LuaWAK is a single-file LuaJIT library that makes use of FFI to read, alter and write files in the Noita WizardPak (.wak) format, such as the game's assets archive data.wak.

local wak = require("wak") -- load the library
                           -- you can also use something like:
			   -- local wak = loadfile("mods/my_mod/files/wak.lua")()

local ar = wak.open("data/data.wak") -- open the .wak file

local file = ar:open("data/enemies_gfx/iceskull.png") -- open any file within the data.wak

file:write("iceskull.png") -- write the data into a file on-disk

local wak = require("wak")
local ar = wak.open("data/data.wak")
local materials_file = ar:open("data/materials.xml")

local materials_xml = materials_file:read() -- read the contents of the file into a string

print(materials_xml)

for file in ar:files() -- iterate all the files in the archive
    print(file)
end

local wak = require("wak")
local ar = wak.open("data/data.wak")

ar:set("data/materials.xml", "<Materials> </Materials>") -- set the contents of the file

ar:add("data/my_file.txt", "Hello!") -- add a new file

local my_file = ar:open("data/my_file.txt") 
print(my_file:read()) -- added files work like normal

ar:write("data/data.wak.new") -- write the modified archive

local wak = require("wak")
local ar = wak.new()

ar:add("1.txt", "One") -- add a file
ar:add("2.txt", "Two") -- add another file
ar:set("3.txt", "Three") -- :set does the same thing

ar:write("my.wak") -- write the new archive to disk

• global table wak

  • function open(path : string, lenient : boolean?) : wak_archive

    opens a .wak file and returns its representation as a wak_archive object
    if the lenient optional argument is passed as true the function will return nil if the file can't be opened, otherwise an error will be raised

  • function new() : wak_archive

    creates a new in-memory wak archive

• type wak_archive

  • field path

    contains the path that the archive has been loaded from
    initialized with "(memory)" for archives created with wak.new()

  • function preload_all()

    preloads metadata about all files
    luawak conserves memory and maintains speed by avoiding reading the entire file - instead, chunks are loaded as they are needed, e.g. to grab a particular file; this function forces the entire file to be loaded (but note that the file stream will still be owned by the object)

  • function open(path : string) : wak_file

    opens a file within the archive and returns it

  • function extract(path : string, out_path : string)

    extracts a file from the archive into an on-disk file
    will do nothing if path doesn't exist in the archive

  • function add(path : string, content : string) : wak_file

    adds a file named path with content as the data to the archive
    returns the wak_file object that was added
    will raise an error if the file exists will cause the entire archive to be loaded into memory

  • function set(path : string, content : string) : wak_file

    adds or changes a file named path in the archive, setting its content to content
    returns the wak_file object that was added
    will work for both existing files and new files
    will not load any more data from the archive than is already in memory

  • function import(path : string, imp_path : string) : wak_file

    adds or changes a file named path in the archive, setting its content to the data in a file specified by imp_path
    same behavior as :set

  • function remove(path : string)

    removes the file at path from the archive
    will do nothing if the file doesn't exist

  • function count_files() : number

    returns a count of all files in the archive, including files added by :add/:set/:import
    will cause the entire archive to be loaded into memory

  • function files() : iterator<wak_file>

    the :files function acts as an iterator, providing a wak_file object each loop
    it's used similar to ipairs and pairs: for file in archive:files()

  • function force_rebuild_on_write()

    by default, if no changes are made to an archive, :write is essentially just a copy of the file
    if changes are made, the function automatically switches to rebuilding the entire archive from scratch
    if this function is called once before any calls to :write, luawak will drop the above behavior and always choose to rebuild the archive

  • function write(out_path : string)

    writes the whole archive to a file on disk
    if the archive has been modified or :force_rebuild_on_write has been called before, the archive will be rebuilt from scratch at the provided file path
    this function will reject writing to an out_path that is the same as the path the archive had been loaded from due to luawak's streaming behavior - see :write_and_dispose below

  • function write_and_dispose(out_path : string)

    same behavior as :write
    however, after this function quits, the object is disposed and unusable (see :dispose)
    this method can write to the same out_path as the path that the archive was initially loaded from

  • function dispose()

    closes the underlying file stream and disposes of the archive's resources, rendering it unusable
    note: dispose() is called automatically when the archive object is garbage collected; calling it more than one time is perfectly valid and has no effect
    calling any functions on a disposed object will raise errors

• type wak_file

  • field length

    length of the file in bytes

  • field path

    path to the file within the .wak archive

  • function read() : string

    returns the data of the file as a string

  • function write(out_path) nil

    writes the wak file into an on-disk file at the path specified by out_path

LuaWAK is licensed under the MIT license. See LICENSE in this repository.