Re: config(5) break down

[Sverre Froyen <sverre%viewmark.com@localhost>]

On Sat March 20 2010 17:24:07 David Young wrote:
> On Sat, Mar 20, 2010 at 09:43:21AM -0700, Matt Thomas wrote:
> > On Mar 20, 2010, at 9:06 AM, Masao Uebayashi wrote:
> > > On Sun, Mar 21, 2010 at 1:01 AM, Matt Thomas 
> > > <matt%3am-software.com@localhost> 
wrote:
> > >> I'm talking about <maj, min> to device.  How, as a user, do I know
> > >> what actual tty does /dev/ttyXX open?
> > >
> > > If we make tty(4) a device, we can lookup its parent by drvctl(8)
> > > (extend it to return dv_parent).
> >
> > That is user unfriendly.  The name in /dev should tell me enough to
> > know what it is.  I should not have to invoke another command to
> > figure that out.
> 
> When you say "what it is," it's not clear whether you mean "what kind"
> or "what instance".  I have a machine with eleven "dial-out" /dev/
> nodes:
> 
> crw-rw----  1 uucp  dialer  8, 524288 Mar 20 13:35 /dev/dty00
> crw-rw----  1 uucp  dialer  8, 524289 Mar 20 13:35 /dev/dty01
> crw-rw----  1 uucp  dialer  8, 524290 Nov  9  2003 /dev/dty02
> crw-rw----  1 uucp  dialer  8, 524291 Mar 10 18:48 /dev/dty03
> crw-rw----  1 uucp  dialer  8, 524292 Mar 10 18:48 /dev/dty04
> crw-rw----  1 uucp  dialer  8, 524293 Mar 10 18:48 /dev/dty05
> crw-rw----  1 uucp  dialer  8, 524294 Mar 18 19:57 /dev/dty06
> crw-rw----  1 uucp  dialer  8, 524295 Mar 10 18:47 /dev/dty07
> crw-rw----  1 uucp  dialer  8, 524296 Mar 20 13:34 /dev/dty08
> crw-rw----  1 uucp  dialer  8, 524297 Mar 10 18:46 /dev/dty09
> crw-rw----  1 uucp  dialer  8, 524298 Mar 19 23:58 /dev/dty10
> 
> It's handy that I can type 'man dty' to see what kind they are, but
> beyond that, the listing is not user-friendly: apart from the stand-out
> modification time, nothing distinguishes /dev/dty02, the only node that
> has no hardware backing, from the rest.  Nothing distinguishes dty00 -
> dty01, which are built into the motherboard, from dty03 - dty10, which
> reside on a puc(4).  Luckily, dty03 - dty10 correspond directly to
> tentacles 1 - 8 of the puc(8).

Could this be resolved by adding a "get label" ioctl that could be used on any 
device?  It might return a descriptive string from the device driver / config 
file.

Regards,
Sverre