Path: utzoo!mnetor!uunet!lll-winken!lll-lcc!lll-tis!ames!mailrus!tut.cis.ohio-state.edu!ut-sally!utah-cs!utah-gr!uplherc!sp7040!obie!wsccs!dave
From: dave@wsccs.UUCP (VAX Headroom @ The End of the Galaxy)
Newsgroups: comp.os.vms
Subject: Re: VMS logicals help -> dir and -> sub-dir
Message-ID: <163@wsccs.UUCP>
Date: 17 Feb 88 23:28:13 GMT
References: <722@zycad.UUCP>
Lines: 44
Keywords: vms4.5, logicals
Summary: How to append a NULL directory

In article <722@zycad.UUCP>, kjb@zycad.UUCP (Kevin Buchs) writes:
> 
> If I define a logical as node::disk:[directory] then there is no way to
> refer to subdirectories.  If I instead define the logical as
> node::disk:[directory.] (notice the trailing dot) then this logical does
> allow [sub-directory] to be appended.  It however cannot be used without
> appending a subdirectory, and there is no way to append a null subdirectory.

$ define x node::disk:[directory.] /translate=conceiled

$ dir x:[000000] will give you the top directory.
I like to refer to logical names defined the way x above is as "fake
devices"
since they will appear to be a device in directory listings and they
act like devices.  000000 is how you get THE root directory on a disk
like dir $disk1:[000000].  We used to have $disk1 defined as
sys$sysdevice:[disk1.]/trans=conc when we had one disk drive and put
our users there.  When we got a new disk drive we redefined $disk1 to be
dub0:/trans=conc and did a copy sys$sysdevice:[*...] $disk1:[...]
and it worked fine.  No changes to the authorize records were necessary.

Anyway, 000000 is equivalent to the "root" directory on a "device", or,
if you prefer, a null directory.

you may occasionally see outputs from these types of things as
dua0:[disk1.][000000] or dua0:[disk1.][user1.c]
Also, this only works once, you can't have
define x dua0:[disk1.]/trans=conc
define y x:[xyz.]/trans=conc
as the result of dir y:[a] would be
(internally)
dir dua0:[disk1.][xyz.][a]
and VMS wont buy this.  (at least the last time I tried it.)

Also, using "fake devices" it is possible to get directories more
than eight levels deep.

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|		    |	     Dave E Martin       | DISCLAIMER: Been Cancelled |
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