Bill Brelsford wrote: > Package: coreutils > Version: 7.5-3 > Severity: normal > > "tail -f" no longer works with stdin. E.g. commands such as > > somecommand | tail -f - > somecommand | tail -f > tail -f </var/log/kern > > fail with the message: > > tail: cannot watch `-': No such file or directory > > Worked under 7.4-2 and previous versions.
Thanks for the report. I'm fixing it like this, upstream. Test coming momentarily. >From 30269c9ca38c06b31a7c764c192562e3b0268725 Mon Sep 17 00:00:00 2001 From: Jim Meyering <meyer...@redhat.com> Date: Mon, 7 Sep 2009 08:37:08 +0200 Subject: [PATCH] tail -f: work on "-" once again * src/tail.c (main) [HAVE_INOTIFY]: When stdin (i.e., "-", but not /dev/stdin) is specified on the command line, don't use inotify. Reported by Bill Brelsford in <http://bugs.debian.org/545422>. * NEWS (Bug fixes): Mention it. This bug was introduced in coreutils-7.5 via commit ae494d4b, 2009-06-02, "tail: use inotify if it is available". --- NEWS | 9 +++++++++ src/tail.c | 14 +++++++++++++- 2 files changed, 22 insertions(+), 1 deletions(-) diff --git a/NEWS b/NEWS index b02d2da..5c7fb82 100644 --- a/NEWS +++ b/NEWS @@ -31,6 +31,15 @@ GNU coreutils NEWS -*- outline -*- 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] ** New features diff --git a/src/tail.c b/src/tail.c index e3b9529..c53df9e 100644 --- a/src/tail.c +++ b/src/tail.c @@ -1982,7 +1982,19 @@ main (int argc, char **argv) if (forever) { #if HAVE_INOTIFY - if (!disable_inotify) + /* If the user specifies stdin via a command line argument of "-", + or implicitly by providing no arguments, we won't use inotify. + Technically, on systems with a working /dev/stdin, we *could*, + but would it be worth it? Verifying that it's a real device + and hooked up to stdin is not trivial, while reverting to + non-inotify-based tail_forever is easy and portable. */ + bool stdin_cmdline_arg = false; + + for (i = 0; i < n_files; i++) + if (STREQ (file[i], "-")) + stdin_cmdline_arg = true; + + if (!disable_inotify && !stdin_cmdline_arg) { int wd = inotify_init (); if (wd < 0) -- 1.6.4.2.419.gab238 -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org
