From: Phillip Gawlowski <cmdjackryan@...>
Date: 2007-03-25T00:27:19+09:00
Subject: Re: scope and RAII

jeff_alexander_44@yahoo.com wrote:

> Does ruby make a special effort to release a variable when it goes out
> of scope?  The canonical example is
> 
> File.open("foo.txt") { |f|
>     print f.read
> }
> # internal file handle released here
> 
> Is this behavior a general rule, or just a special case for
> File.open()?  And is it released immediately or upon the
> next GC pass?

The file handle should be released ASAP if you use:

file = File.open("foo", "r")	#opens foo in read-only mode
file.readlines { |f| print f }	#prints each line
file.close			#closes the file handle.

In that case, you can use the mixins from IO via File, including, but 
not limited, to IO#close.

IMHO, it is a good idea to tell Ruby the mode it should open a file, too.[0]

Disclaimer: I'm still a Ruby nuby, and don't know anything about the 
inner workings of Ruby itself.

Bibliography:
[0] http://www.zenspider.com/Languages/Ruby/QuickRef.html#15

-- 
Phillip "CynicalRyan" Gawlowski

Rule of Open-Source Programming #20:

Open Code != Good Code