2 # Demonstrate a bug in `tail -cN' when operating on files of size 4G and larger
3 # Fixed in coreutils-4.5.2.
5 # Copyright (C) 2002, 2003, 2006 Free Software Foundation, Inc.
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 2 of the License, or
10 # (at your option) any later version.
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.
17 # You should have received a copy of the GNU General Public License
18 # along with this program; if not, write to the Free Software
19 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
22 . $srcdir/../expensive
24 if test "$VERBOSE" = yes; then
30 t0=`echo "$0"|sed 's,.*/,,'`.tmp; tmp=$t0/$$
31 trap 'status=$?; cd "$pwd" && chmod -R u+rwx $t0 && rm -rf $t0 && exit $status' 0
32 trap '(exit $?); exit $?' 1 2 13 15
35 mkdir -p $tmp || framework_failure=1
36 cd $tmp || framework_failure=1
38 # Create a file of size exactly 4GB (2^32) with 8 bytes
39 # at the beginning and another set of 8 bytes at the end.
40 # The rest will be NUL bytes. On most modern systems, the following
41 # creates a file that takes up only a few KB. Here, du -sh says 16K.
42 echo abcdefgh | tr -d '\n' > big || framework_failure=1
43 echo 87654321 | tr -d '\n' > tmp || framework_failure=1
45 dd bs=1 seek=4294967288 if=tmp of=big 2> err || dd_failed=1
46 if test "$dd_failed" = 1; then
48 echo "$0: cannot create a file large enough for this test," 1>&2
49 echo "$0: possibly because this system doesn't support large files;" 1>&2
50 echo "$0: Consider rerunning this test on a different file system." 1>&2
54 if test $framework_failure = 1; then
55 echo "$0: failure in testing framework" 1>&2
61 tail -c1 big > out || fail=1
69 test $fail = 1 && diff out exp 2> /dev/null
71 (exit $fail); exit $fail