Bin To Cee

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bin2c is a utility that converts a binary file to a C char string that can be embedded in a C program via #include.

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


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Last edited November 28, 2012 4:07 am GMT (diff)