# HG changeset patch # User Steve Losh # Date 1389738357 18000 # Node ID 579ee6ce9270ac924ab9a7443319621e0599fb5c # Parent a328ffc74b484a94bf3aaff3c1dc70b4eb938cd2 more diff -r a328ffc74b48 -r 579ee6ce9270 bin/bencode --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/bin/bencode Tue Jan 14 17:25:57 2014 -0500 @@ -0,0 +1,145 @@ +#!/usr/bin/env python +# The contents of this file are subject to the BitTorrent Open Source License +# Version 1.1 (the License). You may not copy or use this file, in either +# source code or executable form, except in compliance with the License. You +# may obtain a copy of the License at http://www.bittorrent.com/license/. +# +# Software distributed under the License is distributed on an AS IS basis, +# WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License +# for the specific language governing rights and limitations under the +# License. + +# Written by Petru Paler + +class BTFailure(Exception): + pass + + +def decode_int(x, f): + f += 1 + newf = x.index('e', f) + n = int(x[f:newf]) + if x[f] == '-': + if x[f + 1] == '0': + raise ValueError + elif x[f] == '0' and newf != f+1: + raise ValueError + return (n, newf+1) + +def decode_string(x, f): + colon = x.index(':', f) + n = int(x[f:colon]) + if x[f] == '0' and colon != f+1: + raise ValueError + colon += 1 + return (x[colon:colon+n], colon+n) + +def decode_list(x, f): + r, f = [], f+1 + while x[f] != 'e': + v, f = decode_func[x[f]](x, f) + r.append(v) + return (r, f + 1) + +def decode_dict(x, f): + r, f = {}, f+1 + while x[f] != 'e': + k, f = decode_string(x, f) + r[k], f = decode_func[x[f]](x, f) + return (r, f + 1) + +decode_func = {} +decode_func['l'] = decode_list +decode_func['d'] = decode_dict +decode_func['i'] = decode_int +decode_func['0'] = decode_string +decode_func['1'] = decode_string +decode_func['2'] = decode_string +decode_func['3'] = decode_string +decode_func['4'] = decode_string +decode_func['5'] = decode_string +decode_func['6'] = decode_string +decode_func['7'] = decode_string +decode_func['8'] = decode_string +decode_func['9'] = decode_string + +def bdecode(x): + try: + r, l = decode_func[x[0]](x, 0) + except (IndexError, KeyError, ValueError): + raise BTFailure("not a valid bencoded string") + if l != len(x): + raise BTFailure("invalid bencoded value (data after valid prefix)") + return r + +from types import StringType, IntType, LongType, DictType, ListType, TupleType + + +class Bencached(object): + + __slots__ = ['bencoded'] + + def __init__(self, s): + self.bencoded = s + +def encode_bencached(x,r): + r.append(x.bencoded) + +def encode_int(x, r): + r.extend(('i', str(x), 'e')) + +def encode_bool(x, r): + if x: + encode_int(1, r) + else: + encode_int(0, r) + +def encode_string(x, r): + r.extend((str(len(x)), ':', x)) + +def encode_list(x, r): + r.append('l') + for i in x: + encode_func[type(i)](i, r) + r.append('e') + +def encode_dict(x,r): + r.append('d') + ilist = x.items() + ilist.sort() + for k, v in ilist: + r.extend((str(len(k)), ':', k)) + encode_func[type(v)](v, r) + r.append('e') + +encode_func = {} +encode_func[Bencached] = encode_bencached +encode_func[IntType] = encode_int +encode_func[LongType] = encode_int +encode_func[StringType] = encode_string +encode_func[ListType] = encode_list +encode_func[TupleType] = encode_list +encode_func[DictType] = encode_dict + +try: + from types import BooleanType + encode_func[BooleanType] = encode_bool +except ImportError: + pass + +def bencode(x): + r = [] + encode_func[type(x)](x, r) + return ''.join(r) + +if __name__ == '__main__': + import sys, pprint + + line = sys.stdin.readline() + while line: + try: + pprint.pprint(bdecode(line.strip())) + except: + sys.stdout.write(line) + sys.stdout.flush() + line = sys.stdin.readline()