Re: inotify and /proc/<pid>

[Joseph Pingenot <trelane@digitasaru.net>]

>From Al Viro on Tuesday, 31 July, 2007:
>On Mon, Jul 30, 2007 at 10:31:13PM -0500, Joseph Pingenot wrote:
>> >From Joseph Pingenot on Monday, 30 July, 2007:
>> >From Al Viro on Tuesday, 31 July, 2007:
>> >>On Mon, Jul 30, 2007 at 09:16:16PM -0500, Joseph Pingenot wrote:
>> >>> I was trying to use inotify to watch process changes (especially process
>> >>>   termination) by watching /proc/<pid>.
>> >>> Sadly, although I could see something reading various files, nothing
>> >>>   was issued when the process I was watching exited and the directory
>> >>>   went away.
>> >>> Is this intentional, or a bug?
>> >>It's a bug you intend to introduce in your program...  IOW, don't
>> >>do that.
>> >More background, please?
>> >What's the way to check for a process exiting without spinning?
>> I should also specify that the process being waited on is not a
>>   child process-it's just some other process on the system.
>Umm...  Any details on intended use?  IOW, is that "I want to write
>an utility that would wait for given PID to exit, just for the hell
>of it" or is there something you are trying to implement using that?

I'm trying to implement pwait.  It blocks until a specified PID exits,
  and then it exits.

You can use it to do other stuff after a program finishes.

While we're on the subject, is there some way to receive notification
  that some aspect of a process changes (in this case, stopping using
  CPU, but not exiting).

Thanks for the time to help me figure this out.

-Joseph

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