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Re: What is "discover -t" saying?



On 2018-06-24 at 09:27, Richard Owlett wrote:

> On 06/24/2018 08:16 AM, The Wanderer wrote:
>
>> On 2018-06-24 at 08:10, Richard Owlett wrote:
>> 
>>> The discover(1) manpage does not describe output format/fields.
>>> The relevant output line is:> Prolific Technology, Inc. PL25A1 Host-Host
>>> Bridge unknown unknown
>>>
>>> There are two fields whose content is "unknown".
>>> What are they?
>>> TIA
>> 
>> If you look at the "Examples" section of the man page, you'll see that
>> the first example given includes four lines which consist *only* of
>> "unknown unknown".
>> 
>>  From that, and from the information provided on the other lines from the
>> output examples, I infer that the output format is "vendor model".
>> (Those terms are listed under the third example, "Get model and vendor
>> information by type".)
>> 
>> In other words: this line represents a device of an unknown model, from
>> an unknown vendor.
>> 
>> (All of that is my inference and interpretation, not based on anything
>> more solid. Even assuming I've got it right, I agree that the man page
>> could be clearer about this.)
> 
> Except [ <grin> &/or <groan> ], lsusb reports:
>> Bus 004 Device 062: ID 067b:25a1 Prolific Technology, Inc. PL25A1 Host-Host Bridge
> The "067b" is Vendor ID.
> The "25a1" identifies a particular device of that manufacturer.

Yes; that's for the Prolific Technology device.

As indicated by the fact that the man-page examples put "unknown
unknown" on a separate line, I think that "unknown unknown" represents a
completely separate device; I don't think it's related to the Prolific
Technology device at all. I think the fact that they appeared on one
line in your mail is an artifact of a line-wrapping mistake somewhere in
the process.

-- 
   The Wanderer

The reasonable man adapts himself to the world; the unreasonable one
persists in trying to adapt the world to himself. Therefore all
progress depends on the unreasonable man.         -- George Bernard Shaw

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