From: Robert Klemme <shortcutter@...>
Date: 2010-02-11T01:13:14+09:00
Subject: Re: How to change stdin separator (perl vs ruby)

2010/2/10 Daniel Bye <ruby@slightlystrange.org>:
> On Thu, Feb 11, 2010 at 12:23:55AM +0900, Sak .. wrote:
>> I have to process very very big text files and not line per line, I have
>> to access to a group of lines seperated for a "%". Then I tryed to
>> access line per line and detect the separator for each line saving the
>> lines in a buffer, obviously it works but it's very slow (text files are
>> bigger than 1GB).
>>
>> Perl have an awesome feature that is to change the separator for
>> iterating files (by default in all languages is "\n"), this simple and
>> extremely efficent code do what I need:
>>
>> $/ = "%";
>> while ($article = <STDIN>) {
>>   #Iteration
>> }
>>
>
> If your delimiter only occurs as a delimiter, and not in the data as well:

Note that this statement is true for \n as well!

> File.open(path_to_file, 'r') do |f|
>  f.each('%') do |record|
>    # Do stuff.
>  end
> end

You can have it simpler:

File.foreach path, '%' do |record|
  # so something with record
end

Kind regards

robert

-- 
remember.guy do |as, often| as.you_can - without end
http://blog.rubybestpractices.com/