tests/tail/tail-c.sh

   1 #!/bin/sh
   2 # exercise tail -c
   3
   4 # Copyright 2014-2024 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 <https://www.gnu.org/licenses/>.
  18
  19 . "${srcdir=.}/tests/init.sh"; path_prepend_ ./src
  20 print_ver_ tail
  21
  22 # Make sure it works on funny files in /proc and /sys.
  23 for file in /proc/version /sys/kernel/profiling; do
  24   if test -r $file; then
  25     cp -f $file copy &&
  26     tail -c -1 copy > exp || framework_failure_
  27
  28     tail -c -1 $file > out || fail=1
  29     compare exp out || fail=1
  30   fi
  31 done
  32
  33 # Make sure it works for pipes
  34 printf '123456' | tail -c3 > out || fail=1
  35 printf '456' > exp || framework_failure_
  36 compare exp out || fail=1
  37
  38 # Any part of /dev/zero should be valid for tail -c.
  39 head -c 4096 /dev/zero >exp || fail=1
  40 tail -c 4096 /dev/zero >out || fail=1
  41 compare exp out || fail=1
  42
  43 # Any part of /dev/urandom, if it exists, should be valid for tail -c.
  44 if test -r /dev/urandom; then
  45   timeout --verbose 1 tail -c 4096 /dev/urandom >/dev/null || fail=1
  46 fi
  47
  48 Exit $fail