From owner-freebsd-bugs Thu Feb 8 11:30:21 2001 Delivered-To: freebsd-bugs@hub.freebsd.org Received: from freefall.freebsd.org (freefall.freebsd.org [216.136.204.21]) by hub.freebsd.org (Postfix) with ESMTP id C9C5837B69D for ; Thu, 8 Feb 2001 11:30:01 -0800 (PST) Received: (from gnats@localhost) by freefall.freebsd.org (8.11.1/8.11.1) id f18JU1c07040; Thu, 8 Feb 2001 11:30:01 -0800 (PST) (envelope-from gnats) Received: from freefall.freebsd.org (freefall.freebsd.org [216.136.204.21]) by hub.freebsd.org (Postfix) with ESMTP id 058CA37B65D for ; Thu, 8 Feb 2001 11:26:06 -0800 (PST) Received: (from nobody@localhost) by freefall.freebsd.org (8.11.1/8.11.1) id f18JQ5706603; Thu, 8 Feb 2001 11:26:05 -0800 (PST) (envelope-from nobody) Message-Id: <200102081926.f18JQ5706603@freefall.freebsd.org> Date: Thu, 8 Feb 2001 11:26:05 -0800 (PST) From: kmarx@vicor-nb.com To: freebsd-gnats-submit@FreeBSD.org X-Send-Pr-Version: www-1.0 Subject: bin/24955: /usr/bin/tail -F in 4.1+ doesn't work if file inode changes (works in 4.0) Sender: owner-freebsd-bugs@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org >Number: 24955 >Category: bin >Synopsis: /usr/bin/tail -F in 4.1+ doesn't work if file inode changes (works in 4.0) >Confidential: no >Severity: non-critical >Priority: low >Responsible: freebsd-bugs >State: open >Quarter: >Keywords: >Date-Required: >Class: sw-bug >Submitter-Id: current-users >Arrival-Date: Thu Feb 08 11:30:01 PST 2001 >Closed-Date: >Last-Modified: >Originator: ken marx >Release: 4.2-RELEASE FreeBSD 4.2-RELEASE >Organization: vicor >Environment: FreeBSD sploot.vicor-nb.com 4.2-RELEASE FreeBSD 4.2-RELEASE #0: Fri Jan 5 16:27:52 PST 2001 kmarx@sploot.vicor-nb.com:/usr/src/sys/compile/KMARX i386 >Description: There appears to be a difference in /usr/bin/tail -F between 4.0 and 4.1+. It's not updating the inode it's doing the tail -F on when the inode changes. (E.g., if you tail through a soft link and the link moves.) This doesn't match the man page: -F The -F option implies the -f option, but tail will also check to see if the file being followed has been renamed or rotated. The file is closed and reopened when tail detects that the filename being read from has a new inode number. The -F option is ignored if reading from standard input rather than a file. I just rebuilt a version from a 4.0 soure tree I have, and that works. The difference is in /usr/src/usr.bin/tail/forward.c. The one that doesn't work is: $FreeBSD: src/usr.bin/tail/forward.c,v 1.11.6.1 20 00/07/18 21:49:41 jlemon Exp $. The working 4.0 one has no cvs info. I don't know if this is as it should be. A quick slog throught the freebsd archies shows only a discussion of -f in CURRENT, and a reference to a version of /usr/src/sys/kern/kern_event.c,v 1.14 that doesn't easily compare to our 4.2 kern_event.c,v 1.2.2.4. Doesn't seem relevant... I'll use my 4.0 version of tail, but thought someone might know or care what the real deal is. >How-To-Repeat: 1. create file /tmp/poot1 containing: 1 poot1 2 poot1 3 poot1 4 poot1 5 poot1 6 poot1 7 poot1 8 poot1 2. creat file /tmp/poot2 containing: 1 poot2 2 poot2 3 poot2 4 poot2 5 poot2 6 poot2 7 poot2 8 poot2 3. Create a link to /tmp/poot1: ln -s /tmp/poot1 /tmp/pootlnk 4. In a separate shell, tail the link: tail -F /tmp/pootlnk 5. remove the link: rm /tmp/pootlnk 6. recreate the link pointing to the other file ln -s /tmp/poot2 /tmp/pootlnk In 4.0 the tail -F will correctly show: 1 poot1 2 poot1 3 poot1 4 poot1 5 poot1 6 poot1 7 poot1 8 poot1 1 poot2 2 poot2 3 poot2 4 poot2 5 poot2 6 poot2 7 poot2 8 poot2 (And will continue to update correctly for any rm/ln sequence when the new target of the link is != to the previous target) In 4.1+ it will only show: 1 poot1 2 poot1 3 poot1 4 poot1 5 poot1 6 poot1 7 poot1 8 poot1 >Fix: >Release-Note: >Audit-Trail: >Unformatted: To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-bugs" in the body of the message