#!/bin/sh
# Ensure that tail -f works on an append-only file
# Requires root access to do chattr +a, as well as an ext[23] or xfs file system

# Copyright (C) 2006 Free Software Foundation, Inc.

# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.

# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.

# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
# 02110-1301, USA.

if test "$VERBOSE" = yes; then
  set -x
  tail --version
fi

PRIV_CHECK_ARG=require-root . $srcdir/../priv-check

pwd=`pwd`
t0=`echo "$0"|sed 's,.*/,,'`.tmp; tmp=$t0/$$
trap 'status=$?; cd "$pwd" && chmod -R u+rwx $t0 && rm -rf $t0 && exit $status' 0
trap '(exit $?); exit $?' 1 2 13 15

framework_failure=0
mkdir -p $tmp || framework_failure=1
cd $tmp || framework_failure=1

touch f
chattr +a f 2>/dev/null || framework_failure=1
( echo x > f ) 2>/dev/null && framework_failure=1
echo x >> f || framework_failure=1

if test $framework_failure = 1; then
  echo "$0: chattr +a doesn't work on this file system; skipping this test " 1>&2
  (exit 77); exit 77
fi

fail=0

sleep 1 &
pid=$!
tail --pid=$pid -f f > /dev/null 2>&1 || fail=1
chattr -a f 2>/dev/null

(exit $fail); exit $fail