Alright, implemented encoding for the #bencode decoder. It's a really naive implementation, but moving on to the rest of the #bittorrent protocol. On to the handshakes to instantiate peer connections! :)

#Bencode uses ASCII characters as delimiters and digits.

An integer is encoded as i<integer encoded in base ten ASCII>e. Leading zeros are not allowed (although the number zero is still represented as "0"). Negative values are encoded by prefixing the number with a hyphen-minus. The number 42 would thus be encoded as i42e, 0 as i0e, and -42 as i-42e. Negative zero is not permitted.

A byte string (a sequence of bytes, not necessarily characters) is encoded as <length>:<contents>. The length is encoded in base 10, like integers, but must be non-negative (zero is allowed); the contents are just the bytes that make up the string. The string "spam" would be encoded as 4:spam. The specification does not deal with encoding of characters outside the ASCII set.

A list of values is encoded as l<contents>e . The contents consist of the bencoded elements of the list, in order, concatenated. A list consisting of the string "spam" and the number 42 would be encoded as: l4:spami42ee. Note the absence of separators between elements, and the first character is the letter 'l', not digit '1'.

A dictionary is encoded as d<contents>e. The elements of the dictionary are encoded each key immediately followed by its value. All keys must be byte strings and must appear in lexicographical order. A dictionary that associates the values 42 and "spam" with the keys "foo" and "bar", respectively (in other words, {"bar": "spam", "foo": 42}), would be encoded as follows: d3:bar4:spam3:fooi42ee.

There are no restrictions on what kind of values may be stored in lists and dictionaries; they may (and usually do) contain other lists and dictionaries. This allows for arbitrarily complex data structures to be encoded.

https://en.wikipedia.org/w/index.php?title=Bencode&oldid=944535013