1#!/bin/sh
2# Test whether sort avoids opening more file descriptors than it is
3# allowed when merging files.
4
5# Copyright (C) 2009-2023 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_ sort
22
23mkdir in err || framework_failure_
24
25
26for i in $(seq 17); do
27  echo $i >in/$i
28done
29seq 17 >some-data
30
31# When these tests are run inside the automated testing framework, they
32# have one less available file descriptor than when run outside the
33# automated testing framework. If a test with a batch size of b fails
34# inside the ATF, then the same test with batch size b+1 may pass outside
35# the ATF but fail inside it.
36
37# The default batch size (nmerge) is 16.
38(ulimit -n 19 \
39   && sort -m --batch-size=16 in/* 2>err/merge-default-err \
40   || ! grep "open failed" err/merge-default-err) || fail=1
41
42# If sort opens a file to sort by random hashes of keys,
43# it needs to consider this file against its limit on open file
44# descriptors.  Test once with the default random source
45# and once with an explicit source.
46for randsource in '' --random-source=some-data; do
47  (ulimit -n 20 \
48     && sort -mR $randsource --batch-size=16 in/* 2>err/merge-random-err \
49     || ! grep "open failed" err/merge-random-err) || fail=1
50done
51
52# 'sort -m' should work in a limited file descriptor
53# environment when the output is repeatedly one of its inputs.
54# In coreutils 8.7 and earlier, 'sort' would dump core on this test.
55#
56# This test uses 'exec' to redirect file descriptors rather than
57# ordinary redirection on the 'sort' command.  This is intended to
58# work around bugs in OpenBSD /bin/sh, and some other sh variants,
59# that squirrel away file descriptors before closing them; see
60# <https://lists.gnu.org/r/bug-tar/2010-10/msg00075.html>.
61# This test finds the bug only with shells that do not close FDs on
62# exec, and will miss the bug (if present) on other shells, but it's
63# not easy to fix this without running afoul of the OpenBSD-like sh bugs.
64#
65# This script uses 'ulimit -n 10' with 7, 8 and 9 open
66# to limit 'sort' to at most 7 open files:
67# stdin, stdout, stderr, two input and one output files when merging,
68# and an extra.  The extra is for old-fashioned platforms like Solaris 10
69# where opening a temp file also requires opening /dev/urandom to
70# calculate the temp file's name.
71(seq 6 && echo 6) >exp || framework_failure_
72echo 6 >out || framework_failure_
73(exec 3<&- 4<&- 5<&- 6<&- 7</dev/null 8<&7 9<&7 &&
74 ulimit -n 10 &&
75 sort -n -m --batch-size=7 -o out out in/1 in/2 in/3 in/4 in/5 out
76) &&
77compare exp out || fail=1
78
79Exit $fail
80