tests/tail/F-vs-rename.sh

   1 #!/bin/sh
   2 # Demonstrate that tail -F works when renaming the tailed files.
   3 # Between coreutils 7.5 and 8.2 inclusive, 'tail -F a b' would
   4 # stop tracking additions to b after 'mv a b'.
   5
   6 # Copyright (C) 2009-2024 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_ tail
  23
  24 check_tail_output() {
  25   local delay="$1"
  26   if [ "$tail_re" ]; then
  27     grep "$tail_re" err ||
  28       { sleep $delay; return 1; }
  29   else
  30     local tail_re="==> $file <==@$data@"
  31     tr '\n' @ < out | grep "$tail_re" > /dev/null ||
  32       { sleep $delay; return 1; }
  33   fi
  34   unset tail_re
  35 }
  36
  37 # Terminate any background tail process
  38 cleanup_() { kill $pid 2>/dev/null && wait $pid; }
  39
  40 # Speedup the non inotify case
  41 fastpoll='-s.1 --max-unchanged-stats=1'
  42
  43 for mode in '' '---disable-inotify'; do
  44   rm -f a b out err
  45   touch a b || framework_failure_
  46
  47   tail $mode -F $fastpoll a b >out 2>err & pid=$!
  48
  49   # Wait up to 12.7s for tail to start.
  50   echo x > a
  51   file=a data=x retry_delay_ check_tail_output .1 7 || { cat out; fail=1; }
  52
  53   mv a b || framework_failure_
  54
  55   # Wait 12.7s for this diagnostic:
  56   # tail: 'a' has become inaccessible: No such file or directory
  57   tail_re='inaccessible' retry_delay_ check_tail_output .1 7 ||
  58     { cat out; fail=1; }
  59
  60   # Wait 12.7s for this diagnostic:
  61   # tail: 'b' has been replaced;  following new file
  62   tail_re='replaced' retry_delay_ check_tail_output .1 7 ||
  63     { cat out; fail=1; }
  64   # Wait up to 12.7s for "x" to be displayed:
  65   file='b' data='x' retry_delay_ check_tail_output .1 7 ||
  66     { echo "$0: b: unexpected delay?"; cat out; fail=1; }
  67
  68   echo x2 > a
  69   # Wait up to 12.7s for this to appear in the output:
  70   # "tail: '...' has appeared;  following new file"
  71   tail_re='has appeared' retry_delay_ check_tail_output .1 7 ||
  72     { echo "$0: a: unexpected delay?"; cat out; fail=1; }
  73   # Wait up to 12.7s for "x2" to be displayed:
  74   file='a' data='x2' retry_delay_ check_tail_output .1 7 ||
  75     { echo "$0: a: unexpected delay 2?"; cat out; fail=1; }
  76
  77   echo y >> b
  78   # Wait up to 12.7s for "y" to appear in the output:
  79   file='b' data='y' retry_delay_ check_tail_output .1 7 ||
  80     { echo "$0: b: unexpected delay 2?"; cat out; fail=1; }
  81
  82   echo z >> a
  83   # Wait up to 12.7s for "z" to appear in the output:
  84   file='a' data='z' retry_delay_ check_tail_output .1 7 ||
  85     { echo "$0: a: unexpected delay 3?"; cat out; fail=1; }
  86
  87   cleanup_
  88 done
  89
  90 Exit $fail