Re: LANANA: To Pending Device Number Registrants

Richard Gooch
2001-05-16T18:27:18Z

Andrzej Krzysztofowicz writes:
> >
> > OK, just correct me if I get this wrong, but this code is taking the LAST 2
> > characters of the device name and verifying that it is "cd". Which would
> > mean that the standard states that "/dev/ginsucd" would be a CD-ROM drive?
> >
> > That is why I feel a "name" of a device handle shouldnt set how a driver
> > operates in this fashion... if you make a small error in your compare, you
> > might try to eject a Ginsu Cabbage Dicer instead of a cdrom drive... OOPS!
> >
> > Sam Bingner
> >
> > Alan Cox writes:
> > > > len = readlink ("/proc/self/3", buffer, buflen);
> > > > if (strcmp (buffer + len - 2, "cd") != 0) {
> > > > fprintf (stderr, "Not a CD-ROM! Bugger off.\n");
> > > > exit (1);
> > >
> > > And on my box cd is the cabbage dicer whoops
> >
> > Actually, no, because it's guaranteed that a trailing "/cd" is a
> > CD-ROM. That's the standard.
>
> Sure, you no longer support /dev/sdcd (eighty-second SCSI disk)...

Then you haven't looked at what devfs actually does. *All* CD-ROMs
will have a trailing pathname component of "/cd". In other words, the
name of the leaf node in it's parent directory is "cd".
The FAQ describes this.

Regards,

Richard....
Permanent: rgooch@atnf.csiro.au
Current: rgooch@ras.ucalgary.ca