#!/bin/sh

# zgrep -- a wrapper around a grep program that decompresses files as needed
# Adapted from a version sent by Charles Levert <charles@comm.polymtl.ca>

# Copyright (C) 1998, 2001-2002, 2006-2007, 2009-2018 Free Software Foundation,
# Inc.

# Copyright (C) 1993 Jean-loup Gailly

# 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.

grep='${GREP-'\''@GREP@'\''}'

version='zgrep (gzip) @VERSION@
Copyright (C) 2010-2018 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 Jean-loup Gailly.'

usage="Usage: $0 [OPTION]... [-e] PATTERN [FILE]...
Look for instances of PATTERN in the input FILEs, using their
uncompressed contents if they are compressed.

OPTIONs are the same as for 'grep', except that the following 'grep'
options are not supported: --dereference-recursive (-R), --directories (-d),
--exclude, --exclude-from, --exclude-dir, --include, --null (-Z),
--null-data (-z), and --recursive (-r).

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

# sed script to escape all ' for the shell, and then (to handle trailing
# newlines correctly) append ' to the last line.
escape='
  s/'\''/'\''\\'\'''\''/g
  $s/$/'\''/
'
operands=
have_pat=0
files_with_matches=0
files_without_matches=0
no_filename=0
with_filename=0
pattmp=

while test $# -ne 0; do
  option=$1
  shift
  optarg=

  case $option in
  (-[0123456789EFGHIKLPRTUVZabchilnoqrsuvwxyz]*[!0123456789]*)
    arg2=-\'$(expr "X$option" : 'X-.[0-9]*\(.*\)' | sed "$escape")
    eval "set -- $arg2 "'${1+"$@"}'
    option=$(expr "X$option" : 'X\(-.[0-9]*\)');;
  (--binary-*=* | --[lm]a*=* | --reg*=*)
    ;;
  (-[ABCDXdefm] | binary-* | --file | --[lm]a* | --reg*)
    case ${1?"$option option requires an argument"} in
    (*\'*)
      optarg=" '"$(printf '%s\n' "$1" | sed "$escape");;
    (*)
      optarg=" '$1'";;
    esac
    shift;;
  (-f?*\'*)
    optarg=" '"$(expr "X$option" : 'X-f\(.*\)' | sed "$escape")
    option=-f;;
  (-f?*)
    optarg=" '"$(expr "X$option" : 'X-f\(.*\)')\'
    option=-f;;
  (--file=*\'*)
    optarg=" '"$(expr "X$option" : 'X--file=\(.*\)' | sed "$escape")
    option=--file;;
  (--file=*)
    optarg=" '"$(expr "X$option" : 'X--file=\(.*\)')\'
    option=--file;;
  (--)
    break;;
  (-?*)
    ;;
  (*)
    case $option in
    (*\'*)
      operands="$operands '"$(printf '%s\n' "$option" | sed "$escape");;
    (*)
      operands="$operands '$option'";;
    esac
    ${POSIXLY_CORRECT+break}
    continue;;
  esac

  case $option in
  (-[drRzZ] | --di* | --exc* | --inc* | --rec* | --nu*)
    printf >&2 '%s: %s: option not supported\n' "$0" "$option"
    exit 2;;
  (-e* | --reg*)
    have_pat=1;;
  (-f | --file)
    # The pattern is coming from a file rather than the command-line.
    # If the file is actually stdin then we need to do a little
    # magic, since we use stdin to pass the gzip output to grep.
    # Similarly if it is not a regular file, since it might be read repeatedly.
    # In either of these two cases, copy the pattern into a temporary file,
    # and use that file instead.  The pattern might contain null bytes,
    # so we cannot simply switch to -e here.
    if case $optarg in
       (" '-'" | " '/dev/stdin'" | " '/dev/fd/0'")
         :;;
       (*)
         eval "test ! -f$optarg";;
       esac
    then
      if test -n "$pattmp"; then
        eval "cat --$optarg" >>"$pattmp" || exit 2
        continue
      fi
      trap '
        test -n "$pattmp" && rm -f "$pattmp"
        (exit 2); exit 2
      ' HUP INT PIPE TERM 0
      case $TMPDIR in
        / | /*/) ;;
        /*) TMPDIR=$TMPDIR/;;
        *) TMPDIR=/tmp/;;
      esac
      if type mktemp >/dev/null 2>&1; then
        pattmp=$(mktemp "${TMPDIR}zgrepXXXXXXXXX") || exit 2
      else
        set -C
        pattmp=${TMPDIR}zgrep$$
      fi
      eval "cat --$optarg" >"$pattmp" || exit 2
      optarg=' "$pattmp"'
    fi
    have_pat=1;;
  (--h | --he | --hel | --help)
    printf '%s\n' "$usage" || exit 2
    exit;;
  (-H | --wi | --wit | --with | --with- | --with-f | --with-fi \
  | --with-fil | --with-file | --with-filen | --with-filena | --with-filenam \
  | --with-filename)
    with_filename=1
    continue;;
  (-l | --files-with-*)
    files_with_matches=1;;
  (-L | --files-witho*)
    files_without_matches=1;;
  (-h | --no-f*)
    no_filename=1;;
  (-V | --v | --ve | --ver | --vers | --versi | --versio | --version)
    printf '%s\n' "$version" || exit 2
    exit;;
  esac

  case $option in
  (*\'?*)
    option=\'$(printf '%s\n' "$option" | sed "$escape");;
  (*)
    option="'$option'";;
  esac

  grep="$grep $option$optarg"
done

eval "set -- $operands "'${1+"$@"}'

if test $have_pat -eq 0; then
  case ${1?"missing pattern; try \`$0 --help' for help"} in
  (*\'*)
    grep="$grep -- '"$(printf '%s\n' "$1" | sed "$escape");;
  (*)
    grep="$grep -- '$1'";;
  esac
  shift
fi

if test $# -eq 0; then
  set -- -
fi

exec 3>&1
res=1

for i
do
  # Fail if gzip or grep (or sed) fails.
  gzip_status=$(
    exec 5>&1
    (gzip -cdfq -- "$i" 5>&-; echo $? >&5) 3>&- |
    if test $files_with_matches -eq 1; then
      eval "$grep" >/dev/null && { printf '%s\n' "$i" || exit 2; }
    elif test $files_without_matches -eq 1; then
      eval "$grep" >/dev/null || {
        r=$?
        if test $r -eq 1; then
          printf '%s\n' "$i" || r=2
        fi
        test 256 -le $r && r=$(expr 128 + $r % 128)
        exit $r
      }
    elif test $with_filename -eq 0 &&
         { test $# -eq 1 || test $no_filename -eq 1; }; then
      eval "$grep"
    else
      case $i in
      (*'
'* | *'&'* | *'\'* | *'|'*)
        i=$(printf '%s\n' "$i" |
            sed '
              $!N
              $s/[&\|]/\\&/g
              $s/\n/\\n/g
            ');;
      esac
      sed_script="s|^|$i:|"

      # Fail if grep or sed fails.
      r=$(
        exec 4>&1
        (eval "$grep" 4>&-; echo $? >&4) 3>&- | sed "$sed_script" >&3 4>&-
      ) || { r=$?; test $r -lt 2 && r=2; }
      test 256 -le $r && r=$(expr 128 + $r % 128)
      exit $r
    fi >&3 5>&-
  )
  r=$?

  # Ignore gzip status 2, as it is just a warning.
  # gzip status 1 is an error, like grep status 2.
  test $gzip_status -eq 2 && gzip_status=0
  test $gzip_status -eq 1 && gzip_status=2

  # Use the more serious of the grep and gzip statuses.
  test $r -lt $gzip_status && r=$gzip_status

  # Accumulate the greatest status, except consider 0 to be greater than 1.
  if test $r -le 1 && test $res -le 1; then
     test $r -lt $res
  else
     test $res -lt $r
  fi && res=$r

  # Exit immediately on a serious error.
  test 126 -le $res && break
done

if test -n "$pattmp"; then
  rm -f "$pattmp" || {
    r=$?
    test $r -lt 2 && r=2
    test $res -lt $r && res=$r
  }
  trap - HUP INT PIPE TERM 0
fi

test 128 -le $res && kill -$(expr $res % 128) $$
exit $res
