1#!/bin/sh 2# Make sure that 'tail -f' returns immediately if a file doesn't exist 3# while 'tail -F' waits for it to appear. 4 5# Copyright (C) 2003-2023 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 <https://www.gnu.org/licenses/>. 19 20. "${srcdir=.}/tests/init.sh"; path_prepend_ ./src 21print_ver_ tail 22 23grep '^#define HAVE_INOTIFY 1' "$CONFIG_HEADER" >/dev/null \ 24 && HAVE_INOTIFY=1 25 26inotify_failed_re='inotify (resources exhausted|cannot be used)' 27 28touch here || framework_failure_ 29{ touch unreadable && chmod a-r unreadable; } || framework_failure_ 30 31# Terminate any background tail process 32cleanup_() { kill $pid 2>/dev/null && wait $pid; } 33 34# speedup non inotify case 35fastpoll='-s.1 --max-unchanged-stats=1' 36 37for mode in '' '---disable-inotify'; do 38 returns_ 124 timeout 10 tail $fastpoll -f $mode not_here && fail=1 39 40 if test ! -r unreadable; then # can't test this when root 41 returns_ 124 timeout 10 tail $fastpoll -f $mode unreadable && fail=1 42 fi 43 44 returns_ 124 timeout .1 tail $fastpoll -f $mode here 2>tail.err || fail=1 45 46 # 'tail -F' must wait in any case. 47 48 returns_ 124 timeout .1 tail $fastpoll -F $mode here 2>>tail.err || fail=1 49 50 if test ! -r unreadable; then # can't test this when root 51 returns_ 124 timeout .1 tail $fastpoll -F $mode unreadable || fail=1 52 fi 53 54 returns_ 124 timeout .1 tail $fastpoll -F $mode not_here || fail=1 55 56 grep -Ev "$inotify_failed_re" tail.err > x 57 mv x tail.err 58 compare /dev/null tail.err || fail=1 59 >tail.err 60done 61 62if test "$HAVE_INOTIFY" && test -z "$mode" && is_local_dir_ .; then 63 # Ensure -F never follows a descriptor after rename 64 # either with tiny or significant delays between operations 65 tail_F() 66 { 67 local delay="$1" 68 69 > k && > tail.out && > tail.err || framework_failure_ 70 tail $fastpoll -F $mode k >tail.out 2>tail.err & pid=$! 71 sleep $delay 72 mv k l 73 sleep $delay 74 touch k 75 mv k l 76 sleep $delay 77 echo NO >> l 78 sleep $delay 79 cleanup_ 80 rm -f k l 81 82 test -s tail.out \ 83 && ! grep -E "$inotify_failed_re" tail.err >/dev/null 84 } 85 86 retry_delay_ tail_F 0 1 && { cat tail.out; fail=1; } 87 retry_delay_ tail_F .2 1 && { cat tail.out; fail=1; } 88fi 89 90Exit $fail 91