From: Gabriel Dragffy <gabe@...>
Date: 2007-08-23T20:47:21+09:00
Subject: Re: Renaming Files


On 23 Aug 2007, at 12:27, Peter Hickman wrote:

> The problem here is the ! on the gsub. This is changing the  
> contents of f *before* it gets passed to the function:
>
> def show(a, b)
>    puts "[#{a}] [#{b}]"
> end
>
> x = "Here is a string"
>
> show(x, x.gsub!(/\s/,'_'))
>
> results in
>
> [Here_is_a_string] [Here_is_a_string]
>
> But change the gsub! to a plain gsub and you get
>
> [Here is a string] [Here_is_a_string]
>
> because a plain gsub returns a copy of the modified string without  
> modifying the original.
>
> Only use the ! versions when you are absolutely sure you need to.
>
>

Thank you so much for these replies (Peter & Stefano). That makes  
perfect sense. As soon as you pointed out gsub! was doing what is was  
supposed to :)
Thanks. I just renamed a directory of about 30 files in 0.5 seconds  
with that one.

Just another quicky, if I wanna rename all the files in the directory  
is what I did OK, using:
	next if f=="." or f==".."

I just feel there must a better way?

Best regards Gabriel