1#!/bin/sh 2# demonstrate that tail -F works for currently missing dirs 3# Before coreutils-8.6, tail -F missing/file would not 4# notice any subsequent availability of the missing/file. 5 6# Copyright (C) 2010-2023 Free Software Foundation, Inc. 7 8# This program is free software: you can redistribute it and/or modify 9# it under the terms of the GNU General Public License as published by 10# the Free Software Foundation, either version 3 of the License, or 11# (at your option) any later version. 12 13# This program is distributed in the hope that it will be useful, 14# but WITHOUT ANY WARRANTY; without even the implied warranty of 15# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16# GNU General Public License for more details. 17 18# You should have received a copy of the GNU General Public License 19# along with this program. If not, see <https://www.gnu.org/licenses/>. 20 21. "${srcdir=.}/tests/init.sh"; path_prepend_ ./src 22print_ver_ tail 23 24check_tail_output() 25{ 26 local delay="$1" 27 grep "$tail_re" out > /dev/null || 28 { sleep $delay; return 1; } 29} 30 31# Terminate any background tail process 32cleanup_() { kill $pid 2>/dev/null && wait $pid; } 33 34# Speedup the non inotify case 35fastpoll='-s.1 --max-unchanged-stats=1' 36 37for mode in '' '---disable-inotify'; do 38 rm -rf out missing 39 40 tail $mode -F $fastpoll missing/file > out 2>&1 & pid=$! 41 42 # Wait up to 12.7s for tail to start with diagnostic: 43 # tail: cannot open 'missing/file' for reading: No such file or directory 44 tail_re='cannot open' retry_delay_ check_tail_output .1 7 || 45 { cat out; fail=1; } 46 47 mkdir missing || framework_failure_ 48 (cd missing && echo x > file) || framework_failure_ 49 50 # Wait up to 12.7s for this to appear in the output: 51 # "tail: '...' has appeared; following new file" 52 tail_re='has appeared' retry_delay_ check_tail_output .1 7 || 53 { echo "$0: file: unexpected delay?"; cat out; fail=1; } 54 55 cleanup_ 56done 57 58 59Exit $fail 60