Path: utzoo!utgpu!water!watmath!clyde!rutgers!husc6!ut-sally!ut-emx!mic
From: mic@ut-emx.UUCP (Mic Kaczmarczik)
Newsgroups: comp.os.vms
Subject: Re: Unix 'ish file link on vms
Summary: Be *very* careful when you use SET FILE/ENTER
Keywords: Unix links VMS file headers
Message-ID: <732@ut-emx.UUCP>
Date: 4 Feb 88 06:21:22 GMT
References: <68rrk@byuvax.bitnet>
Reply-To: mic@emx.utexas.edu (Mic Kaczmarczik)
Organization: UT Austin Computation Center, User Services
Lines: 29
Posted: Thu Feb  4 00:21:22 1988

In article <68rrk@byuvax.bitnet> rrk@byuvax.bitnet writes:
>Look at help on the command:
>$ set file/enter=nn2 nn1

And read it *very* carefully.  Creating a file entry in this manner
makes a new name for the file, but does *not* make the new name a
complete substitute for the old one.

As I understand it, this is because unlike Unix, where the file header
does not contain any information about a file's name, VMS file headers
do.  There is also a reference to the file's parent directory.  Thus
there is a ``primary'' name for a file, and any other name entries (as
created by SET FILE/ENTER) are ``secondary''.

This doesn't mean that extra file entries shouldn't be used, but they
should be used with care.  Depending on your application, they may or
may not be useful for simulating Unix-style hard file links, so be
sure to read the documentation before you create any.

Mic Kaczmarczik

P.S. My apologies in advance for any misstatements or inaccuracies;
it's been a while since I've dealt with file entries.

-- 
Mic Kaczmarczik			don't push me 'cause I'm standing in line.
UT Austin Computation Center	here -- calm down -- have a sip of wine.
mic@emx.cc.utexas.edu		it's like a party sometimes it makes me wonder
CCEP001@UTADNX.BITNET		how I keep myself so slender