Testing for a blank DVD
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I've written a small shell script for doing backup that uses mkisofs and cdrecord. I haven't been able to construct the script as a pipe because cdrecord, it seems, needs to know the length of the track it's writing (for a DVD, at least). So if there's no DVD in the drive, mkisofs will spend some time creating an image and then cdrecord will bomb out. I'm looking for a command-line method of testing if a drive has a blank DVD in it. I can check if the drive is mounted using a combination of "mount" and "grep", but you can mount a drive even if there's no media in it, and that method doesn't distinguish between a blank DVD in the drive (good) and no DVD in the drive (bad). As far as I can tell, cdrecord itself has no way of testing for the presence of a blank DVD without actually attempting to write it. So does anyone know a command that I can put into a shell-script test to see if the drive does or does not have a blank DVD? Paul
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On Fri, 2005-03-11 at 18:09, Paul W. Abrahams wrote:
I've written a small shell script for doing backup that uses mkisofs and cdrecord. I haven't been able to construct the script as a pipe because cdrecord, it seems, needs to know the length of the track it's writing (for a DVD, at least). So if there's no DVD in the drive, mkisofs will spend some time creating an image and then cdrecord will bomb out.
I'm looking for a command-line method of testing if a drive has a blank DVD in it. I can check if the drive is mounted using a combination of "mount" and "grep", but you can mount a drive even if there's no media in it, and that method doesn't distinguish between a blank DVD in the drive (good) and no DVD in the drive (bad). As far as I can tell, cdrecord itself has no way of testing for the presence of a blank DVD without actually attempting to write it.
So does anyone know a command that I can put into a shell-script test to see if the drive does or does not have a blank DVD?
Paul
A quick check of cdrecord --help shows a couple of options -atip is one for retrieving info from the disk. As I recall there is a way to retrieve the disk and manufacturer info from a blank. You could use that to test whether a disk is in the drive. -- Ken Schneider UNIX since 1989, linux since 1994, SuSE since 1998 * Only reply to the list please* "The day Microsoft makes something that doesn't suck is probably the day they start making vacuum cleaners." -Ernst Jan Plugge
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On Saturday 12 March 2005 00:31, Ken Schneider wrote:
On Fri, 2005-03-11 at 18:09, Paul W. Abrahams wrote:
I've written a small shell script for doing backup that uses mkisofs and cdrecord. I haven't been able to construct the script as a pipe because cdrecord, it seems, needs to know the length of the track it's writing (for a DVD, at least). So if there's no DVD in the drive, mkisofs will spend some time creating an image and then cdrecord will bomb out.
I'm looking for a command-line method of testing if a drive has a blank DVD in it. I can check if the drive is mounted using a combination of "mount" and "grep", but you can mount a drive even if there's no media in it, and that method doesn't distinguish between a blank DVD in the drive (good) and no DVD in the drive (bad). As far as I can tell, cdrecord itself has no way of testing for the presence of a blank DVD without actually attempting to write it.
So does anyone know a command that I can put into a shell-script test to see if the drive does or does not have a blank DVD?
Paul
A quick check of cdrecord --help shows a couple of options -atip is one for retrieving info from the disk. As I recall there is a way to retrieve the disk and manufacturer info from a blank. You could use that to test whether a disk is in the drive.
There is also "cdinfo" which is in the cdrecord package, which is bound to have some grepable information. Or /usr/sbin/hwinfo --cdrom, which also seems to output information about the inserted media I don't have a recorder available here to say exactly what the output looks like with a blank inserted, but the output from a regular data/movie dvd looks very grepable
participants (3)
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Anders Johansson
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Ken Schneider
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Paul W. Abrahams