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 # This bug was fixed for 5.0.91
   5 # It skips the test if your system lacks a /proc/$pid/status
   6 # file, or if its contents don't look right.
   7
   8 if test "$VERBOSE" = yes; then
   9   set -x
  10   tail --version
  11 fi
  12
  13 sleep 2 &
  14 pid=$!
  15 sleep .5
  16 grep '^State:[   ]*[S]' /proc/$pid/status > /dev/null 2>&1 || \
  17   {
  18     echo "$0:/proc/$pid/status: missing or 'different': skipping this test" 1>&2
  19     (exit 77); exit 77
  20   }
  21 kill $pid
  22
  23 pwd=`pwd`
  24 t0=`echo "$0"|sed 's,.*/,,'`.tmp; tmp=$t0/$$
  25 trap 'status=$?; cd $pwd; chmod -R u+rwx $t0; rm -rf $t0 && exit $status' 0
  26 trap '(exit $?); exit $?' 1 2 13 15
  27
  28 framework_failure=0
  29 mkdir -p $tmp || framework_failure=1
  30 cd $tmp || framework_failure=1
  31 touch empty || framework_failure=1
  32 echo anything > nonempty || framework_failure=1
  33
  34 if test $framework_failure = 1; then
  35   echo "$0: failure in testing framework" 1>&2
  36   (exit 1); exit 1
  37 fi
  38
  39 fail=0
  40
  41 for file in empty nonempty; do
  42   for c_or_n in c n; do
  43     tail --sleep=4 -${c_or_n} 0 -f $file &
  44     pid=$!
  45     sleep .5
  46     set _ `sed -n '/^State:[     ]*\([^  ]\)/s//\1/p' /proc/$pid/status`
  47     shift # Remove the leading `_'.
  48     state=$1
  49     case $state in
  50       S*) ;;
  51       *) echo $0: process in unexpected state: $state 1>&2; fail=1 ;;
  52     esac
  53     kill $pid
  54   done
  55 done
  56
  57 (exit $fail); exit $fail