From: matt@... (matt neuburg)
Date: 2006-11-02T11:15:04+09:00
Subject: Re: Input file, change data, write to file

Paul Br <brr@blueridgeremedy.com> wrote:

> I'm a ruby newbie trying to read data from a file, make a few changes,
> and write the output to a file so it can be imported into a MySQL 
> database.
> 
> I found a partial solution on page 138 in Maik Schmidt's "Enterprise 
> Integration with Ruby" book but it lacks a means to write the output to
> a file.
> 
> How can I write the output to a file using the below code?

I think the most newbie-appealing approach to files is with

open() do |f|
end

because when the block finishes the file closes automatically. The docs
on the modes for opening files, and on the methods you need after that,
are here:

<http://www.ruby-doc.org/core/classes/IO.html>

With big data that comes in lines, where each line is to be processed
independently, you presumably want two files, reading and writing a line
at a time, so the whole operation could be structured like this:

def munge(s)
  return s.gsub(/[aeiou]/, '') # but do your own task here instead
end
open("path1", "r") do |f1|
  open("path2", "w") do |f2|
    f1.each { |line| f2.puts munge(line) }
  end
end

m.
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