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Diffstat (limited to '')
| -rwxr-xr-x | tests/tail-2/symlink.sh | 94 |
1 files changed, 94 insertions, 0 deletions
diff --git a/tests/tail-2/symlink.sh b/tests/tail-2/symlink.sh new file mode 100755 index 0000000..c8392f6 --- /dev/null +++ b/tests/tail-2/symlink.sh @@ -0,0 +1,94 @@ +#!/bin/sh +# Ensure tail tracks symlinks properly. + +# Copyright (C) 2013-2020 Free Software Foundation, Inc. + +# This program is free software: you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published by +# the Free Software Foundation, either version 3 of the License, or +# (at your option) any later version. + +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. + +# You should have received a copy of the GNU General Public License +# along with this program. If not, see <https://www.gnu.org/licenses/>. + +. "${srcdir=.}/tests/init.sh"; path_prepend_ ./src +print_ver_ tail + +# Function to count number of lines from tail +# while ignoring transient errors due to resource limits +countlines_ () +{ + grep -Ev 'inotify (resources exhausted|cannot be used)' out | wc -l +} + +# Function to check the expected line count in 'out'. +# Called via retry_delay_(). Sleep some time - see retry_delay_() - if the +# line count is still smaller than expected. +wait4lines_ () +{ + local delay=$1 + local elc=$2 # Expected line count. + [ "$(countlines_)" -ge "$elc" ] || { sleep $delay; return 1; } +} + +# Terminate any background tail process +cleanup_() { kill $pid 2>/dev/null && wait $pid; } + +# speedup non inotify case +fastpoll='-s.1 --max-unchanged-stats=1' + +# Ensure changing targets of cli specified symlinks are handled. +# Prior to v8.22, inotify would fail to recognize changes in the targets. +# Clear 'out' so that we can check its contents without races. +>out || framework_failure_ +ln -nsf target symlink || framework_failure_ +timeout 10 tail $fastpoll -F symlink >out 2>&1 & pid=$! +# Wait for "cannot open..." +retry_delay_ wait4lines_ .1 6 1 || { cat out; fail=1; } +echo "X" > target || framework_failure_ +# Wait for the expected output. +retry_delay_ wait4lines_ .1 6 3 || { cat out; fail=1; } +cleanup_ +# Expect 3 lines in the output file. +[ "$(countlines_)" = 3 ] || { fail=1; cat out; } +grep -F 'cannot open' out || { fail=1; cat out; } +grep -F 'has appeared' out || { fail=1; cat out; } +grep '^X$' out || { fail=1; cat out; } +rm -f target out || framework_failure_ + +# Ensure we correctly handle the source symlink itself changing. +# I.e., that we don't operate solely on the targets. +# Clear 'out' so that we can check its contents without races. +>out || framework_failure_ +echo "X1" > target1 || framework_failure_ +ln -nsf target1 symlink || framework_failure_ +timeout 10 tail $fastpoll -F symlink >out 2>&1 & pid=$! +# Wait for the expected output. +retry_delay_ wait4lines_ .1 6 1 || { cat out; fail=1; } +ln -nsf target2 symlink || framework_failure_ +# Wait for "become inaccess..." +retry_delay_ wait4lines_ .1 6 2 || { cat out; fail=1; } +echo "X2" > target2 || framework_failure_ +# Wait for the expected output. +retry_delay_ wait4lines_ .1 6 4 || { cat out; fail=1; } +cleanup_ +# Expect 4 lines in the output file. +[ "$(countlines_)" = 4 ] || { fail=1; cat out; } +grep -F 'become inacce' out || { fail=1; cat out; } +grep -F 'has appeared' out || { fail=1; cat out; } +grep '^X1$' out || { fail=1; cat out; } +grep '^X2$' out || { fail=1; cat out; } +rm -f target1 target2 out || framework_failure_ + +# Note other symlink edge cases are currently just diagnosed +# rather than being handled. I.e., if you specify a missing item, +# or existing file that later change to a symlink, if inotify +# is in use, you'll get a diagnostic saying that link will +# no longer be tailed. + +Exit $fail |