[TriLUG] How reliable is inotifywait?

[Aaron Morrison via TriLUG]

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>
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>>> that
>>>>> address.
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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.
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>>> Welcome to TriLUG: https://trilug.org/welcome
>> 
>> 
> --
> This message was sent to: Aaron Morrison <ae4ko1 at gmail.com>
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