered.
The above is only an example, your version of COMMAND.COM will be
different.
*** NOTE *** check sums are in HEX, thus a value of 25A0 would be
a typical value returned. IE... Characters displayed will range
from 0 thru 9 and A thru F !
For additional usage and information on using these utilities see
the file SEBFU.DOC or BATUT.DOC.
Page 2 of 3
C H K S U M Ver. 4.0
(C)1989,1990,1991 Scanlon Enterprises
O R D E R F O R M
CHKSUM registration ..................................... $1.50
What you get :
Unlimited usage of CHKSUM, and phone or write in support. You
will also be placed on our mailing list for future updates and
new products.
We are offering this utility seperate from SEBFU as a favor to
users who do NOT wish to use many of the SEBFU utilities.
This utility is automatically registered to you when you register
SEBFU as a product (see REG.DOC). Registering SEBFU as a product
is a better bargin, as each utility will cost less than $ .25
each.
Vendors:
You may distribute CHKSUM seperately, provided this document is
distributed as well. Any reasonable fee may be charged.
Send your order to : SCANLON ENTERPRISES
38354 17TH ST E.
PALMDALE, CA 93550