This page hosts a formal specification of .pak file format of Quake game engine using Kaitai Struct. This specification can be automatically translated into a variety of programming languages to get a parsing library.
All parsing code for Ruby generated by Kaitai Struct depends on the Ruby runtime library. You have to install it before you can parse data.
The Ruby runtime library can be installed from RubyGems:
gem install kaitai-structParse a local file and get structure in memory:
data = QuakePak.from_file("path/to/local/file.pak")
Or parse structure from a string of bytes:
bytes = "\x00\x01\x02..."
data = QuakePak.new(Kaitai::Struct::Stream.new(bytes))
After that, one can get various attributes from the structure by invoking getter methods like:
data.magic # => get magic
# This is a generated file! Please edit source .ksy file and use kaitai-struct-compiler to rebuild
require 'kaitai/struct/struct'
unless Gem::Version.new(Kaitai::Struct::VERSION) >= Gem::Version.new('0.9')
raise "Incompatible Kaitai Struct Ruby API: 0.9 or later is required, but you have #{Kaitai::Struct::VERSION}"
end
##
# @see https://quakewiki.org/wiki/.pak#Format_specification Source
class QuakePak < Kaitai::Struct::Struct
def initialize(_io, _parent = nil, _root = self)
super(_io, _parent, _root)
_read
end
def _read
@magic = @_io.read_bytes(4)
raise Kaitai::Struct::ValidationNotEqualError.new([80, 65, 67, 75].pack('C*'), magic, _io, "/seq/0") if not magic == [80, 65, 67, 75].pack('C*')
@ofs_index = @_io.read_u4le
@len_index = @_io.read_u4le
self
end
class IndexStruct < Kaitai::Struct::Struct
def initialize(_io, _parent = nil, _root = self)
super(_io, _parent, _root)
_read
end
def _read
@entries = []
i = 0
while not @_io.eof?
@entries << IndexEntry.new(@_io, self, @_root)
i += 1
end
self
end
attr_reader :entries
end
class IndexEntry < Kaitai::Struct::Struct
def initialize(_io, _parent = nil, _root = self)
super(_io, _parent, _root)
_read
end
def _read
@name = (Kaitai::Struct::Stream::bytes_terminate(Kaitai::Struct::Stream::bytes_strip_right(@_io.read_bytes(56), 0), 0, false)).force_encoding("UTF-8")
@ofs = @_io.read_u4le
@size = @_io.read_u4le
self
end
def body
return @body unless @body.nil?
io = _root._io
_pos = io.pos
io.seek(ofs)
@body = io.read_bytes(size)
io.seek(_pos)
@body
end
attr_reader :name
attr_reader :ofs
attr_reader :size
end
def index
return @index unless @index.nil?
_pos = @_io.pos
@_io.seek(ofs_index)
@_raw_index = @_io.read_bytes(len_index)
_io__raw_index = Kaitai::Struct::Stream.new(@_raw_index)
@index = IndexStruct.new(_io__raw_index, self, @_root)
@_io.seek(_pos)
@index
end
attr_reader :magic
attr_reader :ofs_index
attr_reader :len_index
attr_reader :_raw_index
end