tests/du/long-sloop.sh

   1 #!/bin/sh
   2 # Use du to exercise a corner of fts's FTS_LOGICAL code.
   3 # Show that du fails with ELOOP (Too many levels of symbolic links)
   4 # when it encounters that condition.
   5
   6 # Copyright (C) 2006-2019 Free Software Foundation, Inc.
   7
   8 # This program is free software: you can redistribute it and/or modify
   9 # it under the terms of the GNU General Public License as published by
  10 # the Free Software Foundation, either version 3 of the License, or
  11 # (at your option) any later version.
  12
  13 # This program is distributed in the hope that it will be useful,
  14 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 # GNU General Public License for more details.
  17
  18 # You should have received a copy of the GNU General Public License
  19 # along with this program.  If not, see <https://www.gnu.org/licenses/>.
  20
  21 . "${srcdir=.}/tests/init.sh"; path_prepend_ ./src
  22 print_ver_ du
  23
  24 # Create lots of directories, each containing a single symlink
  25 # pointing at the next directory in the list.
  26
  27 # This number should be larger than the number of symlinks allowed in
  28 # file name resolution, but not too large as a number of entries
  29 # in a single directory.
  30 n=400
  31
  32 dir_list=$(seq $n)
  33 mkdir $dir_list || framework_failure_
  34 file=1
  35 i_minus_1=0
  36 for i in $dir_list $(expr $n + 1); do
  37   case $i_minus_1 in
  38   0) ;;
  39   *)
  40     ln -s ../$i $i_minus_1/s || framework_failure_
  41     file=$file/s;;
  42   esac
  43   i_minus_1=$i
  44 done
  45 echo foo > $i || framework_failure_
  46
  47 # If a system can handle this many symlinks in a file name,
  48 # just skip this test.
  49
  50 # The following also serves to record in 'err' the string
  51 # corresponding to strerror (ELOOP).  This is necessary because while
  52 # Linux/libc gives 'Too many levels of symbolic links', Solaris
  53 # renders it as "Number of symbolic links encountered during path
  54 # name traversal exceeds MAXSYMLINKS".
  55
  56 cat $file > /dev/null 2> err &&
  57     skip_ 'Your system appears to be able to handle more than $n symlinks
  58 in file name resolution'
  59 too_many=$(sed 's/.*: //' err)
  60
  61
  62 # With coreutils-5.93 there was no failure.
  63 # With coreutils-5.94 we get the desired diagnostic:
  64 # du: cannot access '1/s/s/s/.../s': Too many levels of symbolic links
  65 du -L 1 > /dev/null 2> out1 && fail=1
  66 sed "s, .1/s/s/s/[/s]*',," out1 > out || framework_failure_
  67
  68 echo "du: cannot access: $too_many" > exp || framework_failure_
  69
  70 compare exp out || fail=1
  71
  72 Exit $fail