From: Heesob Park <phasis@...>
Date: 2009-03-09T10:19:47+09:00
Subject: Re: I code my first ruby script, and it got problem!

2009/3/9 Power One <arghx1@yahoo.com>:
> Once again, thank so much Park!
>
> I wonder why do I have to use ensure to have the subsequent method
> del_dir to work?
>
> After seeing you used ensure, I read on the Internet, it says that
> ensure is helping to make sure the code block within ensure will always
> be executed.
>
> Though when I do Dir.chdir("#{@dirname}"), isn't this adequate?  I saw
> that you have to use cwd = Dir.pwd, and then do Dir.chdir, and then do
> ensure again!
>
If you did Dir.chdir("#{@dirname}"), the current working directory is
"#{@dirname}".
So, the next Dir.delete("#{@dirname}") fails to work.

>
>>   def see_me
>>     if File.exist?("#{@dirname}")
>>       cwd = Dir.pwd
>>       begin
>>         Dir.chdir("#{@dirname}")
>>         puts Dir.pwd
>>       ensure
>>         Dir.chdir(cwd)
>>       end
>>     else
>>       puts "This directory #{@dirname} is not exist!"
>>     end
>>   end
>>
According to http://www.dweebd.com/ruby/temporarily-change-ruby-working-directory/
The above can be written as

   def see_me
     if File.exist?("#{@dirname}")
         Dir.chdir("#{@dirname}") do
           puts Dir.pwd
         end
     else
       puts "This directory #{@dirname} is not exist!"
     end
   end


Regards,

Park Heesob