#!/bin/sh

# The MIT License (MIT)
#
# Copyright (c) 2026 pacman64
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.


# nullines [options...] [files...]
#
# NUL-terminated LINES ends each line with a Zero/null byte, instead of the
# usual line-feed byte. Unlike `cat`, this tool ensures no lines across inputs
# are accidentally joined, since all lines it outputs end with a null byte,
# even when the original files don't have a final line-feed byte.
#
# The options are, available both in single and double-dash versions
#
#   -h, -help    show this help message


buffered=0

case "$1" in
    -b|--b|-buffered|--buffered) buffered=1; shift ;;

    -h|--h|-help|--help)
        awk '/^# +nullines /, /^$/ { gsub(/^# ?/, ""); print }' "$0"
        exit 0
    ;;

    -) ;;

    --) shift ;;

    -*)
        printf "%s: unsupported option '%s'\n" "$0" "$1" >&2
        exit 1
    ;;
esac

# show all non-existing files given
failed=0
for arg in "$@"; do
    [ "${arg}" = "-" ] && continue
    [ -e "${arg}" ] && continue
    printf "%s: no file named \"%s\"\n" "$0" "${arg}" >&2
    failed=1
done

[ "${failed}" -gt 0 ] && exit 2

flush=0
if [ "${buffered}" -eq 0 ] && { [ -p /dev/stdout ] || [ -t 1 ]; }; then
    flush=1
fi

awk -v flush="${flush}" '
    FNR == 1 { gsub(/^\xef\xbb\xbf/, "") }

    {
        printf("%s\000", $0)
        if (flush) fflush()
    }
' "$@"