Mini Shell

#!/bin/sh

# Copyright (C) 1998, 2002, 2006-2007, 2010-2018 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, write to the Free Software Foundation, Inc.,
# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

version="zless (gzip) 1.9
Copyright (C) 2007, 2011-2017 Free Software Foundation, Inc.
This is free software.  You may redistribute copies of it under the terms of
the GNU General Public License <https://www.gnu.org/licenses/gpl.html>.
There is NO WARRANTY, to the extent permitted by law.

Written by Paul Eggert."

usage="Usage: $0 [OPTION]... [FILE]...
Like 'less', but operate on the uncompressed contents of any compressed FILEs.

Options are the same as for 'less'.

Report bugs to <bug-gzip@gnu.org>."

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

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

less_version=`less -V 2>/dev/null`
case $less_version in
less' '45[1-9]* | \
less' '4[6-9][0-9]* | \
less' '[5-9][0-9][0-9]* | \
less' '[1-9][0-9][0-9][0-9]*)
   check_exit_status='|';;
*) check_exit_status='';;
esac
case $less_version in
less' '429* | \
less' '4[3-9][0-9]* | \
less' '[5-9][0-9][0-9]* | \
less' '[1-9][0-9][0-9][0-9]*)
   use_input_pipe_on_stdin='-';;
*) use_input_pipe_on_stdin='';;
esac

LESSOPEN="|$check_exit_status${use_input_pipe_on_stdin}gzip -cdfq -- %s"
export LESSOPEN

exec less "$@"