tests/tail-2/descriptor-vs-rename.sh

   1 #!/bin/sh
   2 # Demonstrate that tail -f works when renaming the tailed files.
   3 # Between coreutils 7.5 and 8.23 inclusive, 'tail -f a' would
   4 # stop tracking additions to b after 'mv a b'.
   5
   6 # Copyright (C) 2015-2016 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 <http://www.gnu.org/licenses/>.
  20
  21 . "${srcdir=.}/tests/init.sh"; path_prepend_ ./src
  22 print_ver_ tail
  23
  24 check_tail_output()
  25 {
  26   local delay="$1"
  27   grep "$tail_re" out ||
  28     { sleep $delay; return 1; }
  29 }
  30
  31 # Terminate any background tail process
  32 cleanup_() { kill $pid 2>/dev/null && wait $pid; }
  33
  34 # Speedup the non inotify case
  35 fastpoll='-s.1 --max-unchanged-stats=1'
  36
  37 for mode in '' '---disable-inotify'; do
  38   rm -f a out
  39   touch a || framework_failure_
  40
  41   tail $mode $fastpoll -f a > out 2>&1 & pid=$!
  42
  43   # Wait up to 12.7s for tail to start.
  44   echo x > a
  45   tail_re='^x$' retry_delay_ check_tail_output .1 7 || { cat out; fail=1; }
  46
  47   mv a b || framework_failure_
  48
  49   echo y >> b
  50   # Wait up to 12.7s for "y" to appear in the output:
  51   tail_re='^y$' retry_delay_ check_tail_output .1 7 || { cat out; fail=1; }
  52
  53   cleanup_
  54 done
  55
  56 Exit $fail