I wrote this like two months ago

lzsip/OpenOS/usr/bin/lzsip.lua

@@ -0,0 +1,89 @@
+local lz = require "lzss"
+local shell = pcall(require,shell)
+
+local tA, tO = {}, {}
+if shell then
+ tA, tO = shell.parse(...)
+else
+ tA, tO = {...}, {}
+end
+tO.bsize = tO.bsize or 16384
+
+local function cint(n,l)
+ local t={}
+ for i = 0, 7 do
+  t[i+1] = (n >> (i * 8)) & 0xFF
+ end
+ return string.reverse(string.char(table.unpack(t)):sub(1,l))
+end
+local function toint(s)
+ s=s or ""
+ local n = 0
+ local i = 1
+ while true do
+  local p = s:sub(i,i)
+  if p == "" then break end
+  local b = string.byte(p)
+  n = n << 8
+  n = n | b
+  i=i+1
+ end
+ return n
+end
+
+local function cfile(fn)
+ local fi = io.open(fn,"rb")
+ if not fi then return false end
+ local fo = io.open(fn..".lss","wb")
+ if not fo then fi:close() return false end
+ fo:write("lz16") -- write header
+ while true do
+  local rblock = fi:read(tO.bsize)
+  if rblock == "" or not rblock then break end
+  local cblock = lz.compress(rblock)
+  fo:write(cint(cblock:len(),2)..cblock)
+ end
+ fi:close()
+ fo:close()
+ return true
+end
+local function xfile(fn)
+ local fi = io.open(fn,"rb")
+ if not fi then return false, "unable to open input file" end
+ if fi:read(4) ~= "lz16" and not tO.f then
+  return false, "not an lz16 archive"
+ end
+ local fo = io.open(fn:sub(1,-5),"wb")
+ if not fo then fi:close() return false, "unable to open output file" end
+ while true do
+  local len = toint(fi:read(2) or "\0\0")
+  if len < 1 then
+   break
+  end
+  fo:write(lz.decompress(fi:read(len)))
+ end
+ fi:close()
+ fo:close()
+ return true
+end
+
+if tO.x then -- extract
+ for k,v in pairs(tA) do
+  io.write(v.."...")
+  local s,r = xfile(v)
+  if s then
+   print(" done")
+  else
+   print(" failed: "..r)
+  end
+ end
+else -- create
+ for k,v in pairs(tA) do
+  io.write(v.."...")
+  if cfile(v) then
+   print(" done.")
+  else
+   print(" failed.")
+  end
+ end
+end

lzsip/OpenOS/usr/lib/lzss.lua

@@ -0,0 +1,123 @@
+--[[----------------------------------------------------------------------------
+
+	LZSS - encoder / decoder
+
+	This is free and unencumbered software released into the public domain.
+
+	Anyone is free to copy, modify, publish, use, compile, sell, or
+	distribute this software, either in source code form or as a compiled
+	binary, for any purpose, commercial or non-commercial, and by any
+	means.
+
+	In jurisdictions that recognize copyright laws, the author or authors
+	of this software dedicate any and all copyright interest in the
+	software to the public domain. We make this dedication for the benefit
+	of the public at large and to the detriment of our heirs and
+	successors. We intend this dedication to be an overt act of
+	relinquishment in perpetuity of all present and future rights to this
+	software under copyright law.
+
+	THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+	EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+	MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+	IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
+	OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+	ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+	OTHER DEALINGS IN THE SOFTWARE.
+
+	For more information, please refer to <http://unlicense.org/>
+
+--]]----------------------------------------------------------------------------
+--------------------------------------------------------------------------------
+local M = {}
+local string, table = string, table
+
+--------------------------------------------------------------------------------
+local POS_BITS = 12
+local LEN_BITS = 16 - POS_BITS
+local POS_SIZE = 1 << POS_BITS
+local LEN_SIZE = 1 << LEN_BITS
+local LEN_MIN = 3
+
+--------------------------------------------------------------------------------
+function M.compress(input)
+	local offset, output = 1, {}
+	local window = ''
+
+	local function search()
+		for i = LEN_SIZE + LEN_MIN - 1, LEN_MIN, -1 do
+			local str = string.sub(input, offset, offset + i - 1)
+			local pos = string.find(window, str, 1, true)
+			if pos then
+				return pos, str
+			end
+		end
+	end
+
+	while offset <= #input do
+		local flags, buffer = 0, {}
+
+		for i = 0, 7 do
+			if offset <= #input then
+				local pos, str = search()
+				if pos and #str >= LEN_MIN then
+					local tmp = ((pos - 1) << LEN_BITS) | (#str - LEN_MIN)
+					buffer[#buffer + 1] = string.pack('>I2', tmp)
+				else
+					flags = flags | (1 << i)
+					str = string.sub(input, offset, offset)
+					buffer[#buffer + 1] = str
+				end
+				window = string.sub(window .. str, -POS_SIZE)
+				offset = offset + #str
+			else
+				break
+			end
+		end
+
+		if #buffer > 0 then
+			output[#output + 1] = string.char(flags)
+			output[#output + 1] = table.concat(buffer)
+		end
+	end
+
+	return table.concat(output)
+end
+
+--------------------------------------------------------------------------------
+function M.decompress(input)
+	local offset, output = 1, {}
+	local window = ''
+
+	while offset <= #input do
+		local flags = string.byte(input, offset)
+		offset = offset + 1
+
+		for i = 1, 8 do
+			local str = nil
+			if (flags & 1) ~= 0 then
+				if offset <= #input then
+					str = string.sub(input, offset, offset)
+					offset = offset + 1
+				end
+			else
+				if offset + 1 <= #input then
+					local tmp = string.unpack('>I2', input, offset)
+					offset = offset + 2
+					local pos = (tmp >> LEN_BITS) + 1
+					local len = (tmp & (LEN_SIZE - 1)) + LEN_MIN
+					str = string.sub(window, pos, pos + len - 1)
+				end
+			end
+			flags = flags >> 1
+			if str then
+				output[#output + 1] = str
+				window = string.sub(window .. str, -POS_SIZE)
+			end
+		end
+	end
+
+	return table.concat(output)
+end
+
+return M