#!/usr/bin/perl -w
use strict;
# (C) 2003-2007 Willem Jan Hengeveld <itsme@xs4all.nl>
# Web: http://www.xs4all.nl/~itsme/
#      http://wiki.xda-developers.com/
#
# $Id: crc32 1502 2007-04-15 07:54:20Z itsme $
#
# computes and prints to stdout the CRC-32 values of the given files
use Archive::Zip;
use XdaDevelopers::NbfUtils;
use IO::File;
use Getopt::Long;
my $initialvalue=0;
my $negate_value=0;
my $lib=0;

GetOptions(
    "i=s" => sub { $initialvalue= eval($_[1]); },
    "n"   => \$negate_value,
    "z"   => \$lib,
) or die usage();
sub usage {
    print "Usage: crc32 [-i Initialvalue]  [-n]  [files]\n";
    print "    -i  : specify value other than 0\n";
    print "    -n  : negate result and initial value\n";
    print "    -z  : use zip lib crc\n";
}

if (@ARGV) {
    my $totalFiles = scalar(@ARGV);
    foreach my $file (@ARGV)
    {
        processfile($file, $totalFiles>1);
    }
}
else {
    processfile("-");
}

exit(0);

sub processfile {
    my ($file, $printnames)= @_;

	if (-d $file)
	{
		warn "$0: ${file}: Is a directory\n";
		return;
	}
	my $fh = IO::File->new();
    if ($file ne "-") {
        if (! $fh->open($file, 'r'))
        {
            warn "$0: '$file' - $!\n";
            return;
        }
    }
    else {
        $fh->fdopen(fileno(STDIN), "r");
    }
	binmode($fh);
	my $buffer;
	my $bytesRead;
	my $crc = $initialvalue;
    $crc = ~$crc  if ($negate_value);
	while ($bytesRead = $fh->read($buffer, 32768))
	{
        if ($lib) {
            $crc = Archive::Zip::computeCRC32($buffer, $crc);
        }
        else {
            $crc = XdaDevelopers::NbfUtils::crc32($buffer, $crc);
        }
	}
    $crc = ~$crc  if ($negate_value);

	printf("%08x", $crc);
	print("\t$file") if ($printnames);
	print("\n");
}