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From: dhesi@bsu-cs.UUCP
Newsgroups: comp.os.eunice
Subject: Re: Eunice can't deal with 5-part newsgroup names
Message-ID: <609@bsu-cs.UUCP>
Date: Fri, 15-May-87 16:13:41 EDT
Article-I.D.: bsu-cs.609
Posted: Fri May 15 16:13:41 1987
Date-Received: Sun, 17-May-87 00:58:30 EDT
References: <511@nbs-amrf.UUCP> <14750001@acf4.UUCP>
Reply-To: dhesi@bsu-cs.UUCP (Rahul Dhesi)
Organization: CS Dept, Ball St U, Muncie, Indiana
Lines: 39
Summary: Conceptual integrity better explains VMS's flakiness

In article <14750001@acf4.UUCP> tihor@acf4.UUCP (Stephen Tihor) valiantly
tries to explain the 8-level subdirectory limit in VAX/VMS thus:
>The 8 level limit was explained as being an arbitrary number to prevent 
>problems on endless looping if the directory structure was changed from a
>simple tree into a complex graph with a loop in it....

Not a plausible explanation.  The VMS directory structure is not
permitted to be a graph with a loop in it.   Even if it did support a
generalized graph structure one day, that still would be no
justification for such a small limit.  For example, 4.3BSD does support
a complex graph structure via symbolic links, but will translate up to
20 symbolic links before giving diagnosing an infinite loop.

>                                                  ...It also permited he
>computation of an upper limit on fully qualified file name size.  This is
>useful since most VMS tools actually check buffer limits for too long
>file names rather than just trashing their internal memory and doing
>arbitrary damage like most unix tools. 

Since directory names can be about 39 characters long, and filenames
can be about 80 characters long, the calculated upper limit on a
complete pathname would be about 500 characters, allowing some space
for a network node name or device name or logical name.  I doubt that
most VMS utilities use 500-character fixed-size arrays to avoid
checking filename length.

What is more likely that limits such as this one are necessary
to maintain conceptual integrity in an operating system that spends
much of its time comparing various parameters against their
defined limits.  (Try "show process/quota" to see a long list.)
Examples of other meaningless limits are:  command procedures may have
only up to 8 parameters;  passwords may not contain most special
characters.

WHAT?  YOU CAN'T HAVE A PASSWORD WITH A * OR / IN IT?  WHY??

Conceptual integrity.  Don't leave home without it.
-- 
Rahul Dhesi         UUCP:  {ihnp4,seismo}!{iuvax,pur-ee}!bsu-cs!dhesi