gzexe: optimize out a grep
[gzip.git] / zless.in
blob4638e9472af58bb27887c28461f2640dcbdefc9b
1 #!/bin/sh
3 # Copyright (C) 1998, 2002, 2006-2007, 2010-2022 Free Software Foundation, Inc.
5 # This program is free software; you can redistribute it and/or modify
6 # it under the terms of the GNU General Public License as published by
7 # the Free Software Foundation; either version 3 of the License, or
8 # (at your option) any later version.
10 # This program is distributed in the hope that it will be useful,
11 # but WITHOUT ANY WARRANTY; without even the implied warranty of
12 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 # GNU General Public License for more details.
15 # You should have received a copy of the GNU General Public License along
16 # with this program; if not, write to the Free Software Foundation, Inc.,
17 # 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
19 version="zless (gzip) @VERSION@
20 Copyright (C) 2007, 2011-2018 Free Software Foundation, Inc.
21 This is free software. You may redistribute copies of it under the terms of
22 the GNU General Public License <https://www.gnu.org/licenses/gpl.html>.
23 There is NO WARRANTY, to the extent permitted by law.
25 Written by Paul Eggert."
27 usage="Usage: $0 [OPTION]... [FILE]...
28 Like 'less', but operate on the uncompressed contents of any compressed FILEs.
30 Options are the same as for 'less'.
32 Report bugs to <bug-gzip@gnu.org>."
34 case $1 in
35 --help) printf '%s\n' "$usage" || exit 1; exit;;
36 --version) printf '%s\n' "$version" || exit 1; exit;;
37 esac
39 if test "${LESSMETACHARS+set}" != set; then
40 # Work around a bug in less 394 and earlier;
41 # it mishandles the metacharacters '$%=~'.
42 space=' '
43 tab=' '
44 newline='
46 LESSMETACHARS="$space$tab$newline'"';*?"()<>[|&^`#\$%=~'
47 export LESSMETACHARS
50 less_version=`less -V 2>/dev/null`
51 case $less_version in
52 less' '45[1-9]* | \
53 less' '4[6-9][0-9]* | \
54 less' '[5-9][0-9][0-9]* | \
55 less' '[1-9][0-9][0-9][0-9]*)
56 check_exit_status='|';;
57 *) check_exit_status='';;
58 esac
59 case $less_version in
60 less' '429* | \
61 less' '4[3-9][0-9]* | \
62 less' '[5-9][0-9][0-9]* | \
63 less' '[1-9][0-9][0-9][0-9]*)
64 use_input_pipe_on_stdin='-';;
65 *) use_input_pipe_on_stdin='';;
66 esac
68 LESSOPEN="|$check_exit_status${use_input_pipe_on_stdin}'gzip' -cdfq -- %s"
69 export LESSOPEN
71 exec less "$@"