From: Tom Cloyd <tomcloyd@...>
Date: 2008-03-04T19:58:55+09:00
Subject: problems closing a CD

I'm utterly baffled by this simple problem in a ruby program I've run a 
number of time on Windows. I'm now running Kubuntu Linux, and things 
work differently (!).

This program reads a series of data CDs, cataloging their contents. To 
stop the process, I input a zero length volume label (well, on Windows I 
do, anyway; on Linux this errors off, but that's not my current problem).

What I can't do is get the CD just read in to be released by the program 
so I can read in the next one.

Code:

 > archive_source_dir = '/cdrom'  # this is where the CD appears when I 
put it in the drive

Processing begins when the program has the volume label of the CD (this 
is used as the key in a hash containing an array of the tree paths). 
When it has traversed the directory tree on the CD, it asks for the next 
volume label. In Windows, I just punch the open button on the drive, 
replaced the CD with a new one, close the drive, keyed in the new volume 
label, and kept going. Linux won't release the CD.

I've tried many things to get the CD to go release, including...
 > archive_source_dir.close
 > IO.close(archive_source_dir)
 > File.close(archive_source_dir)

I get "undefined method" errors on everything. I have no idea why. Isn't 
everything a file in linux? Guess not.

Plainly I'm missing some simple concept here, but I can't see it.

Would appreciate any help.

Tom