Le 29/06/2017 à 17:16, Adam Borowski a écrit :
> On Thu, Jun 29, 2017 at 03:15:33PM +0200, Didier Kryn wrote:
>> Le 29/06/2017 à 14:51, karl@??? a écrit :
>>> Hmm, something similar could be used to create thoose /dev/disk/by-*,
>>> for a static /dev:
>>>
>>> find /dev -type b | xargs blkid | sort | some_script_to_populate_by_xxx
>>>
>>> But if that is only a transformed /sys/class/block, wouldn't it be
>>> easier if there was a /sys/class/uuid or similar ?
>> Everybody is using blkid to build thiese links, my script as well as Udev
>> and Vdev. You probably noticed that blkid has a special option for Udev
>> because Udev people are too lazzy to parse the response. In Vdev, Jude made
>> the parsing job to be compatible with Busybox's blkid which hasn't this
>> special format.
>>
>> So blkid authors on one hand provide a special format for Udev to create
>> the symlinks, and on the other hand claim that they aren't reliable!
>>> Also man blkid says:
> # It is recommended to use lsblk(8) command to get information about
> # block devices rather than blkid. lsblk(8) provides more information,
> # better control on output formatting and it does not require root per‐
> # missions to get actual information.
>
> So as you're making a new tool to parse this information, it's better to
> use the newest and greatest source, thus avoiding that deprecated format.
> Using the library rather than a cmdline program is also an option.
>
blkid does not require root permission. It will actually examine
the block device if you are root; otherwise it will read its cache.
AFAIU, this means you rely on some service ( the hotplugger) to invoke
it as root and refresh the cache when something happens. I hope lsblk is
more than a wrapper for blkid :-)
Didier
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Re: [DNG] I have a question about l…
