vpkreader.lua

require'vstruct'

local metatable  = {
	__index = {
		read = function(self,n)
			if not n then
				n = 1
			end
			self.pos = self.pos+n
			if self.pos-1>#self.str then return false end
			return self.str:sub(self.pos-n,self.pos-1)
		end,
		seek = function(self,n)
			self.pos = n
		end,
		
		int4 = function(self)
			return vstruct.readvals('u4',self:read(4))
		end,
		
		int2 = function(self)
			return vstruct.readvals('u2',self:read(2))
		end,
		
		sz = function(s)
			local out = {}
			while true do
				local cur = s:read(1)
				if not cur or cur =='\0' then break end
				out[#out+1] = vstruct.readvals('s1',cur)
			end
			if #out==0 then return false end
			return table.concat(out,'')
		end,
		
	},
	
	__tostring = function(self)
		return self.str
	end,
	
	__add = function(self,n)
		return self:read(n)
	end,
	__sub = function(self,n)
		return self:read(-n)
	end,
	
}
local function createString(str)
	local s = {
		str=str,
		pos = 1,
	}
	debug.setmetatable(s,metatable)
	return s
end


local file = createString(file.Read('garrysmod_dir.vpk','GAME'))
	
local signature = GLib.String.DumpHex(file:read(4))
local version = file:int4()
local dirlength = file:int4()

local unknown1 = file:int4()
local unknown2 = file:int4()
local unknown3 = file:int4()
local unknown4 = file:int4()

print(signature)
print(version)
print(dirlength)

while true do
	
	local ext = file:sz()
	if not ext then break end
	
	while true do
		local folder = file:sz()
		if not folder then break end
		
		while true do
			local filename = file:sz()
			if not filename then break end
			
			local path = string.format('%s/%s.%s',folder,filename,ext)
			print(path)
			
			local CRC = file:int4()
			local preload_bytes = file:int2()
			
			local archive_index = file:int2()
			if archive_index == '\x7fff' then
				ErrorNoHalt('EMBED')
			end
			
			
			local offset = file:int4()
			local length = file:int4()
			
			file:int2()
			
			if preload_bytes and preload_bytes!=0 then
				file:read(preload_bytes)
			end
			
		end
		
	end
	
end