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

# Copyright (C) 1998, 2002, 2006, 2007 Free Software Foundation
# Copyright (C) 1993 Jean-loup Gailly

# 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.

# shellcheck shell=sh disable=SC1003,SC2016

@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. With gzip, bzip2, and lzop it's OK to just unset the
# environment variables.
xz='@xz@ --format=auto'
unset GZIP BZIP BZIP2 LZOP

case ${0##*/} in
  *cmp*) prog=xzcmp; cmp=${CMP:-cmp};;
  *)     prog=xzdiff; cmp=${DIFF:-diff};;
esac

version="$prog (@PACKAGE_NAME@) @PACKAGE_VERSION@"

usage="Usage: ${0##*/} [OPTION]... FILE1 [FILE2]
Compare FILE1 to FILE2, using their uncompressed contents if they are
compressed.  If FILE2 is omitted, then the files compared are FILE1 and
FILE1 from which the compression format suffix has been stripped.

Do comparisons like '$cmp' does.  OPTIONs are the same as for '$cmp'.

Report bugs to <@PACKAGE_BUGREPORT@>."

# sed script to escape all ' for the shell, and then (to handle trailing
# newlines correctly) turn trailing X on last line into '.
escape='
  s/'\''/'\''\\'\'''\''/g
  $s/X$/'\''/
'

while :; do
  case $1 in
    --h*) printf '%s\n' "$usage" || exit 2; exit;;
    --v*) printf '%s\n' "$version" || exit 2; exit;;
    --) shift; break;;
    -*\'*) cmp="$cmp '"`printf '%sX\n' "$1" | sed "$escape"`;;
    -?*) cmp="$cmp '$1'";;
    *) break;;
  esac
  shift
done
cmp="$cmp --"

for file; do
  test "X$file" = X- || true < "$file" || exit 2
done

# xz needs -qQ to ignore warnings like unsupported check type.
xz1="$xz -qQ"
xz2="$xz -qQ"
xz_status=0
exec 3>&1

if test $# -eq 1; then
  case $1 in
    *[-.]xz | *[-.]lzma | *[-.]lz | *.t[lx]z)
      ;;
    *[-.]bz2 | *.tbz | *.tbz2)
      xz1=bzip2;;
    *[-.][zZ] | *_z | *[-.]gz | *.t[ag]z)
      xz1=gzip;;
    *[-.]lzo | *.tzo)
      xz1=lzop;;
    *[-.]zst | *.tzst)
      xz1='zstd -q';;
    *[-.]lz4)
      xz1=lz4;;
    *)
      printf '%s\n' "$0: $1: Unknown compressed file name suffix" >&2
      exit 2;;
  esac
  # The FILE variable is used with eval, and shellcheck doesn't see that.
  # shellcheck disable=SC2034
  case $1 in
    *[-.][zZ] | *_z | *[-.][gx]z | *[-.]bz2 | *[-.]lzma | *[-.]lz | *[-.]lzo | *[-.]zst | *[-.]lz4)
      FILE=`expr "X$1" : 'X\(.*\)[-.][abglmostxzZ24]*$'`;;
    *.t[abglx]z)
      FILE=`expr "X$1" : 'X\(.*[-.]t\)[abglx]z$'`ar;;
    *.tbz2)
      FILE=`expr "X$1" : 'X\(.*[-.]t\)bz2$'`ar;;
    *.tzo)
      FILE=`expr "X$1" : 'X\(.*[-.]t\)zo$'`ar;;
    *.tzst)
      FILE=`expr "X$1" : 'X\(.*[-.]t\)zst$'`ar;;
  esac
  xz_status=$(
    exec 4>&1
    ($xz1 -cd -- "$1" 4>&-; echo $? >&4) 3>&- | eval "$cmp" - '"$FILE"' >&3
  )
elif test $# -eq 2; then
  case $1 in
    *[-.]bz2 | *.tbz | *.tbz2) xz1=bzip2;;
    *[-.][zZ] | *_z | *[-.]gz | *.t[ag]z) xz1=gzip;;
    *[-.]lzo | *.tzo) xz1=lzop;;
    *[-.]zst | *.tzst) xz1='zstd -q';;
    *[-.]lz4) xz1=lz4;;
  esac
  case $2 in
    *[-.]bz2 | *.tbz | *.tbz2) xz2=bzip2;;
    *[-.][zZ] | *_z | *[-.]gz | *.t[ag]z) xz2=gzip;;
    *[-.]lzo | *.tzo) xz2=lzop;;
    *[-.]zst | *.tzst) xz2='zstd -q';;
    *[-.]lz4) xz2=lz4;;
  esac
  case $1 in
    *[-.][zZ] | *_z | *[-.][gx]z | *[-.]bz2 | *[-.]lzma | *[-.]lz | *.t[abglx]z | *.tbz2 | *[-.]lzo | *.tzo | *[-.]zst | *.tzst | *[-.]lz4 | -)
      case "$2" in
        *[-.][zZ] | *_z | *[-.][gx]z | *[-.]bz2 | *[-.]lzma | *[-.]lz | *.t[abglx]z | *.tbz2 | *[-.]lzo | *.tzo | *[-.]zst | *.tzst | *[-.]lz4 | -)
          if test "$1$2" = --; then
            xz_status=$(
              exec 4>&1
              ($xz1 -cdf - 4>&-; echo $? >&4) 3>&- |
                eval "$cmp" - - >&3
            )
          elif # Reject Solaris 8's buggy /bin/bash 2.03.
              echo X | (echo X | eval "$cmp" /dev/fd/5 - >/dev/null 2>&1) 5<&0; then
            # NOTE: xz_status will contain two numbers.
            xz_status=$(
              exec 4>&1
              ($xz1 -cdf -- "$1" 4>&-; echo $? >&4) 3>&- |
                ( ($xz2 -cdf -- "$2" 4>&-; echo $? >&4) 3>&- 5<&- </dev/null |
                eval "$cmp" /dev/fd/5 - >&3) 5<&0
            )
          else
            F=`expr "/$2" : '.*/\(.*\)[-.][ablmotxz2]*$'` || F=$prog
            tmp=
            trap '
              test -n "$tmp" && rm -rf "$tmp"
              (exit 2); exit 2
            ' HUP INT PIPE TERM 0
            if type mktemp >/dev/null 2>&1; then
              # Note that FreeBSD's mktemp isn't fully compatible with
              # the implementations from mktemp.org and GNU coreutils.
              # It is important that the -t argument is the last argument
              # and that no "--" is used between -t and the template argument.
              # This way this command works on all implementations.
              tmp=`mktemp -d -t "$prog.XXXXXXXXXX"` || exit 2
            else
              # Fallback code if mktemp is missing. This isn't as
              # robust as using mktemp since this doesn't try with
              # different file names in case of a file name conflict.
              #
              # There's no need to save the original umask since
              # we don't create any non-temp files. Note that using
              # mkdir -m 0077 isn't secure since some mkdir implementations
              # create the dir with the default umask and chmod the
              # the dir afterwards.
              umask 0077
              mkdir -- "${TMPDIR-/tmp}/$prog.$$" || exit 2
              tmp="${TMPDIR-/tmp}/$prog.$$"
            fi
            $xz2 -cdf -- "$2" > "$tmp/$F" || exit 2
            xz_status=$(
              exec 4>&1
              ($xz1 -cdf -- "$1" 4>&-; echo $? >&4) 3>&- |
                eval "$cmp" - '"$tmp/$F"' >&3
            )
            cmp_status=$?
            rm -rf "$tmp" || xz_status=$?
            trap - HUP INT PIPE TERM 0
            (exit $cmp_status)
          fi;;
      *)
        xz_status=$(
          exec 4>&1
          ($xz1 -cdf -- "$1" 4>&-; echo $? >&4) 3>&- |
            eval "$cmp" - '"$2"' >&3
        );;
    esac;;
  *)
    case "$2" in
      *[-.][zZ] | *_z | *[-.][gx]z | *[-.]bz2 | *[-.]lzma | *[-.]lz | *.t[abglx]z | *.tbz2 | *[-.]lzo | *.tzo | *[-.]zst | *.tzst | *[-.]lz4 | -)
        xz_status=$(
          exec 4>&1
          ($xz2 -cdf -- "$2" 4>&-; echo $? >&4) 3>&- |
            eval "$cmp" '"$1"' - >&3
         );;
      *)
        eval "$cmp" '"$1"' '"$2"';;
    esac;;
  esac
else
  printf '%s\n' "$0: Invalid number of operands; try '${0##*/} --help' for help" >&2
  exit 2
fi

cmp_status=$?
for num in $xz_status ; do
  # 0 from decompressor means successful decompression. SIGPIPE from
  # decompressor is possible when diff or cmp exits before the whole file
  # has been decompressed. In that case we want to retain the exit status
  # from diff or cmp. Note that using "trap '' PIPE" is not possible
  # because gzip changes its behavior (including exit status) if SIGPIPE
  # is ignored.
  test "$num" -eq 0 && continue
  test "$num" -ge 128 \
      && test "$(kill -l "$num" 2> /dev/null)" = "PIPE" \
      && continue
  exit 2
done
exit $cmp_status
