file.lock.codes
Description of retrieval/update locks.
Description
description of retrieval/update locks.
Attributes 5 and 6 of file-defining items can contain retrieval and update lock codes respectively. These codes are used to restrict access to certain data files and master dictionaries. Lock codes are sets of characters used as codes. Multiple lock codes are separated by value marks. The first lock code (retrieval or update) in an md or file dictionary must be matched in attribute 6 (key) of the user's item in the users file to allow access to the file or md. If the lock code does not match, access is denied.
Locks can be placed at any file pointer level, system, master dictionary, or dictionary. The system pointer controls access to a master dicitonary; the master dicitonary pointer controls a file dictionary, and a file dictionary pointer controls the data file.
Example
1) In this example, a company has four departments; finance, admin, mis, and
ops. Each department is maintained in a separate master dictionary. Users
remain attached to a specific master dicitonary, but must be prevented from
'q-pointing' or using path names to access files on any other master
dicitonary.
The following are the locks as they appear in the system-level d-pointers and
the user definitions:
In the 'mds' file:
id: finance.mstr admin.mstr mis.mstr ops.mstr
001 d d d d
002 67889 786554 45000 23007
003 11 27 13 11
004
005 finance admin mis ops
006 finance admin mis ops
007
008
009 l l l l
010 10 10 10 10
The following are a few of the users and their locks 'keys'.
user: toms glendaj sama carlak gandalf
006(keys) admin finance mis ops admin]mis]ops
Every user is restricted the those files found on the local master dictionary
except for 'gandalf'. He can access files on 3 of the four master
dictionaries.
2) Update and retrieval locks can be set for specific files. For this example,
two files on the 'admin' account must be restricted. The files are
called, 'payroll' and 'reviews'. A new category of
'supervisor' is added. 'supervisor' files are only
accessable by users with this key regardless of the host master dicitoinary.
On the 'admin' account, these pointers define the dictionaries of the
files:
id: payroll reviews
001 d d
002 56678 344567
003 23 13
004
005 supervisor supervisor
006 supervisor supervisor
007
008
009 l l
010 10 10
'gandalf' is now a supervisor:
user: gandalf
006(keys) admin]mis]ops]supervisor
Now, 'gandalf' can retrieve 'payroll' and
'reviews' but 'toms' is still restricted.
See Also
User Comments
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