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From: cahill@dit.ie
Newsgroups: comp.dcom.lans
Subject: Re: What does "link" mean in a 3Com LAN?
Message-ID: <7158.25c887bc@dit.ie>
Date: 1 Feb 90 19:02:20 GMT
References: <213.25c4249b@acci.com>
Organization: Dublin Institute of Technology
Lines: 102

In article <213.25c4249b@acci.com>, ta2@acci.com writes:
> I got tossed a Tech Support question about my client's product as
> it runs on 3Com (3Plus I believe.) We have absolutely no information
> about 3Com...
> 
> I have been told that the application program does not "unlink" at
> program exit. What does this mean?
> 
> In other words - what do the terms "link" and "unlink" mean in the
> context of a 3Com network?
> 
In article <213.25c4249b@acci.com>, ta2@acci.com writes:

> I have been told that the application program does not "unlink" at
> program exit. What does this mean?
> 
> In other words - what do the terms "link" and "unlink" mean in the
> context of a 3Com network?
> 

	3+File LINK (3F LINK) maps part of the server file area to
	a virtual drive e.g.

	  A>3f link f: \\sys\msword

	will assign virtual drive f: to a server file area where MSWORD
	lives. 

	where:

		3f is the 3Plus program
		link is a 3f command
		f: is the virtual drive
		\\sys\msword is a 3+ SHARENAME that maps to a directory
		  on the server.
		  (format is: \\user\name in this case sys is the SERVER
		  user (a special user). Users can set up their own
		  SHARE names and these will be referenced by prefixing 
		  the user name to make them unique.

	To run an application the following cycle is usually performed:

	  3f link f: \\user\application
	  f:application
	  3f unlink f:

	where f: is a virtual drive.

	I think your problem is that a drive is being linked for the
	application and not being unlinked, later somebody expects
	this drive to be linked to some where else.

	To avoid this type of problem adopt a few simple conventions
	to achieve consistency.

	3Com recommend the following:

	o Avoid link "real drives" e.g. floppy A, B or hard disc C:

	o Link as follows:

	  Net drive	SHARENAME	Purpose

	  D:		\\sys\apps	the top directory under which all
					applications software lives in 
					separate subdirectories.

	  E:		home directory	Users private file space on the server.

	A few conventions I decided on area as follows:

	o When running an application always link drive f: to where it
	  resides. We use 3+Menus as the user interface and there is a
	  facility for doing this.

	o Use APPEND and PATH to f: so that the application can always
	  find its own program or data files if needed. Again in 3+Menus
	  we invoke a batch file F.BAT and pass it the application name
	  as the first parameter. F.BAT is:

	    APPEND f:		! APPEND before PATH or PATH will dissappear
	    PATH f:
	    %1 %2 %3 %4 %5	! run application with parameters (max=4)

	Most applications (not all) will gladly work this way and you
	don't need a special startup batch file for each one, f.BAT
	will do for most. The net drive f: is being reassigned (LINKED)
	differently for each application.

	If you are not using 3+Menus you could simply adapt f.bat
	I see only one problem:

	  3+Menus ensures that the PATH and APPEND assignments made by
	  f.bat are only temporary and your original settings are preserved.
	  How it does this I don't know but would be interested to find out.
	  Normally if you run a batch job with such commands your original
	  settings will be overwritten.


Conor Cahill
Dublin Institute of Technology
cahill@dit.ie