tests/tail/wait.sh

   1 #!/bin/sh
   2 # Make sure that 'tail -f' returns immediately if a file doesn't exist
   3 # while 'tail -F' waits for it to appear.
   4
   5 # Copyright (C) 2003-2024 Free Software Foundation, Inc.
   6
   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 3 of the License, or
  10 # (at your option) any later version.
  11
  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.
  16
  17 # You should have received a copy of the GNU General Public License
  18 # along with this program.  If not, see <https://www.gnu.org/licenses/>.
  19
  20 . "${srcdir=.}/tests/init.sh"; path_prepend_ ./src
  21 print_ver_ tail
  22
  23 grep '^#define HAVE_INOTIFY 1' "$CONFIG_HEADER" >/dev/null \
  24   && HAVE_INOTIFY=1
  25
  26 inotify_failed_re='inotify (resources exhausted|cannot be used)'
  27
  28 touch here || framework_failure_
  29 { touch unreadable && chmod a-r unreadable; } || framework_failure_
  30
  31 # Terminate any background tail process
  32 cleanup_() { kill $pid 2>/dev/null && wait $pid; }
  33
  34 # speedup non inotify case
  35 fastpoll='-s.1 --max-unchanged-stats=1'
  36
  37 for mode in '' '---disable-inotify'; do
  38   returns_ 124 timeout 10 tail $fastpoll -f $mode not_here && fail=1
  39
  40   if test ! -r unreadable; then # can't test this when root
  41     returns_ 124 timeout 10 tail $fastpoll -f $mode unreadable && fail=1
  42   fi
  43
  44   returns_ 124 timeout .1 tail $fastpoll -f $mode here 2>tail.err || fail=1
  45
  46   # 'tail -F' must wait in any case.
  47
  48   returns_ 124 timeout .1 tail $fastpoll -F $mode here 2>>tail.err || fail=1
  49
  50   if test ! -r unreadable; then # can't test this when root
  51     returns_ 124 timeout .1 tail $fastpoll -F $mode unreadable || fail=1
  52   fi
  53
  54   returns_ 124 timeout .1 tail $fastpoll -F $mode not_here || fail=1
  55
  56   grep -Ev "$inotify_failed_re" tail.err > x
  57   mv x tail.err
  58   compare /dev/null tail.err || fail=1
  59   >tail.err
  60 done
  61
  62 if test "$HAVE_INOTIFY" && test -z "$mode" && is_local_dir_ .; then
  63   # Ensure -F never follows a descriptor after rename
  64   # either with tiny or significant delays between operations
  65   tail_F()
  66   {
  67     local delay="$1"
  68
  69     > k && > tail.out && > tail.err || framework_failure_
  70     tail $fastpoll -F $mode k >tail.out 2>tail.err & pid=$!
  71     sleep $delay
  72     mv k l
  73     sleep $delay
  74     touch k
  75     mv k l
  76     sleep $delay
  77     echo NO >> l
  78     sleep $delay
  79     cleanup_
  80     rm -f k l
  81
  82     test -s tail.out \
  83       && ! grep -E "$inotify_failed_re" tail.err >/dev/null
  84   }
  85
  86   retry_delay_ tail_F 0 1 && { cat tail.out; fail=1; }
  87   retry_delay_ tail_F .2 1 && { cat tail.out; fail=1; }
  88 fi
  89
  90 Exit $fail