Re: binary string modified

[nobody <nobody+lua-list@...>]

On 2016-08-20 23:09, Satoru Kawahara wrote:
> Hello,
> 
> I tried to copy luac.out into a script file as string and run the native
> code string with `load()`.

Did you use a literal/long string ([[...]])?  It seems to normalize all
line endings (0d0a / \r\n --> 0a / \n), thereby breaking it.

That is,

  ~$ { echo "io.stdout:write [[" ; cat luac.out ; echo "]]" ; } > a.lua
  ~$ lua a.lua > b.lua
  ~$ diff luac.out b.lua
  Binary files luac.out and c.lua differ

But you can escape special characters and use a normal string:

  f = io.open( "luac.out", "rb" )
  code = f:read"a":gsub( "[%G'\\]", function( c )
    return ("\\x%02x"):format( c:byte() )
  end )
  io.stdout:write( "print( pcall( assert( load '", code, "' ) ) )\n" )

Or, escaping just the minimum (and then you hope your editor doesn't
change anything and breaks it):

  subst = {
    ["\r"] = "\\r", ["\n"] = "\\n", ["\\"] = "\\\\", ["'"] = "\\'",
  }
  f = io.open( "luac.out", "rb" )
  code = f:read"a":gsub( ".", subst )
  io.stdout:write( "print( pcall( assert( load '", code, "' ) ) )\n" )