Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!linus!philabs!cmcl2!seismo!ut-sally!ut-ngp!ut-dillo!darin
From: darin@ut-dillo.UUCP (Darin Adler)
Newsgroups: net.micro.mac
Subject: Re: How to find LaserWriter file (actually GetVRefNum)
Message-ID: <165@ut-dillo.UUCP>
Date: Fri, 11-Apr-86 01:20:35 EST
Article-I.D.: ut-dillo.165
Posted: Fri Apr 11 01:20:35 1986
Date-Received: Sun, 13-Apr-86 07:22:08 EST
References: <42@uva.UUCP>
Organization: UTexas Computation Center, Austin, Texas
Lines: 31
Summary: Use BootDisk

In article <42@uva.UUCP>, dolf@uva.UUCP (Dolf Starreveld) writes:
> My idea was:
> 	1) Look at STR resource ID -8192 in the System file to find out
> 	   what the currently selected printer is.
> 	2) Use the name contained in the resource as the name of the file
> 	   with the printer driver. (Is this the correct way of determing
> 	   the name of the LW file?)
> Problem:
> 	Generally my application won't be in the System Folder, nor will it
> 	be on the same disk as the System Folder. Therefore calling OpenResFile
> 	won't always result in actually opening the LaserWriter file. To 
> 	accomplish this I need to no the vRefNum of the volume the LW file
> 	is located on.

(Dolf then mentions Aztec C)

The System Folder is always open as a Working Directory under HFS.  That
means that there is always a WDRefNum (or vRefNum) that identifies it, under
MFS *or* HFS.  That vRefNum is stored in a low-memory global, "BootDrive".
Contrary to what that misleading name may have you believe, this contains
the WDRefNum (or vRefNum) of the System Folder.  I do not program much in C,
but I think that something like this should do the trick:

#define BootDrive (* (short *) 0x210)

Good Luck,
-- 
Darin Adler	...!ut-sally!ut-dillo!darin	darin@dillo.CC.UTEXAS.EDU

"...'cause they don't go for what's in the book and that makes 'em bad..."
								Frank Zappa