From: Ken Bloom <kbloom@...>
Date: 2008-10-30T10:39:15+09:00
Subject: Re: Question concerning ruby file access

On Thu, 30 Oct 2008 00:14:57 +0000, Stefan Salewski wrote:

> Question concerning ruby file access from a novice:
> 
> I have seen following code fragment from
> 
> http://www.rubycentral.com/pickaxe/tut_io.html
> 
> File.open("testfile", "r") do |aFile| # ... process the file
> end
> 
> Advantage of this notation is that file is automatically closed when do
> loop terminates -- maybe by an exception with Process.exit.
> 
> But how do I test in this notation that the file with name "testfile"
> really exits (and opening was successful). In an multi-tasking
> environment another process may delete the file just before this
> statement is executed.
> 
> Or in other words: I want to print a text like "File with filename
> "testfile" does not exist" when opening failed.
> 
> Best regards
> 
> Stefan Salewski

begin
  File.open("testfile") do |aFile|
    ...
  end
rescue IOError => e
  #handle error
end



-- 
Chanoch (Ken) Bloom. PhD candidate. Linguistic Cognition Laboratory.
Department of Computer Science. Illinois Institute of Technology.
http://www.iit.edu/~kbloom1/