blob: 72cd6624ebe00937241f8f89a2b4e9b51f444132 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
|
package Crypt::Checksum::CRC32;
use strict;
use warnings;
our $VERSION = '0.048';
use Carp;
use CryptX;
sub addfile {
my ($self, $file) = @_;
my $handle;
if (ref(\$file) eq 'SCALAR') { #filename
open($handle, "<", $file) || croak "FATAL: cannot open '$file': $!";
binmode($handle);
}
else { #handle
$handle = $file
}
croak "FATAL: invalid handle" unless defined $handle;
my $n;
my $buf = "";
while (($n = read($handle, $buf, 32*1024))) {
$self->add($buf)
}
croak "FATAL: read failed: $!" unless defined $n;
return $self;
}
sub CLONE_SKIP { 1 } # prevent cloning
1;
=pod
=head1 NAME
Crypt::Checksum::CRC32 - Compute CRC32 checksum
=head1 SYNOPSIS
use Crypt::Checksum::CRC32;
$d = Crypt::Checksum::CRC32->new;
$d->add('any data');
$d->addfile('filename.dat');
$d->addfile(*FILEHANDLE);
$checksum_raw = $d->digest; # raw bytes
$checksum_hex = $d->hexdigest; # hexadecimal form
=head1 DESCRIPTION
Calculating CRC32 checksums (OO interface);
I<Since: CryptX-0.032>
=head1 METHODS
=head2 new
Constructor, returns a reference to the checksum object.
$d = Crypt::Checksum::CRC32->new;
=head2 clone
Creates a copy of the checksum object state and returns a reference to the copy.
$d->clone();
=head2 reset
Reinitialize the checksum object state and returns a reference to the checksum object.
$d->reset();
=head2 add
All arguments are appended to the message we calculate checksum for.
The return value is the checksum object itself.
$d->add('any data');
#or
$d->add('any data', 'more data', 'even more data');
=head2 addfile
The content of the file (or filehandle) is appended to the message we calculate checksum for.
The return value is the checksum object itself.
$d->addfile('filename.dat');
#or
$d->addfile(*FILEHANDLE);
B<BEWARE:> You have to make sure that the filehandle is in binary mode before you pass it as argument to the addfile() method.
=head2 digest
Returns the binary checksum (raw bytes).
$result_raw = $d->digest();
=head2 hexdigest
Returns the checksum encoded as a hexadecimal string.
$result_hex = $d->hexdigest();
=head1 SEE ALSO
=over
=item * L<CryptX|CryptX>, L<Crypt::Checksum>
=item * L<https://en.wikipedia.org/wiki/Cyclic_redundancy_check>
=back
=cut
|
