d L o c k & d U n L o c k



by


Joseph L. Cousins




Sierra Consultants
11700 Old Columbia Pike
Suite 1119
Silver Spring, MD 20904
(301) 680-9625

+------------------------------------------------------------------+
: Shareware :
: :
: You are encouraged to copy freely and share with others copies :
: of this program (unmodified). If you make the decision to use :
: this program, support the Shareware concept by becoming a user :
: who has registered this product. We thank you for your support. :
+------------------------------------------------------------------+


























dLock & dUnLock
by
Joseph L. Cousins


What are dLock and dUnLock ?
============================


They are small programs that can be executed from dBASE IV to LOCK and
UNLOCK databases and their associated MEMO files if they exist.


dLock and dUnLock were written to allow dBASE IV users and programmers
the ability to protect their valuable databases from accidental
deletion.


How do they work ?
==================

dLock works by finding the file passed to it on the command line and
performing two separate operations:

1. Set bit 5 to true in the first byte of the dBASE IV header
of the database. This indicates to dBASE IV that the
database is READ-ONLY.

2. Set the READ-ONLY bit in the attribute word of the selected
database. Set the READ-ONLY bit in the attribute word of
the associated MEMO file if found. Setting these bits will
cause DOS to refuse to delete these files if requested.



How do I execute them from dBASE IV ?
=====================================


Use the (!) character or the command (RUN) to proceed the request:

! dlock mybase.dbf

or

RUN dlock mybase.dbf




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Copyright (c) by Sierra Consultants All Rights Reserved















dLock & dUnLock
by
Joseph L. Cousins



dLock will locate the database by searching first the local directory
and then searching the path which it finds in the environment. It
then dLocks the files it found.



The dUnLock program works in the reverse manner as dLock. It searches
for the indicated files and then dUnLocks them.


The dLock and dUnLock programs may be executed from compiled dBASE IV
code.




If you use these programs to protect your data then you should
consider sending the registration amount or send me what you think the
programs are worth to you. Consider that they are capable of
preventing the loss of data which may or may not be replaceable.

If you are a software creator (programmer) who wishes to include these
programs in with your applications please send me $50.00 and I will
send you a version of the programs that has no copyright output and I
will include the source code if you ask. Consider again how easy your
customers will feel when you can guarantee them that their data will
not be deleted or erased by accidental fingers. Consider that even if
you protect the database from dBASE IV by using the PROTECT feature
the database can still be deleted from the DOS command line !!















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Copyright (c) by Sierra Consultants All Rights Reserved















dLock & dUnLock
by
Joseph L. Cousins

Registration Form

Name: _________________________________________

Address:______________________________________________

______________________________________________

City: __________________________ State:____ Zip:________________

Phone: (_____) ______-__________

DOS Version: ________________

Machine Type [ ] True IBM or [ ] Clone
[ ] PC [ ] 5 1/4 [ ] 3 1/2
[ ] XT [ ] 5 1/4 [ ] 3 1/2
[ ] AT [ ] 5 1/4 [ ] 3 1/2
[ ] PS2 [ ] 5 1/4 [ ] 3 1/2
[ ] 386 [ ] 5 1/4 [ ] 3 1/2

Printer Type [ ] HP Laser
[ ] IBM Graphics compatible
[ ] Epson
[ ] Other_________________

Would you like to receive the latest version of dLock & dUnLock ?

[] Yes [] NO (If YES see $5.00 below) Disk Type [] 5 1/4 [] 3 1/2


dLock & dUnLock Registration is $ 15.00 (no tax). If you are
requesting the latest version then include an additional $5.00.
Please send your check or money order to:

Sierra Consultants
11700 Old Columbia Pike
Suite 1119
Silver Spring, MD 20904-2579
(301) 680-0763






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Copyright (c) by Sierra Consultants All Rights Reserved