[TriLUG] How reliable is inotifywait?

[Scott Lambdin via TriLUG]

Ah

On Mon, Mar 11, 2024, 5:05 PM Aaron Morrison <ae4ko1 at gmail.com> wrote:

> If I know Steve, he won’t bother or need to see that article. ;-)   But
> yes, systemd can do what he wants — he just doesn’t use systemd.
>
> (Hi Steve!)
>
> --am
>
>
> > On Mar 11, 2024, at 18:39, Scott Lambdin via TriLUG <trilug at trilug.org>
> wrote:
> >
> > Interesting.  I saw a web page called "Replacing incron with systemd."
> > Looks like there may be a new way to do it.  I can't get to the page,
> > perhaps because I am at a cigar bar in Mexico.
> >
> >> On Mon, Mar 11, 2024, 4:06 PM Scott Lambdin <lopaki at gmail.com> wrote:
> >>
> >> iNotify/incron has been around like ten years.  If you can find an
> active
> >> incron message board, that would probably be a good place to look for
> >> failure reports.
> >>
> >> On Sun, Mar 10, 2024, 5:24 PM James Toebes via TriLUG <
> trilug at trilug.org>
> >> wrote:
> >>
> >>> Have you checked out incron?   Similar to cron,  but runs on inodes.
> >>> You can easily define script that run when a file is added, deleted....
> >>>
> >>>
> >>> On 3/10/24 18:41, Ken VanDine via TriLUG wrote:
> >>>> In my experience it's very reliable.  We use it in Ubuntu to determine
> >>> when
> >>>> the display server is up before starting the installer.
> >>>>
> >>>>
> >>>
> https://github.com/canonical/ubuntu-core-desktop-installer/blob/00cb18b0b2512bb81986c6259d5561fc5a9e3976/launcher/launcher#L57
> >>>>
> >>>> Cheers,
> >>>> Ken
> >>>>
> >>>>
> >>>> On Sun, Mar 10, 2024, 6:09 PM Steve Litt via TriLUG <
> trilug at trilug.org>
> >>>> wrote:
> >>>>
> >>>>> Hi all,
> >>>>>
> >>>>> The inotifywait program waits until a specific file event happens in
> a
> >>>>> specific directory or file, and then terminates. So it enables
> >>>>> file-driven event driven programs.
> >>>>>
> >>>>> I'd like to wake up the instant a file appears in a directory.
> >>>>> Something like the following:
> >>>>>
> >>>>> inotifywait -e create -e moved_to -t 30 /tmp/pager
> >>>>>
> >>>>> The preceding waits 30 seconds, except if a file is created in or
> moved
> >>>>> to /tmp/pager, it quits waiting and terminates immediately.
> >>>>>
> >>>>> I use it to combine polling with an event driven, so if for some
> reason
> >>>>> the event (moved_to or create) doesn't quit and terminate
> immediately,
> >>>>> it will still quit and terminate at the end of 30 seconds.
> >>>>>
> >>>>> I can significantly simplify my program if I changed -t 30 to t -1,
> >>>>> where -1 stands for "forever". False positives aren't a problem: They
> >>>>> would just start another cycle. But false negatives, where a file is
> >>>>> created or moved into /tmp/pager but fails to quit and terminate,
> would
> >>>>> really mess me up in this particular situation.
> >>>>>
> >>>>> So what do you think, is inotifywait reliable?
> >>>>>
> >>>>> Thanks,
> >>>>>
> >>>>> SteveT
> >>>>>
> >>>>> Steve Litt
> >>>>>
> >>>>> Autumn 2023 featured book: Rapid Learning for the 21st Century
> >>>>> http://www.troubleshooters.com/rl21
> >>>>> --
> >>>>> This message was sent to: Ken VanDine <ken at vandine.org>
> >>>>> To unsubscribe, send a blank message to trilug-leave at trilug.org from
> >>> that
> >>>>> address.
> >>>>> TriLUG mailing list : https://www.trilug.org/mailman/listinfo/trilug
> >>>>> Unsubscribe or edit options on the web  :
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> >>>>> Welcome to TriLUG: https://trilug.org/welcome
> >>> --
> >>> This message was sent to: Scott Lambdin <lopaki at gmail.com>
> >>> To unsubscribe, send a blank message to trilug-leave at trilug.org from
> >>> that address.
> >>> TriLUG mailing list : https://www.trilug.org/mailman/listinfo/trilug
> >>> Unsubscribe or edit options on the web  :
> >>> https://www.trilug.org/mailman/options/trilug/lopaki%40gmail.com
> >>> Welcome to TriLUG: https://trilug.org/welcome
> >>
> >>
> > --
> > This message was sent to: Aaron Morrison <ae4ko1 at gmail.com>
> > To unsubscribe, send a blank message to trilug-leave at trilug.org from
> that address.
> > TriLUG mailing list : https://www.trilug.org/mailman/listinfo/trilug
> > Unsubscribe or edit options on the web    :
> https://www.trilug.org/mailman/options/trilug/ae4ko1%40gmail.com
> > Welcome to TriLUG: https://trilug.org/welcome
>