NAME¶
Bencode - BitTorrent serialisation format
VERSION¶
version 1.4
SYNOPSIS¶
use Bencode qw( bencode bdecode );
my $bencoded = bencode { 'age' => 25, 'eyes' => 'blue' };
print $bencoded, "\n";
my $decoded = bdecode $bencoded;
DESCRIPTION¶
This module implements the BitTorrent
bencode serialisation format as
described in <
http://www.bittorrent.org/protocol.html>.
INTERFACE¶
"bencode( $datastructure )"¶
Takes a single argument which may be a scalar or a reference to a scalar, array
or hash. Arrays and hashes may in turn contain values of these same types.
Simple scalars that look like canonically represented integers will be
serialised as such. To bypass the heuristic and force serialisation as a
string, use a reference to a scalar.
Croaks on unhandled data types.
"bdecode( $string [, $do_lenient_decode [, $max_depth ] ]
)"¶
Takes a string and returns the corresponding deserialised data structure.
If you pass a true value for the second option, it will disregard the sort order
of dict keys. This violation of the
bencode format is somewhat common.
If you pass an integer for the third option, it will croak when attempting to
parse dictionaries nested deeper than this level, to prevent DoS attacks using
maliciously crafted input.
Croaks on malformed data.
DIAGNOSTICS¶
- "trailing garbage at %s"
- Your data does not end after the first
bencode-serialised item.
You may also get this error if a malformed item follows.
- "garbage at %s"
- Your data is malformed.
- "unexpected end of data at %s"
- Your data is truncated.
- "unexpected end of string data starting at
%s"
- Your data includes a string declared to be longer than the
available data.
- "malformed string length at %s"
- Your data contained a string with negative length or a
length with leading zeroes.
- "malformed integer data at %s"
- Your data contained something that was supposed to be an
integer but didn't make sense.
- "dict key not in sort order at %s"
- Your data violates the bencode format constaint that
dict keys must appear in lexical sort order.
- "duplicate dict key at %s"
- Your data violates the bencode format constaint that
all dict keys must be unique.
- "dict key is not a string at %s"
- Your data violates the bencode format constaint that
all dict keys be strings.
- "dict key is missing value at %s"
- Your data contains a dictionary with an odd number of
elements.
- "nesting depth exceeded at %s"
- Your data contains dicts or lists that are nested deeper
than the $max_depth passed to "bdecode()".
- "unhandled data type"
- You are trying to serialise a data structure that consists
of data types other than
- •
- scalars
- •
- references to arrays
- •
- references to hashes
- •
- references to scalars
The format does not support this.
BUGS AND LIMITATIONS¶
Strings and numbers are practically indistinguishable in Perl, so
"bencode()" has to resort to a heuristic to decide how to serialise
a scalar. This cannot be fixed.
Please report any bugs or feature requests through the web interface at
<
http://github.com/ap/Bencode/issues>.
AUTHOR¶
Aristotle Pagaltzis <pagaltzis@gmx.de>
COPYRIGHT AND LICENSE¶
This software is copyright (c) 2010 by Aristotle Pagaltzis.
This is free software; you can redistribute it and/or modify it under the same
terms as the Perl 5 programming language system itself.