coreutils/tests/misc/truncate-owned-by-other.sh

#!/bin/sh
# Demonstrate that "truncate -s0 writable-but-owned-by-other" works.

# Copyright (C) 2008-2013 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 3 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, see <http://www.gnu.org/licenses/>.

. "${srcdir=.}/tests/init.sh"; path_prepend_ ./src
print_ver_ truncate

require_root_

group_num=$(id -g $NON_ROOT_USERNAME)

# Create a file owned by root, and writable by $NON_ROOT_USERNAME.
echo > root-owned || framework_failure_
chgrp +$group_num . root-owned || framework_failure_
chmod g+w root-owned

# Ensure that the current directory is searchable by $NON_ROOT_USERNAME.
chmod g+x .

setuidgid $NON_ROOT_USERNAME env PATH="$PATH" truncate -s0 root-owned || fail=1

Exit $fail