From: Ben Nagy <ben@...>
Date: 2006-10-23T22:03:47+09:00
Subject: Re: Binary file modification

> -----Original Message-----
> From: list-bounce@example.com 
> [mailto:list-bounce@example.com] On Behalf Of Rob Lee
> Sent: Monday, October 23, 2006 6:06 PM
> To: ruby-talk ML
> Subject: Re: Binary file modification
> 
> Ben Nagy wrote:
[...]
> > num=1024
> > num.to_s(16)[0..2].instance_eval {(self.reverse + '0' * (6 -
> > self.length)).reverse}.scan(/../).inject('') {|s,byte| s << 
> > byte.to_i(16)}
> > 
> 
> I'm intrigued by this, I can see you are repacking the int value into 
> three bytes but I'm still unclear as to how you would then 
> add this to 
> the file.

It's already packed. The return value of the long expression will be a 3
byte string which you can insert as you like (print it to the IO handle, <<
it to another string etc etc). The accumulator in the inject method is a
string {|str,byte| ... might have been more readable, sorry.

ben