ProfitPress Mega CDROM2 …eeware (MSDOS)(1992)(Eng)/ProfitPress-MegaCDROM2.B6I/MISC/NETWORK/INSFIX.ZIP/README.TXT

Text File | 1992-03-27 | 14.5 KB | 316 lines

                          ---->  INSFIX V1.4  <----

                               March 27, 1992

(C) 1992 ZyBel MicroSystems Inc.  All rights reserved.


1.  Introduction
----------------

This file describes a LAN utility called INSFIX, which was created to solve a
specific problem with a commercial program known as INSMARK*, but which has
many uses in a networked environment.

INSMARK, a popular insurance application, is available in a network ready
version, but only supporting the Novell NOS.  INSMARK is not compatible with
other networks, including LANTASTIC.  ZyBel was able to get INSMARK to
operate perfectly on a LANTASTIC network by writing the INSFIX utility.

Insfix is similar in nature to the DOS APPEND command, but with some
important differences:

1).  INSFIX only occupies 2.4K of memory (as opposed to 10K of memory with
     APPEND if executables are to be included).

2).  INSFIX is removable from memory. APPEND is not.

3).  INSFIX will not redirect FCB calls (APPEND does).  However, programmers
     were discouraged from using DOS FCB file functions after DOS V2.0, and
     thus very few commercial applications do so today.

4).  INSFIX supports two special options that modify the file open access
     modes and/or the share permissions for redirected files.  These options
     can be used to allow a single user application to be converted to multi-
     user LAN operation - depending upon the structure of the application.

NOTE:     ZyBel does NOT support in any way the violation of commercial
          single user software licenses, and the license granted with INSFIX
          specifically prohibits its use in this fashion.  INSFIX can be used
          to permit some types of in-house developed applications to run in a
          multi-user environment, and can be used to correct application
          specific problems with some network-ready (multi-user licensed)
          commercial programs.


A demonstration version of INSFIX is included along with this text file.
This demonstration version is fully functional, but will cease operating
after approximately 200 file redirections.  The symptoms of the DEMO program
stopping operation will be a failure in the application currently running, or
the inability to start a new application which requires INSFIX.  The program
can be removed from memory, and re-loaded as required, for evaluation
purposes.  The demonstration version is called INSDEMO.EXE, and should be
used in place of INSFIX in the application examples discussed in this file.


2.  Insmark
-----------

As mentioned in the introduction, Insmark is a popular program for the
insurance industry providing comprehensive graphics capabilities for
producing insurance illustrations and analysis.

Insmark is available in a network ready version, but only for use with the
Novell NOS.  The multi user version of Insmark is essentially identical to
the single user version - only the installation instructions differ.  Insmark
is loaded in a "shared" directory (one that all users have access to through
the network), and a subset of the files are copied to a private directory
(each user has a private directory).

The Novell MAP command is then used to establish a search path to the shared
directory.  Insmark is actually run from the private directory.  When Insmark
is first started, it requests that the user enter the name of the directory
where Insmark is located.  The user should specify the PRIVATE directory
path.  Insmark will then try to access files in the private directory.  If
the file is a personal data file, it is opened in the private directory.  If
the file is a shared file (program file, overlay etc), it is opened in the
shared directory because of the Novell MAP command.  This is essentially
identical to the DOS APPEND command if the executable option is specified
(/X:on).

Through the above process, Insmark keeps multiple copies of personal files
(each in a private directory), and reads files from a shared data directory.

When trying to configure Insmark on a Lantastic network, the DOS APPEND
command was used in place of the Novell MAP command.  Unfortunately, the DOS
APPEND command does not function with Insmark.  In reality, even if Append
did operate with Insmark, the application would still not operate on a
network.  This is because Insmark opens shared data files in R/W mode, even
if it is only reading information from the file.  As a result, the shared
files cannot be set to Read Only mode, and share violations will occur if
more than one user attempts to read from the same file at the same time.


3.   INSFIX
-----------

The INSFIX utility solves these problems by providing a functional version of
APPEND, but with several special options:

a).  The /X option allows executable calls (load a program) to be redirected
     along with data read/write functions.  This is similar to the APPEND
     /X:ON parameter.

b).  The /S option will modify file OPEN share parameters on REDIRECTED FILE
     OPERATIONS to DENY/NONE.  This means that if a file was not found in the
     specified directory, but is found in a redirected path, the share
     permissions will be changed to DENY/NONE, preventing any share
     violations from occurring.

c).  The /R option will modify any file OPEN requests on REDIRECTED FILE
     OPERATIONS to READ mode.  Since the purpose of INSFIX is to allow shared
     files to be accessed transparently to a DOS application, presumably the
     application will only read data from these files (else file corruption
     could occur). As a result, applications should only open such files in
     READ mode.  Insmark, as an example, still opens these files in R/W mode.
     This option modifies the actual file open command to specify READ mode,
     thus allowing the shared files to be configured as READ/ONLY (using the
     DOS ATTRIB command), and preventing any share violations.

Either of options b) or c) above can be used to prevent share violations in a
networked environment.


The correct syntax for INSFIX is as follows:

INSFIX    PATH1 <PATH2>  ... <PATH10> </X> </R> </S> </U>

where     PATH1          is a DOS path name to which file operations should
                         be redirected if such operations failed in the
                         current directory, or in the specified full path.

          PATH2          is a second DOS path name for redirection (if the
                         file operation was not successful in PATH1).
          ...

          PATH10         up to 10 PATHs may be specified

          /X             Specifies that executable file operations should be
                         redirected along with file open/read/write requests.
                         This allows programs to be run from appended paths,
                         or overlays loaded.

          /R             Specifies that redirected file OPEN functions (file
                         operations that failed in the current directory or
                         the specified full path) should have the access mode
                         changed to READ.

          /S             Specifies that redirected file OPEN functions (file
                         operations that failed in the current directory or
                         the specified full path) should have the share
                         permissions changed to DENY/NONE.

          /U             Will unload INSFIX from memory if possible (if no
                         other TSR programs were loaded after INSFIX that use
                         the same interrupts).


If INSFIX is run without any arguments, the current INSFIX settings are
displayed.  INSFIX may be run at any time to replace the parameters currently
loaded in memory.  This will not load a second copy of INSFIX, but will
rather cause the parameters in the memory resident program to be changed (the
new parameters, including options, will replace those previously loaded).

NOTE:     Although INSFIX can run in high memory through the use of the DOS
          5.0 LOADHIGH command, this practice is not recommended. The
          technique which INSFIX uses to located a previously loaded version
          (and communicate new parameters) is not compatible with high
          memory, and thus a copy of INSFIX loaded in high memory cannot be
          removed without rebooting.  However, INSFIX only occupies 2.4K of
          memory, so this is generally not a problem.


4.   How INSFIX Works
---------------------

To help in understanding the use of INSFIX, some discussion of internal
operation will be provided.

When a DOS file OPEN or FIND FIRST command (functions 3D and 4E) or a
LOAD/EXECUTE command (function 4B, if the /X option is specified) is called
by an application program, INSFIX intercepts the DOS call.  INSFIX will then
attempt the DOS call exactly as specified by the application.  If the return
code indicates successful completion, control is returned to the DOS
application (i.e. INSFIX will have no effect).

If, however, the return from the DOS call indicates the file operation
failed, INSFIX will parse the specified path name to isolate the file name
and file extension.  It will then append the file name on to the INSFIX paths
(PATH1 through PATH10), and attempt the same file operation with each new
path.  This process is repeated until all INSFIX paths have been tried, or a
successful file operation results.  If any of these calls are successful,
control is returned to the DOS application.  If all INSFIX paths fail, the
application will receive the DOS failure code.

INSFIX uses it's search paths in the order specified; that is PATH1 is tried
first, followed by PATH2 etc.

The operation of the INSFIX /R and /S command switches will only affect
redirected file operations - that is file functions which use the INSFIX
paths.  If the path specified by the application was successful, the /R and
/S options will have no effect.

INSFIX paths may be specified with an optional drive letter (e.g.
D:\INSMARK), or without the drive letter, in which case the current drive
will be used for appended directories.


5.   An Example
---------------

The INSMARK application is tailored for each insurance carrier by utilizing a
custom batch file.  A data file from the particular insurance carrier's
software is copied to the Insmark private directory (the data file is called
BUTTON), and then INSMARK is started.  To configure this system, the
following INSFIX command would be utilized at each workstation:

     INSFIX H:\INSMARK /S /X

     Where H:\INSMARK is the location of the shared INSMARK files.

Assuming a filed called "LOCAL" was located in the current directory
(C:\PRIVATE), and a filed called "SHARED" was located in the common INSMARK
directory (H:\INSMARK), the following file open commands would actually
result in different files being opened:

     OPEN PATH REQUEST        ACTUAL FILE OPENED
     -----------------        ------------------
     C:\PRIVATE\LOCAL         C:\PRIVATE\LOCAL
     LOCAL                    C:\PRIVATE\LOCAL
     C:\LOCAL                 <not found>
     C:\PRIVATE\SHARED        H:\INSMARK\SHARED
     SHARED                   H:\INSMARK\SHARED
     C:\SHARED                H:\INSMARK\SHARED

In the above example, an open command for the "SHARED" file would have the
share permissions changed to DENY/NONE (because of the /S switch), preventing
any share violations in a multi-user environment.

Because the /X switch was provided, any programs not found in the current
directory can be loaded from the specified shared directories (without
requiring the DOS PATH statement to be modified).  In addition, the /X option
will attempt to load executable files from the shared directory even if the
DOS command specified a full path.  For example, if the user typed "C:\BMENU"
(to run a program called BMENU.EXE) which was not found in the C:\ directory,
and a copy did exist in the H:\INSMARK directory, that copy would be loaded.
This behaves differently from the DOS PATH command.


6.   Using INSFIX with Single User Applications
----------------------------------------------

INSFIX can be used to make some types of in-house developed single-user
applications operate in a multi-user environment, with limitations.

If the application has a number of files from which it only reads data
(including program files and overlays), and only has a few files that it
writes to, this program can be made to operate multi-user, with a private
copy of the "write" data for each user (the application cannot share output
files unless it is specifically written for a network).

To configure the above application, all common "read only" files and programs
should be located in a shared directory (lets say H:\SHARED).  All files
which are written by the application should be copied to local private
directories (for example, C:\PRIVATE).

On each workstation, the user would install INSFIX, with H:\SHARED specified
as the redirected path.  To prevent share violations, the /R option can be
utilized (in which case all shared files must be made READ/ONLY using the DOS
ATTRIB command), or the /S option should be used.

The following INSFIX command could be used:

     INSFIX H:\SHARED /R /X


Although the DOS Append command can also be used in some cases to perform the
same function, INSFIX is smaller than Append (2.4K verses 10K), can be
removed from memory when finished, and has the optional share arguments to
ensure that sharing violations do not result.


7.   Ordering INSFIX
--------------------

A fully operational copy of INSFIX is obtainable directly from ZyBel for a
cost of $99 per network.  ZyBel accepts VISA, Mastercard, American Express,
or COD company check.

Please address all inquiries to:

     ZyBel MicroSystems Inc.
     ATTN: Warren Belkin
     PO Box 1284
     Weston, CT  06883-0284

     203-226-8800
     203-226-8851 (FAX)

     Compuserve ID: 70571, 3651


8.   ZyBel MicroSystems Inc.
----------------------------

ZyBel MicroSystems Inc. is a software developer and Authorized Artisoft
reseller specializing in LANs, custom Voice Response applications, and Wide
Area Networking products (T1, LAN Bridging etc).

ZyBel maintains offices in Fairfield County, CT and Herndon, VA, and has a
technical support center located in Dallas, TX.


*    All products of other companies mentioned in this file are trademarks of
     their respective manufacturers.