mirror of
https://github.com/20kdc/OC-KittenOS.git
synced 2024-11-09 20:18:07 +11:00
73 lines
2.1 KiB
Lua
73 lines
2.1 KiB
Lua
-- This is released into the public domain. XX
|
|
-- No warranty is provided, implied or otherwise. XX
|
|
local sector = io.write -- XX
|
|
-- XX
|
|
-- BUNDIVIDE (r5 edition) reference implementation for integration XX
|
|
-- Lines ending with XX are not included in the output. XX
|
|
-- Lines that both start and end with -- are only for use in the output, XX
|
|
-- and are thus not executed during any sanity-check procedure. XX
|
|
-- XX
|
|
Cp,Ct,Cc,Cw="","","",("\x00"):rep(65536)
|
|
-- High-level breakdown: XX
|
|
-- CP is unescaper & TAR-sector-breakup. XX
|
|
-- It'll only begin to input if at least 3 bytes are available, XX
|
|
-- so you'll want to throw in 2 extra zeroes at the end of stream as done here. XX
|
|
-- It uses Ct (input buffer) and Cp (output buffer). XX
|
|
-- Ignore its second argument, as that's a lie, it's just there for a local. XX
|
|
-- CD is the actual decompressor. It has the same quirk as CP, wanting two more bytes. XX
|
|
-- It stores to Cc (compressed), and Cw (window). XX
|
|
-- It uses Ca as the "first null" activation flag. XX
|
|
-- It outputs that which goes to the window to CP also. XX
|
|
-- And it also uses a fake local. XX
|
|
CP = function (d, b)
|
|
Ct = Ct .. d
|
|
while #Ct > 2 do
|
|
b = Ct:byte()
|
|
Ct = Ct:sub(2)
|
|
if b == 127 then
|
|
b = Ct:byte()
|
|
Ct = Ct:sub(2)
|
|
if b == 127 then
|
|
b = Ct:byte() + 254
|
|
if b > 255 then
|
|
b = b - 256
|
|
end
|
|
Ct = Ct:sub(2)
|
|
else
|
|
b = b + 127
|
|
end
|
|
end
|
|
Cp = Cp .. string.char(b)
|
|
if #Cp == 512 then
|
|
sector(Cp)
|
|
Cp = ""
|
|
end
|
|
end
|
|
end
|
|
-- XX
|
|
CD = function (d, b, p)
|
|
Cc = Cc .. d
|
|
while #Cc > 2 do
|
|
b = Cc:byte()
|
|
if not Ca then
|
|
Ca, b, Cc = b < 1, "", Cc:sub(2)
|
|
elseif b < 128 then
|
|
b, Cc = Cc:sub(1, 1), Cc:sub(2)
|
|
else
|
|
p = Cc:byte(2) * 256 + Cc:byte(3) + 1
|
|
b, Cc = Cw:sub(p, p + b - 125), Cc:sub(4)
|
|
end
|
|
CP(b)
|
|
Cw = (Cw .. b):sub(-65536)
|
|
end
|
|
end
|
|
-- XX
|
|
CD(io.read("*a")) -- XX
|
|
--D.remove("init-bdivide.lua")--
|
|
--D.rename("init.lua","init-bdivide.lua")--
|
|
--local Ch=D.open("init-bdivide.lua","rb")--
|
|
--dieCB=function()D.close(Ch)D.remove("init-bdivide.lua")end--
|
|
--while true do local t=D.read(Ch, 64)if not t then break end CD(t)end--
|
|
-- XX
|
|
CD("\x00\x00")CP("\x00\x00")
|