Re: config(5) break down

[Masao Uebayashi <uebayasi%gmail.com@localhost>]

On Mon, Mar 22, 2010 at 6:14 AM, Sverre Froyen <sverre%viewmark.com@localhost> 
wrote:
> 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.

That's part of the plan of "my devfs".

Masao