Bin To Cee

wiki

Description

bin2c can be useful, for example, to embed Lua bytecodes into a C binary, but it has more general uses too (e.g. embedding image files).

Source

The Lua distribution no longer contains bin2c.c, but you can find it in earlier versions (e.g. Lua 5.0 [1]) as well as in [LuaBinaries].

bin2c can also be written in Lua. This following Lua version is meant to be a complete and improved replacement. This program and its C output both require Lua 5.1. You can download [bin2c.lua], or just read it below.

Lua reimplementation of bin2c

local description = [=[

Usage: lua bin2c.lua [+]filename [status]



Write a C source file to standard output.  When this C source file is

included in another C source file, it has the effect of loading and

running the specified file at that point in the program.



The file named by 'filename' contains either Lua byte code or Lua source.

Its contents are used to generate the C output.  If + is used, then the

contents of 'filename' are first compiled before being used to generate

the C output.  If given, 'status' names a C variable used to store the

return value of either luaL_loadbuffer() or lua_pcall().  Otherwise,

the return values of these functions will be unavailable.



This program is (overly) careful to generate output identical to the

output generated by bin2c5.1 from LuaBinaries.



http://lua-users.org/wiki/BinTwoCee



Original author: Mark Edgar

Licensed under the same terms as Lua (MIT license).

]=]



if not arg or not arg[1] then

  io.stderr:write(description)

  return

end



local compile, filename = arg[1]:match"^(+?)(.*)"

local status = arg[2]



local content = compile=="+"

  and string.dump(assert(loadfile(filename)))

  or assert(io.open(filename,"rb")):read"*a"



local function boilerplate(fmt)

  return string.format(fmt,

    status and "("..status.."=" or "",

    filename,

    status and ")" or "",

    status and status.."=" or "",

    filename)

end



local dump do

  local numtab={}; for i=0,255 do numtab[string.char(i)]=("%3d,"):format(i) end

  function dump(str)

    return (str:gsub(".", numtab):gsub(("."):rep(80), "%0\n"))

  end

end



io.write(boilerplate[=[

/* code automatically generated by bin2c -- DO NOT EDIT */

{

/* #include'ing this file in a C program is equivalent to calling

  if (%sluaL_loadfile(L,%q)%s==0) %slua_pcall(L, 0, 0, 0); 

*/

/* %s */

static const unsigned char B1[]={

]=], dump(content), boilerplate[=[



};



 if (%sluaL_loadbuffer(L,(const char*)B1,sizeof(B1),%q)%s==0) %slua_pcall(L, 0, 0, 0);

}

]=])

See Also

• [Precompiler and Preloader] - These two utilities included in the LOOP package extend the bin2c concept to specially handle modules that follow the Lua 5.1 package model. The Precompiler utility compiles (if not already compiled) one or more Lua modules into a pair of C source and header files containing the bytecodes and functions to load those byte codes. Those function have signatures following the Lua 5.1 package model (e.g. int luaopen_loop_base(lua_State*)). The Preloader utility builds another pair of C source and header files containing a function to preload those modules (i.e. package.preload table) into Lua states.
• LuaList:2008-06/msg00361.html - simple module preloader compiler script
• LuaList:2008-08/msg00092.html - Lhf's version of luac supporting require.
• LuaToCee - convert Lua source to C API calls
• srlua[2] - a tool for building self-running Lua programs
• LuaList:2008-11/msg00449.html - "Embedding Lua bytecode in C binary" discussion
• [Lua2C.lua] - embeds Lua scripts in C headers. Able to strip comments and whitespace from source code and to obfuscate (XOR) the embedded bytes so as to render them undecipherable (binary garbage).
• [Squish] (5.1) - a tool to pack individual scripts and their modules into a single script. Supports a range of filters.