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From: ephraim@wang.UUCP (pri=8 Ephraim Vishniac x76659 ms1459)
Newsgroups: net.micro.mac
Subject: Checking for volume busy?
Message-ID: <784@wang.UUCP>
Date: Mon, 31-Mar-86 08:34:06 EST
Article-I.D.: wang.784
Posted: Mon Mar 31 08:34:06 1986
Date-Received: Sat, 5-Apr-86 03:17:14 EST
Distribution: net
Organization: Wang Labs, Lowell MA
Lines: 17

While trying to write a passably safe disk formatting program, I
wanted to check whether the target volume was busy (had open files).
In both the hardcover IM and the 12/85 supplement, the File Manager
chapter says that bit 6 of vcbAtrb will be set if the volume is busy.
In fact, it's set whether the volume is busy or not.  It's even set
in the on-disk copy of the attribute bytes.  I was tempted to use
_GetFCBInfo (tersely described in the 12/85 supplement), but it's
listed in the MDS equates as an HFS-only call.  So, I wound up 
traversing the FCB list myself.  This doesn't give me warm feelings,
even though I check fsFCBLen and vary the FCB size for MFS versus HFS.
I'm not convinced, for example, that it would warn me about files open
inside HFS subdirectories (folders).

Does anyone know a more reliable way to determine whether a volume is busy?

Thanks, Ephraim
decvax!wanginst!wang!ephraim