tests/tail/end-of-device.sh

   1 #!/bin/sh
   2 # Ensure that tail seeks to the end of a device
   3
   4 # Copyright (C) 2017-2024 Free Software Foundation, Inc.
   5
   6 # This program is free software: you can redistribute it and/or modify
   7 # it under the terms of the GNU General Public License as published by
   8 # the Free Software Foundation, either version 3 of the License, or
   9 # (at your option) any later version.
  10
  11 # This program is distributed in the hope that it will be useful,
  12 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 # GNU General Public License for more details.
  15
  16 # You should have received a copy of the GNU General Public License
  17 # along with this program.  If not, see <https://www.gnu.org/licenses/>.
  18
  19 . "${srcdir=.}/tests/init.sh"; path_prepend_ ./src
  20 print_ver_ tail
  21
  22 # need write access to local device
  23 # (even though we don't actually write anything)
  24 require_root_
  25 require_local_dir_
  26
  27 get_device_size() {
  28   BLOCKDEV=blockdev
  29   $BLOCKDEV -V >/dev/null 2>&1 || BLOCKDEV=/sbin/blockdev
  30   $BLOCKDEV --getsize64 "$1"
  31 }
  32
  33 # Get path to device the current dir is on.
  34 # Note df can only get fs size, not device size.
  35 device=$(df --output=source . | tail -n1) || framework_failure_
  36
  37 dev_size=$(get_device_size "$device") ||
  38   skip_ "failed to determine size of $device"
  39
  40 tail_offset=$(expr $dev_size - 1023) ||
  41   skip_ "failed to determine tail offset"
  42
  43 timeout 10 tail -c 1024 "$device" > end1 || fail=1
  44 timeout 10 tail -c +"$tail_offset" "$device" > end2 || fail=1
  45 test $(wc -c < end1) = 1024 || fail=1
  46 cmp end1 end2 || fail=1
  47
  48 Exit $fail