From: Jano Svitok Date: 2008-03-04T22:07:20+09:00 Subject: Re: problems closing a CD On Tue, Mar 4, 2008 at 1:15 PM, Tom Cloyd wrote: > > Jano Svitok wrote: > > On Tue, Mar 4, 2008 at 11:58 AM, Tom Cloyd wrote: > > > >> 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 > >> > > > > I guess this has something to do with mounting/umounting, though I > > don't know too much about automatic mounting in kubuntu. > > Try using `umount /cdrom` after you are done. (Don't forget to close > > any open files and move away from that dir). > > You might encounter some privileges problems ("only root can do") - > > try sudo in that case, or modify /etc/fstab to allow users to > > mount/umount. > > > > `eject` and `eject -t` might be useful as well. > > > > > > > The problem is that I need an unmount WHILE the program is running, and > it won't let go of the device. When I tried to close it, ruby refuses to > acknowledge knowing anything about "close". It appears that there is no > kernal#close, suddenly. Nothing works. I open the device and cannot shut > it down. If I try to do this through Linux, while my program is running, > I get "umount: /media/cdrom0: device is busy". It's a ruby problem - or > rather my problem in using ruby. > > So, again...having done this > >archive_source_dir = '/cdrom' > how do I "undo" it? > > > Any more ideas? 1. lsof will show you your process' open files. 2. Make sure to use block form of File.open instead of File.new - it will close the file when you're done with it. 3. Instead of archive_source_dir.close() do Dir.chdir('/') or somewhere else. Or even better, use block form of Dir.chdir if you need to chdir into /cdrom 4. if you could post minimal program that makes trouble, maybe some more ideas will pop up. (e.g. strip as much as you can while it still causes the problem - I guess just traversing the CD will be enough)