xz/src/scripts/xzless.in

#!@POSIX_SHELL@
# SPDX-License-Identifier: GPL-2.0-or-later

# Copyright (C) 1998, 2002, 2006, 2007 Free Software Foundation

# The original version for gzip was written by Paul Eggert.
# Modified for XZ Utils by Andrew Dudman and Lasse Collin.

# 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 2 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.

@enable_path_for_scripts@
#SET_PATH - This line is a placeholder to ease patching this script.

# Instead of unsetting XZ_OPT, just make sure that xz will use file format
# autodetection. This way memory usage limit and thread limit can be
# specified via XZ_OPT.
xz='@xz@ --format=auto'

version='xzless (@PACKAGE_NAME@) @VERSION@'

usage="Usage: ${0##*/} [OPTION]... [FILE]...
Like 'less', but operate on the uncompressed contents of xz compressed FILEs.

Options are the same as for 'less'.

Report bugs to <@PACKAGE_BUGREPORT@>."

case $1 in
	--help)    printf '%s\n' "$usage" || exit 2; exit;;
	--version) printf '%s\n' "$version" || exit 2; exit;;
esac

if test "${LESSMETACHARS+set}" != set; then
	# Work around a bug in less 394 and earlier;
	# it mishandles the metacharacters '$%=~'.
	space=' '
	tab='	'
	nl='
'
	LESSMETACHARS="$space$tab$nl'"';*?"()<>[|&^`#\$%=~'
fi

VER=$(less -V | { read _ ver _ && echo ${ver%%.*}; })
if test "$VER" -ge 451; then
	# less 451 or later: If the compressed file is valid but has
	# zero bytes of uncompressed data, using two vertical bars ||- makes
	# "less" check the exit status of xz and if it is zero then display
	# an empty file. With a single vertical bar |- and no output from xz,
	# "less" would attempt to display the raw input file instead.
	LESSOPEN="||-$xz -cdfqQ -- %s"
elif test "$VER" -ge 429; then
	# less 429 or later: LESSOPEN pipe will be used on
	# standard input if $LESSOPEN begins with |-.
	LESSOPEN="|-$xz -cdfqQ -- %s"
else
	LESSOPEN="|$xz -cdfqQ -- %s"
fi

SHOW_PREPROC_ERRORS=
if test "$VER" -ge 632; then
	SHOW_PREPROC_ERRORS=--show-preproc-errors
fi

export LESSMETACHARS LESSOPEN

exec less $SHOW_PREPROC_ERRORS "$@"