From 9e7d778e211148788b01a375505e80ebbd3b8da2 Mon Sep 17 00:00:00 2001
From: XeonSquared <redtailedairways@gmail.com>
Date: Fri, 6 Mar 2020 22:10:16 +1100
Subject: [PATCH] added an mtar utility for OpenOS

---
 mtar/OpenOS/usr/bin/mtar.lua | 126 +++++++++++++++++++++++++++++++++++
 mtar/OpenOS/usr/man/mtar     |  30 +++++++++
 mtar/libmtar.lua             |  25 ++++---
 3 files changed, 170 insertions(+), 11 deletions(-)
 create mode 100644 mtar/OpenOS/usr/bin/mtar.lua
 create mode 100644 mtar/OpenOS/usr/man/mtar

diff --git a/mtar/OpenOS/usr/bin/mtar.lua b/mtar/OpenOS/usr/bin/mtar.lua
new file mode 100644
index 0000000..791da33
--- /dev/null
+++ b/mtar/OpenOS/usr/bin/mtar.lua
@@ -0,0 +1,126 @@
+local shell = require "shell"
+local mtar = require "libmtar"
+
+local args, opts = shell.parse(...)
+
+local w, lz16 = pcall(require, "liblz16")
+if not w then lz16 = nil end
+
+local function toint(s)
+ s = s or "\0"
+ local n = 0
+ local i = 1
+ for p in s:gmatch(".") do
+  n = n << 8
+  n = n | string.byte(p)
+  i=i+1
+ end
+ return n
+end
+
+local function vw(s)
+ if opts.v and s then
+  io.write(tostring(s))
+ end
+end
+
+local function vp(...)
+ for k,v in ipairs({...}) do
+  vw(tostring(v).."\n")
+ end
+end
+
+if opts.x then
+ local f
+ if opts.z then
+  f = lz16.open(args[1],"rb")
+ else
+  f = io.open(args[1],"rb")
+ end
+ if not f then error("unable to open file") end
+ local w, r = mtar.unarchive(f,args[2] or ".",opts.v)
+ f:close()
+elseif opts.t then
+ local f
+ if opts.z then
+  f = lz16.open(args[1],"rb")
+ else
+  f = io.open(args[1],"rb")
+ end
+ if not f then error("unable to open file") end
+ while true do
+  local nlen = toint(f:read(2))
+  if nlen == 0 then
+   break
+  end
+  local name = f:read(nlen)
+  local fsize = toint(f:read(2) or "\0\0")
+  f:read(fsize)
+  print(name..": "..tostring(fsize))
+ end
+ f:close()
+elseif opts.c then
+ local mode = (opts.r and "ab") or "wb"
+ local f
+ if opts.z then
+  f = lz16.open(args[1],mode)
+ else
+  f = io.open(args[1],mode)
+ end
+ if not f then error("unable to open file") end
+ table.remove(args,1)
+ local fs = require "filesystem"
+ for k,v in pairs(args) do
+  local ap = true
+  if v:sub(1,1) ~= "/" then
+   ap = false
+   v = os.getenv("PWD") .. "/" .. v
+  end
+  v=fs.canonical(v)
+  vw(v.."... ")
+  if fs.isDirectory(v) then
+   vp("directory.")
+   for file in fs.list(v) do
+    if ap then
+     args[#args+1] = v.."/"..file
+    else
+     args[#args+1] = v:sub(os.getenv("PWD"):len()+2).."/"..file
+    end
+   end
+  else
+   local fsize = fs.size(v)
+   local inputf = io.open(v,"rb")
+   if fsize and inputf then
+    local c = 0
+    if ap then
+     f:write(mtar.genHeader(v,fsize))
+    else
+     f:write(mtar.genHeader(v:sub(os.getenv("PWD"):len()+2),fsize))
+    end
+    while true do
+     local ib = inputf:read(4096)
+     if ib then
+      c=c+ib:len()
+      f:write(ib)
+     else
+      break
+     end
+    end
+    vp(c)
+   else
+    vp("failed to open.")
+   end
+  end
+ end
+ f:close()
+else
+ print([[Usage:
+ mtar -[crtxvz] <archivefile> [otherfile] [otherfile]
+Operations:
+ x: extract archive
+ c: create archive
+ t: list contents of archive
+Flags:
+ v: be verbose
+ z: use LZSS compression (requires liblz16)]])
+end
diff --git a/mtar/OpenOS/usr/man/mtar b/mtar/OpenOS/usr/man/mtar
new file mode 100644
index 0000000..1e9132b
--- /dev/null
+++ b/mtar/OpenOS/usr/man/mtar
@@ -0,0 +1,30 @@
+# mtar - Minitel Archiver
+## Usage
+
+    mtar -[crtxvz] <archivefile> [otherfile] [otherfile]
+
+## Operations
+
+ x: extract archive  
+ c: create archive  
+ t: list contents of archive
+
+## Flags
+
+ v: be verbose  
+ z: use LZSS compression (requires liblz16)]])
+
+## Examples
+
+Extract archive *example.mtar*
+
+    mtar -x example.mtar
+
+Show the files in compressed archive *example.mtar.lss*
+
+    mtar -tz example.mtar.lss
+
+Create a compressed archive *example.mtar.lss* from file *fun* and folder *junk*
+
+    mtar -cz example.mtar.lss fun junk/
+
diff --git a/mtar/libmtar.lua b/mtar/libmtar.lua
index 0b54e04..fe77f82 100644
--- a/mtar/libmtar.lua
+++ b/mtar/libmtar.lua
@@ -20,15 +20,11 @@ local function mkdir(dir)
 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)
+ for p in s:gmatch(".") do
   n = n << 8
-  n = n | b
+  n = n | string.byte(p)
   i=i+1
  end
  return n
@@ -58,17 +54,18 @@ function mtar.genHeader(fname,len) -- generate a header for file *fname* when pr
  return string.format("%s%s%s",cint(fname:len(),2),fname,cint(len,2))
 end
 
-function mtar.unarchive(stream,dest)
+function mtar.unarchive(stream,dest,verbose) -- Extract mtar archive read from *stream* to *dest*. If *verbose*, print status.
  dest = dest or "."
- mkdir(dest)
  while true do
-  local nlen = toint(stream:read(2))
+  local nlen = toint(stream:read(2) or "\0\0")
   if nlen == 0 then
    break
   end
   local name = cleanPath(stream:read(nlen))
   local fsize = toint(stream:read(2))
-  print(name,fsize)
+  if verbose then
+   io.write(name.." "..tostring(fsize).."... ")
+  end
   local dir = name:match("(.+)/.*%.?.+")
   if (dir) then
    mkdir(dir)
@@ -77,12 +74,18 @@ function mtar.unarchive(stream,dest)
   local rsize,buf = fsize, ""
   if f then
    repeat
-    buf = stream:read(math.min(rsize,1024))
+    buf = stream:read(math.min(rsize,2048))
     f:write(buf)
     rsize = rsize - buf:len()
+    if verbose then
+     io.write(tostring(rsize).." ")
+    end
    until rsize <= 1
    f:close()
   end
+  if verbose then
+   print("done.")
+  end
  end
 end