Erlang NBT (Named Binary Tag) file library

This library is for reading and writing the NBT file format which is used by the sandbox game Minecraft.

File format is described here (Named Binary Tag). It is the most up to date version of the specification (includes type 11 = IntArray).

Motivation

I like Erlang. I want to learn more (especially Erlang's binary processing and bit syntax). Erlang is not only made for concurrency but also for binary data handling.

After reading the specs I thought, NBT is a very cool format to store structured data. Although it has some limitations, it covers most used types. And so it can save the data in a more compact way than term_to_binary/1,2 can do.

(Yes, I have already seen the other implementation in Erlang. I don't care; it's just for fun and learning.)

Usage

Compile nbt.erl in src/. (I will rebar'fy this project soon.)

% Load a gzipped NBT file:
Data = nbt:read_gzip_file("path/to/file.nbt").
%% this is the combination of "nbt:open_gzip_file/1" and "nbt:parse_data/1"
%% other opener/reader: open_plain_file/1, read_plain_file/1
%% read_gzip_file/1 can also be used in shortened form read_file/1, because
%% gzipped nbt files are most common type so far

% Write the erlang nbt tuple to disk
% I use *.nrl as extension ("NBT in Erlang")
nbt:unconsult("path/to/file.nrl", Data).

% And read the nbt tuple again from .nrl:
ConsultedData = nbt:consult("path/to/file.nrl").

Status

• parse a nbt file (plain or gzipped) -> {nbt, …NBT DATA…}
• save the nbt tuple to a file (nbt:unconsult/2, for debugging)
• read the nbt tuple from file (nbt:consult/2, for debugging)

TODO

• refactoring!!!
• writing a nbt file from erlang tuple
• parser for MC region files in Anvil file format (*.mca)
• did I mention refactoring?