:
    eval 'exec perl -S $0 ${1+"$@"}'
        if 0;
#
# This file is part of the LibreOffice project.
#
# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
# file, You can obtain one at http://mozilla.org/MPL/2.0/.
#
# This file incorporates work covered by the following license notice:
#
#   Licensed to the Apache Software Foundation (ASF) under one or more
#   contributor license agreements. See the NOTICE file distributed
#   with this work for additional information regarding copyright
#   ownership. The ASF licenses this file to you under the Apache
#   License, Version 2.0 (the "License"); you may not use this file
#   except in compliance with the License. You may obtain a copy of
#   the License at http://www.apache.org/licenses/LICENSE-2.0 .
#


my ( $srcfile, $destfile ) = @ARGV;
my ( @srclines, @destlines );
my $dest_existing = 0;
@destlines = ();

usage() if ( ! defined $srcfile || ! defined $destfile);

open(SRCFILE, "$srcfile") or die "ERROR: Can't open $srcfile\n";
@srclines = <SRCFILE>;
close SRCFILE;

if ( -f $destfile ) {
    open(DESTFILE, "$destfile") or die "ERROR: Can't open $destfile\n";
    @destlines = <DESTFILE>;
    close DESTFILE;
    $dest_existing = 1;
}

if ( ! check_if_lists_equal(\@srclines,  \@destlines) ) {
    print STDERR "Updating \"$destfile\".\n";
    unlink "$destfile" or die "ERROR: Can't remove old $destfile\n" if ( $dest_existing );
    rename "$srcfile", "$destfile" or die "ERROR: Can't rename $srcfile to $destfile\n";
} else {
    print STDERR "\"$destfile\" unchanged.\n";
}

sub check_if_lists_equal
{
    my  ( $srclist_ref, $destlist_ref ) = @_;
    my @srclist  = @{ $srclist_ref };
    my @destlist  = @{ $destlist_ref };
    return  0 if ( $#srclist != $#destlist );
    for ( my $i = 0; $i  < $#srclist; $i++ ) {
        return 0 if  ( $srclist[$i] ne $destlist[$i]);
    }
    return  1;
}

sub usage
{
    print STDERR "Usage: diffmv sourcefile destfile\n";
    print STDERR "Do move diffing file only\n";
    exit 1;
}