From: William James <w_a_x_man@...>
Date: 2007-09-23T19:00:13+09:00
Subject: Re: I am new to Ruby and I could use some expert advice as to how I can make this code run faster.

On Sep 22, 5:16 am, William James <w_a_x_...@yahoo.com> wrote:
> On Sep 20, 5:02 pm, Ruby Maniac <raych...@hotmail.com> wrote:
>
> > I am new to Ruby and I could use some expert advice as to how I can
> > make this code run faster.
>
> > def scramble(fname)
> >     f = File.new(fname, "rb")
> >     _fname = fname + ".scrambled"
> >     begin
> >         File.exist?(_fname) if File.delete(_fname)
> >     rescue
> >     end
> >     ff = File.new(_fname, "wb+")
> >     for l in f
> >         l.each_byte{|c| ff.write((c | 0x80).chr) }
> >     end
> >     f.close()
> >     ff.close()
> > end
>
> If you actually want speed, use a compiled language.
> This FreeBasic code is about 160 times as fast and
> demonstrates that using Python for any reason
> whatsoever is unjustified.
>
> Use Ruby when ease of programming is paramount;
> use something like FreeBasic or LuaJIT when speed
> is paramount.  Never submit to Python perversion.
>
> sub scramble( filename as string )
>   dim outname as string
>   dim as integer  in_handle, out_handle, i, size
>   dim bytes(1 to 4096) as byte
>
>   outname = filename & ".scrambled"
>   in_handle = freefile
>   open filename for binary access read  as in_handle
>   out_handle = freefile
>   open outname for binary access write  as out_handle
>   while not eof( in_handle )
>     size = seek( in_handle )
>     get #in_handle, , bytes()
>     size = seek( in_handle ) - size
>     for i = 1 to size
>       bytes(i) = bytes(i) or &h80
>     next
>     put #out_handle, , bytes(1), size
>   wend
>   close
> end sub

If that prolixity bothered you, look at a
version in the J programming language.

read =: 1!:1
write =: 1!:2
scramble =: verb define
((128 (23 b.) a. i. read <y) { a. ) write <y,'.scrambled'
)

scramble 'myfile'