tests/tail-2/big-4gb

   1 #!/bin/sh
   2 # Demonstrate a bug in `tail -cN' when operating on files of size 4G and larger
   3 # Fixed in coreutils-4.5.2.
   4
   5 # Copyright (C) 2002, 2003, 2006-2007 Free Software Foundation, Inc.
   6
   7 # This program is free software: you can redistribute it and/or modify
   8 # it under the terms of the GNU General Public License as published by
   9 # the Free Software Foundation, either version 3 of the License, or
  10 # (at your option) any later version.
  11
  12 # This program is distributed in the hope that it will be useful,
  13 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 # GNU General Public License for more details.
  16
  17 # You should have received a copy of the GNU General Public License
  18 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19
  20 if test "$VERBOSE" = yes; then
  21   set -x
  22   tail --version
  23 fi
  24
  25 . $srcdir/../expensive
  26 . $srcdir/../test-lib.sh
  27
  28 # Create a file of size exactly 4GB (2^32) with 8 bytes
  29 # at the beginning and another set of 8 bytes at the end.
  30 # The rest will be NUL bytes.  On most modern systems, the following
  31 # creates a file that takes up only a few KB.  Here, du -sh says 16K.
  32 echo abcdefgh | tr -d '\n' > big || framework_failure
  33 echo 87654321 | tr -d '\n' > tmp || framework_failure
  34 # Seek 4GB - 8
  35 dd bs=1 seek=4294967288 if=tmp of=big 2> err || dd_failed=1
  36 if test "$dd_failed" = 1; then
  37   cat err 1>&2
  38   echo "$0: cannot create a file large enough for this test," 1>&2
  39   echo "$0: possibly because this system doesn't support large files;" 1>&2
  40   echo "$0: Consider rerunning this test on a different file system." 1>&2
  41   (exit 77); exit 77
  42 fi
  43
  44 fail=0
  45
  46 tail -c1 big > out || fail=1
  47 # Append a newline.
  48 echo >> out
  49 cat <<\EOF > exp
  50 1
  51 EOF
  52
  53 compare out exp || fail=1
  54
  55 (exit $fail); exit $fail