tests/tail-2/infloop-1

   1 #!/bin/sh
   2 # This test would fail with tail from pre-1.22i textutils.
   3
   4 # Copyright (C) 1999, 2002, 2006-2011 Free Software Foundation, Inc.
   5
   6 # This program is free software: you can redistribute it and/or modify
   7 # it under the terms of the GNU General Public License as published by
   8 # the Free Software Foundation, either version 3 of the License, or
   9 # (at your option) any later version.
  10
  11 # This program is distributed in the hope that it will be useful,
  12 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 # GNU General Public License for more details.
  15
  16 # You should have received a copy of the GNU General Public License
  17 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18
  19 . "${srcdir=.}/init.sh"; path_prepend_ ../src
  20 print_ver_ tail
  21
  22 yes > t &
  23 yes_pid=$!
  24 while :; do
  25   test -s t && break
  26   sleep .1
  27 done
  28 tail -n 1 t &
  29 tail_pid=$!
  30 kill $yes_pid
  31
  32 # This test is racy, and can fail under unusual circumstances.
  33 # On a very busy system, tail will fail to notice that $yes_pid is gone.
  34 # Then the following kill will succeed and cause this test to fail.
  35
  36 # Wait for up to 3 seconds for tail to detect the death of $yes_pid.
  37 for i in $(seq 30); do
  38     kill -0 $tail_pid || break
  39     echo sleep 0.1s
  40     sleep .1
  41 done
  42
  43 kill $tail_pid && fail=1 || :
  44
  45 Exit $fail