1 files changed, 48 insertions, 0 deletions
diff --git a/tests/tail-2/end-of-device.sh b/tests/tail-2/end-of-device.sh
new file mode 100755
index 0000000..3f624db
--- /dev/null
+++ b/tests/tail-2/end-of-device.sh
@@ -0,0 +1,48 @@
+#!/bin/sh
+# Ensure that tail seeks to the end of a device
+
+# Copyright (C) 2017-2020 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 <https://www.gnu.org/licenses/>.
+
+. "${srcdir=.}/tests/init.sh"; path_prepend_ ./src
+print_ver_ tail
+
+# need write access to local device
+# (even though we don't actually write anything)
+require_root_
+require_local_dir_
+
+get_device_size() {
+  BLOCKDEV=blockdev
+  $BLOCKDEV -V >/dev/null 2>&1 || BLOCKDEV=/sbin/blockdev
+  $BLOCKDEV --getsize64 "$1"
+}
+
+# Get path to device the current dir is on.
+# Note df can only get fs size, not device size.
+device=$(df --output=source . | tail -n1) || framework_failure_
+
+dev_size=$(get_device_size "$device") ||
+  skip_ "failed to determine size of $device"
+
+tail_offset=$(expr $dev_size - 1023) ||
+  skip_ "failed to determine tail offset"
+
+timeout 10 tail -c 1024 "$device" > end1 || fail=1
+timeout 10 tail -c +"$tail_offset" "$device" > end2 || fail=1
+test $(wc -c < end1) = 1024 || fail=1
+cmp end1 end2 || fail=1
+
+Exit $fail