source: kBuild/trunk/src/grep/tests/write-error-msg

#!/bin/sh
# Ensure that output errors are reported with errno information.

# Copyright 2016-2021 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=.}/init.sh"; path_prepend_ ../src
test -e /dev/full || skip_ your system lacks /dev/full

export LC_ALL=C

# generate large input, filling the libc stdio buffers
# and triggering a write(2) even without line buffering.
yes 12345 | head -n 50000 > in || framework_failure_

fail=0

# disk-full error, line buffered
# (note: GNU grep returns 2 on error)
returns_ 2 grep --line-buffered -v '^$' <in >/dev/full 2>err1 \
    || framework_failure_

# disk-full error, unbuffered
# (note: GNU grep returns 2 on error)
returns_ 2 grep -v '^$' <in >/dev/full 2>err2 \
    || framework_failure_

# ensure each error message file contains a 'write error' with additional text
for f in err1 err2 ;
do
    grep -Eiq '^[^:]*: write error: [a-z]+' $f \
        || {
             warn_ "incorrect/missing error message in file $f"
             compare /dev/null $f   # print the content in the logs
             fail=1
           }
done

# These messages should be identical
compare err1 err2 \
    || { warn_ "err1,err2 contain different error messages" ; fail=1 ; }

Exit $fail