tests/env/env-signal-handler.sh

   1 #!/bin/sh
   2 # Test env --default-signal=PIPE feature.
   3
   4 # Copyright (C) 2019-2024 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
  20 print_ver_ env seq test timeout printf
  21 trap_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
  26 require_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:
  50 sed 's/^\(seq: write error:\) .*/\1/' err1t > err1 || framework_failure_
  51
  52 printf "1\n" > exp-out || framework_failure_
  53 printf "seq: write error:\n" > exp-err1 || framework_failure_
  54
  55 compare exp-out out1 || framework_failure_
  56 compare 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
  68 compare exp-out out2 || fail=1
  69 compare /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
  79 compare exp-out out4 || fail=1
  80 compare /dev/null err4 || fail=1
  81
  82 # env test - block signal handler
  83 env --block-signal true || fail=1
  84
  85 env_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).
 102 cat <<\EOF >exp || framework_failure_
 103 timeout: sending signal INT to command 'env'
 104 EOF
 105 env_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.
 111 cat <<\EOF >exp || framework_failure_
 112 timeout: sending signal INT to command 'env'
 113 timeout: sending signal KILL to command 'env'
 114 EOF
 115 env_opt='--ignore-signal=INT' retry_delay_ env_ignore_delay_ .1 6 || fail=1
 116 env_opt='--ignore-signal' retry_delay_ env_ignore_delay_ .1 6 || fail=1
 117
 118 # env test --list-signal-handling
 119 env --default-signal --ignore-signal=INT --list-signal-handling true \
 120   2> err8t || fail=1
 121 sed 's/(.*)/()/' err8t > err8 || framework_failure_
 122 env printf 'INT        (): IGNORE\n' > exp-err8 || framework_failure_
 123 compare exp-err8 err8 || fail=1
 124
 125
 126 Exit $fail