--- /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()