From: Guillaume Marcais <guslist@...>
Date: 2006-09-17T00:39:13+09:00
Subject: Re: IO#dup

Le 16 sept. 06, � 09:51, ts a �crit :

>>>>>> "G" == Guillaume Marcais <guslist@free.fr> writes:
>
> G> How to do the same thing in Ruby? There is no IO#dup or IO#dup2. 
> Only
> G> IO#reopen.
>
> moulon% ruby -e 'p $stdin,$stdin.dup'
> #<IO:0xb7d78040>
> #<IO:0xb7d71f38>
> moulon%

Duh!

I got confused by the documentation. ri IO#dup doesn't return anything 
and I thought that IO#dup would be Object#dup, i.e. it would not do a 
file descriptor dup. But it does:

[gus@genome1] 1 1 ~% ruby -e 'p $stdin.fileno,$stdin.dup.fileno'
0
3

Greping the source of Ruby for rb_cIO, I cannot find the place where 
IO#dup is defined in the IO class. I do see the function ruby_dup, but 
this is an internal function that works on int, not VALUE. I am 
confused...

Could the ri documentation be fixed? I would summit a patch if I knew 
where to insert the documentation...

Thanks Guy.

Guillaume.

> -- 
>
> Guy Decoux
>
>