Re: tail broken (?!) and devices not activating

[Celejar <celejar@gmail.com>]

On Tue, 22 Sep 2009 07:59:46 +0200
Sven Joachim <svenjoac@gmx.de> wrote:

> On 2009-09-22 04:17 +0200, Celejar wrote:
> 
> > I'm seeing some really weird problems on my system.  I don't know if
> > they're at all related, but I'll report them both in the same
> > email, in case they are.
> >
> > 1) tail -f stops working - I see the tail of the file, but it fails
> > to refresh when content is added to the file.  What on earth could
> > be causing this?  This is tail from coreutils - nothing fancy, no
> > inotify dependency, just simple polling of the file!
> 
> In coreutils 7.5 tail has gone fancy and uses inotify if possible, see
> the NEWS file.  It works for me, but there are some bugs that have
> been fixed in 7.6 (which is not packaged for Debian yet) that may
> affect you. Citing the coreutils 7.6 NEWS file:
> 
>   tail -f (inotify-enabled) now flushes any initial output before
> blocking. Before, this would print nothing and wait: stdbuf -o 4K
> tail -f /etc/passwd Note that this bug affects tail -f only when its
> standard output is buffered, which is relatively unusual.
>   [bug introduced in coreutils-7.5]
> 
>   tail -f once again works with standard input.  inotify-enabled tail
> -f would fail when operating on a nameless stdin.  I.e., tail -f
> < /etc/passwd would say "tail: cannot watch `-': No such file or
> directory", yet the relatively baroque tail -f /dev/stdin
> < /etc/passwd would work.  Now, the offending usage causes tail to
> revert to its conventional sleep-based (i.e., not inotify-based)
> implementation. [bug introduced in coreutils-7.5]

Thanks, good to know.  Right now, after a reboot into a different
kernel, 'tail -f' is working fine, but I'll bear this in mind if / when
the problem occurs again.

Celejar
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