tests/mv/symlink-onto-hardlink-to-self.sh

   1 #!/bin/sh
   2 # Demonstrate that when moving a symlink onto a hardlink-to-that-symlink,
   3 # an error is presented.  Depending on your kernel (e.g., Linux, Solaris,
   4 # but not NetBSD), prior to coreutils-8.16, the mv would successfully perform
   5 # a no-op.  I.e., surprisingly, mv s1 s2 would succeed, yet fail to remove s1.
   6
   7 # Copyright (C) 2012-2019 Free Software Foundation, Inc.
   8
   9 # This program is free software: you can redistribute it and/or modify
  10 # it under the terms of the GNU General Public License as published by
  11 # the Free Software Foundation, either version 3 of the License, or
  12 # (at your option) any later version.
  13
  14 # This program is distributed in the hope that it will be useful,
  15 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 # GNU General Public License for more details.
  18
  19 # You should have received a copy of the GNU General Public License
  20 # along with this program.  If not, see <https://www.gnu.org/licenses/>.
  21
  22 . "${srcdir=.}/tests/init.sh"; path_prepend_ ./src
  23 print_ver_ mv
  24
  25 # Create a file f, and a symlink s1 to that file.
  26 touch f || framework_failure_
  27 ln -s f s2 || framework_failure_
  28
  29 # Attempt to create a hard link to that symlink.
  30 # On some systems, it's not possible: they create a hard link to the referent.
  31 ln s2 s1 || framework_failure_
  32
  33 # If s1 is not a symlink, skip this test.
  34 test -h s1 \
  35   || skip_ your kernel or file system cannot create a hard link to a symlink
  36
  37 for opt in '' --backup; do
  38
  39   if test "$opt" = --backup; then
  40     mv $opt s1 s2 > out 2>&1 || fail=1
  41     compare /dev/null out || fail=1
  42
  43     # Ensure that s1 is gone.
  44     test -e s1 && fail=1
  45
  46     # With --backup, ensure that the backup file was created.
  47     ref=$(readlink s2~) || fail=1
  48     test "$ref" = f || fail=1
  49   else
  50     echo "mv: 's1' and 's2' are the same file" > exp
  51     mv $opt s1 s2 2>err && fail=1
  52     compare exp err || fail=1
  53
  54     # Ensure that s1 is still present.
  55     test -e s1 || fail=1
  56
  57     # Without --backup, ensure there is no backup file.
  58     test -e s2~ && fail=1
  59   fi
  60
  61 done
  62
  63 Exit $fail