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 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 2 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, write to the Free Software
  19 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  20 # 02110-1301, USA.
  21
  22
  23 # This bug was fixed for 5.0.91
  24 # It skips the test if your system lacks a /proc/$pid/status
  25 # file, or if its contents don't look right.
  26
  27 if test "$VERBOSE" = yes; then
  28   set -x
  29   tail --version
  30 fi
  31
  32 sleep 2 &
  33 pid=$!
  34 sleep .5
  35 grep '^State:[   ]*[S]' /proc/$pid/status > /dev/null 2>&1 || \
  36   {
  37     echo "$0:/proc/$pid/status: missing or 'different': skipping this test" 1>&2
  38     (exit 77); exit 77
  39   }
  40 kill $pid
  41
  42 pwd=`pwd`
  43 t0=`echo "$0"|sed 's,.*/,,'`.tmp; tmp=$t0/$$
  44 trap 'status=$?; cd "$pwd" && chmod -R u+rwx $t0 && rm -rf $t0 && exit $status' 0
  45 trap '(exit $?); exit $?' 1 2 13 15
  46
  47 framework_failure=0
  48 mkdir -p $tmp || framework_failure=1
  49 cd $tmp || framework_failure=1
  50 touch empty || framework_failure=1
  51 echo anything > nonempty || framework_failure=1
  52
  53 if test $framework_failure = 1; then
  54   echo "$0: failure in testing framework" 1>&2
  55   (exit 1); exit 1
  56 fi
  57
  58 fail=0
  59
  60 for file in empty nonempty; do
  61   for c_or_n in c n; do
  62     tail --sleep=4 -${c_or_n} 0 -f $file &
  63     pid=$!
  64     sleep .5
  65     set _ `sed -n '/^State:[     ]*\([^  ]\)/s//\1/p' /proc/$pid/status`
  66     shift # Remove the leading `_'.
  67     state=$1
  68     case $state in
  69       S*) ;;
  70       *) echo $0: process in unexpected state: $state 1>&2; fail=1 ;;
  71     esac
  72     kill $pid
  73   done
  74 done
  75
  76 (exit $fail); exit $fail