Re: Review of a simple autovt script for alpine

From: Didier Kryn <didier.kryn_at_free.fr>
Date: Fri, 23 May 2025 16:52:03 +0200

Le 23/05/2025 à 13:10, Laurent Bercot a écrit :
> Second thing: last time I checked, you could not use inotify on
> sysfs to watch for file creation. Has it changed? If it has, it's
> awesome, but it would only work on recent kernels, so unfortunately
> that's not usable on a generic distribution (unless they stick to very
> recent kernels).

     Hi. I'm just lurking on Skarnet, but I could comment on this remark
about inotify.

     It's actually too bad that inotify doesn't work on sysfs and
procfs. But there is an alternative method for an application to wake on
asynchronous modification of a file, though I don't think it is
available in a script.

     If you watch /proc/self/mountinfo with select() for exceptional
conditions (exceptfds, in the man page), you get an event whenever the
file is modified. One might imagine that a directory could be watched
the same way for file creation/deletion. I don't know, though, if this
property of /proc/self/mountinfo can be generalized and if it works for
directories and for sysfs, but it is something which might be explored
if the problem is critical.

--     Didier


Received on Fri May 23 2025 - 16:52:03 CEST

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