1#!/bin/sh
2# Test env --default-signal=PIPE feature.
3
4# Copyright (C) 2019-2023 Free Software Foundation, Inc.
5
6# This program is free software: you can redistribute it and/or modify
7# it under the terms of the GNU General Public License as published by
8# the Free Software Foundation, either version 3 of the License, or
9# (at your option) any later version.
10
11# This program is distributed in the hope that it will be useful,
12# but WITHOUT ANY WARRANTY; without even the implied warranty of
13# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14# GNU General Public License for more details.
15
16# You should have received a copy of the GNU General Public License
17# along with this program.  If not, see <https://www.gnu.org/licenses/>.
18
19. "${srcdir=.}/tests/init.sh"; path_prepend_ ./src
20print_ver_ env seq test timeout printf
21trap_sigpipe_or_skip_
22
23# /bin/sh has an intermittent failure in ignoring SIGPIPE on OpenIndiana 11
24# so we require bash as discussed at:
25# https://lists.gnu.org/archive/html/coreutils/2020-03/msg00004.html
26require_bash_as_SHELL_
27
28# Paraphrasing https://bugs.gnu.org/34488#8:
29# POSIX requires that sh started with an inherited ignored SIGPIPE must
30# silently ignore all attempts from within the shell to restore SIGPIPE
31# handling to child processes of the shell:
32#
33#    $ (trap '' PIPE; bash -c 'trap - PIPE; seq inf | head -n1')
34#    1
35#    seq: write error: Broken pipe
36#
37# With 'env --default-signal=PIPE', the signal handler can be reset to its
38# default.
39
40# Baseline Test - default signal handler
41# --------------------------------------
42# Ensure this results in a "broken pipe" error (the first 'trap'
43# sets SIGPIPE to ignore, and the second 'trap' becomes a no-op instead
44# of resetting SIGPIPE to its default). Upon a SIGPIPE 'seq' will not be
45# terminated, instead its write(2) call will return an error.
46(trap '' PIPE; $SHELL -c 'trap - PIPE; seq 999999 2>err1t | head -n1 > out1')
47
48# The exact broken pipe message depends on the operating system, just ensure
49# there was a 'write error' message in stderr:
50sed 's/^\(seq: write error:\) .*/\1/' err1t > err1 || framework_failure_
51
52printf "1\n" > exp-out || framework_failure_
53printf "seq: write error:\n" > exp-err1 || framework_failure_
54
55compare exp-out out1 || framework_failure_
56compare exp-err1 err1 || framework_failure_
57
58
59# env test - default signal handler
60# ---------------------------------
61# With env resetting the signal handler to its defaults, there should be no
62# error message (because the default SIGPIPE action is to terminate the
63# 'seq' program):
64(trap '' PIPE;
65 env --default-signal=PIPE \
66    $SHELL -c 'trap - PIPE; seq 999999 2>err2 | head -n1 > out2')
67
68compare exp-out out2 || fail=1
69compare /dev/null err2 || fail=1
70
71# env test - default signal handler (3)
72# -------------------------------------
73# Repeat the previous test, using --default-signal with no signal names,
74# i.e., all signals.
75(trap '' PIPE;
76 env --default-signal \
77    $SHELL -c 'trap - PIPE; seq 999999 2>err4 | head -n1 > out4')
78
79compare exp-out out4 || fail=1
80compare /dev/null err4 || fail=1
81
82# env test - block signal handler
83env --block-signal true || fail=1
84
85env_ignore_delay_()
86{
87  local delay="$1"
88
89  # The first 'env' is just to ensure timeout is not a shell built-in.
90  env timeout --verbose --kill-after=.1 --signal=INT $delay \
91    env $env_opt sleep 10 > /dev/null 2>outt
92  # check only the first two lines from stderr, which are printed by timeout.
93  # (operating systems might add more messages, like "killed").
94  sed -n '1,2p' outt > out || framework_failure_
95  compare exp out
96}
97
98# Baseline test - ignore signal handler
99# -------------------------------------
100# Terminate 'sleep' with SIGINT
101# (SIGINT's default action is to terminate a program).
102cat <<\EOF >exp || framework_failure_
103timeout: sending signal INT to command 'env'
104EOF
105env_opt='' retry_delay_ env_ignore_delay_ .1 6 || fail=1
106
107# env test - ignore signal handler
108# --------------------------------
109# Use env to ignore SIGINT - "sleep" should continue running
110# after timeout sends SIGINT, and be killed using SIGKILL.
111cat <<\EOF >exp || framework_failure_
112timeout: sending signal INT to command 'env'
113timeout: sending signal KILL to command 'env'
114EOF
115env_opt='--ignore-signal=INT' retry_delay_ env_ignore_delay_ .1 6 || fail=1
116env_opt='--ignore-signal' retry_delay_ env_ignore_delay_ .1 6 || fail=1
117
118# env test --list-signal-handling
119env --default-signal --ignore-signal=INT --list-signal-handling true \
120  2> err8t || fail=1
121sed 's/(.*)/()/' err8t > err8 || framework_failure_
122env printf 'INT        (): IGNORE\n' > exp-err8 || framework_failure_
123compare exp-err8 err8 || fail=1
124
125
126Exit $fail
127