Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!deimos.cis.ksu.edu!uxc!tank!eecae!cps3xx!rang
From: rang@cpsin3.cps.msu.edu (Anton Rang)
Newsgroups: comp.sys.mac.programmer
Subject: Re: Mac file IO
Message-ID: <3264@cps3xx.UUCP>
Date: 3 Jun 89 05:29:24 GMT
References: <16464@paris.ics.uci.edu>
Sender: usenet@cps3xx.UUCP
Reply-To: rang@cpswh.cps.msu.edu (Anton Rang)
Organization: Michigan State University, Computer Science Dept.
Lines: 29
In-reply-to: poleary@BONNIE.ICS.UCI.EDU's message of 2 Jun 89 20:02:31 GMT

In article <16464@paris.ics.uci.edu> poleary@BONNIE.ICS.UCI.EDU (Peter O'Leary) writes:

   An application that I am working on needs to save information on a file so
   that that file may be opened later.  What is the minimum amount of info []
   that is needed in order to get at a file?  So far, I have been storing the
   file's name and volume reference number.

It depends on how much later you need the file, to some extent, but
what I'd recommend storing is:

	Volume name (refnum is only valid for one session)
	Directory ID (for an HFS volume)
	File name

For an MFS volume, you can assume that the file version is 0 without
problems unless some other weird software is changing the version.
Also, in theory, all you should need is:

	Volume name
	Directory ID
	File number

but I don't know of any file system call to open a file by number, so
I think you need to use the filename.

+---------------------------+------------------------+
| Anton Rang (grad student) | "VMS Forever!"         |
| Michigan State University | rang@cpswh.cps.msu.edu |
+---------------------------+------------------------+