tests/tail-2/tail-n0f

   1 #!/bin/sh
   2 # Make sure that `tail -n0 -f' and `tail -c0 -f' sleep
   3 # rather than doing what amounted to a busy-wait.
   4
   5 # Copyright (C) 2003, 2006-2012 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 <http://www.gnu.org/licenses/>.
  19
  20 # This bug was fixed for 5.0.91
  21 # It skips the test if your system lacks a /proc/$pid/status
  22 # file, or if its contents don't look right.
  23
  24 . "${srcdir=.}/init.sh"; path_prepend_ ../src
  25 print_ver_ tail
  26
  27 require_proc_pid_status_
  28
  29 touch empty || framework_failure_
  30 echo anything > nonempty || framework_failure_
  31
  32
  33 for inotify in ---disable-inotify ''; do
  34   for file in empty nonempty; do
  35     for c_or_n in c n; do
  36       tail --sleep=4 -${c_or_n} 0 -f $inotify $file &
  37       pid=$!
  38       tail_sleeping()
  39       {
  40         local delay="$1"; sleep $delay
  41         state=$(get_process_status_ $pid)
  42         case $state in
  43           S*) ;;
  44           *) return 1;;
  45         esac
  46       }
  47       # Wait up to 1.5s for tail to sleep
  48       retry_delay_ tail_sleeping .1 4 ||
  49         { echo $0: process in unexpected state: $state >&2; fail=1; }
  50       kill $pid
  51     done
  52   done
  53 done
  54
  55 Exit $fail