Re: [PATCH] doc: describe how kernel inotify support affects tail -f

[Pádraig Brady]

On 23/05/11 18:31, Jim Meyering wrote:
> While "inotify" is specific to the linux kernel, it is
> widespread enough that it's worth mentioning some of the effect
> it has on tail -f:
> 
>>From acbfebeb8d22a87b76fae32d8d9bf0473e178fdf Mon Sep 17 00:00:00 2001
> From: Jim Meyering <address@hidden>
> Date: Mon, 23 May 2011 16:09:42 +0200
> Subject: [PATCH 1/2] doc: describe how kernel inotify support affects tail -f
> 
> * doc/coreutils.texi (tail invocation) [-f]: Mention how inotify
> kernel support makes a difference.
> Prompted by http://bugzilla.redhat.com/662900
> ---
>  doc/coreutils.texi |    5 +++++
>  1 files changed, 5 insertions(+), 0 deletions(-)
> 
> diff --git a/doc/coreutils.texi b/doc/coreutils.texi
> index 289c0ba..dfaf4c9 100644
> --- a/doc/coreutils.texi
> +++ b/doc/coreutils.texi
> @@ -2830,6 +2830,11 @@ tail invocation
>  Likewise, the @option{-f} option has no effect for any
>  operand specified as @samp{-}, when standard input is a FIFO or a pipe.
> 
> +With kernel inotify support, output is asynchronous and generally very 
> prompt.

That's a little ambiguous to me.
Inotify is async wrt time but sync wrt data change.
How about:

"With kernel inotify support, output is triggered by file changes
and generally very prompt."

> +Otherwise, @command{tail} sleeps for one second between checks---
> +use @option{--sleep-interval=@var{N}} to change that default---which can
> +make the output appear slightly less responsive or bursty.

One can also specify sub second intervals:
I've had this alias for years: alias tail='tail -s.1'

cheers,
Pádraig