tests/misc/head-pos.sh

   1 #!/bin/sh
   2 # When reading a specified number of lines, ensure that the output
   3 # file pointer is positioned just after those lines.
   4
   5 # Copyright (C) 2002-2017 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 . "${srcdir=.}/tests/init.sh"; path_prepend_ ./src
  21 print_ver_ head
  22
  23 (echo a; echo b) > in || framework_failure_
  24 echo b > exp || framework_failure_
  25
  26 for i in -1 1; do
  27   (head -n $i >/dev/null; cat) < in > out || fail=1
  28   compare exp out || fail=1
  29 done
  30
  31 # Exercise the (start_pos < pos) block in elide_tail_lines_seekable.
  32 # So far, this is the only test to do that.
  33 # Do that by creating a file larger than BUFSIZ (I've seen 128K) and
  34 # elide a suffix of it (by line count) that is also larger than BUFSIZ.
  35 # 50000 lines times 6 bytes per line gives us enough leeway even on a
  36 # system with a BUFSIZ of 256K.
  37 n_lines=50000
  38 seq 70000 > in2 || framework_failure_
  39 echo $n_lines > exp-n || framework_failure_
  40
  41 (head -n-$n_lines>/dev/null; wc -l) < in2 > n
  42 compare exp-n n || fail=1
  43
  44 Exit $fail