From: Jeremy McAnally <jeremymcanally@...>
Date: 2008-02-18T13:32:03+09:00
Subject: Re: Help with Writing Replacement Text to Files

Try this:

File.open("config.txt", "rw") do |f|
  text = f.read
  text.gsub!(/\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}/, "000.000.000.000")
  f.rewind
  f.write(text)
end

Using the block form like that will automagically close the file when
it ends. :)

--Jeremy

On Feb 17, 2008 11:00 PM, Thomas Pierce <ruby@upgradeyourmind.com> wrote:
> Hello!
>
> I'm new to ruby and been reading this very active list for about a
> couple of week.
>
> I have a project at work where I need to write a simple script to
> scrub IP addresses from configuration files for classified networks we
> work in sometimes. The goal is to cleanse configuration files
> sometimes required for support of any specific network addressing
> information. Here is what I've come up with so far. While this works
> in IRB on the file object I create, I cannot figure out how to write
> the changes back in place to the actual file itself back on the regex
> I'm using:
>
>   config_file = File.open("config.txt")
>          config_txt = config_file.read
>          config_txt.gsub!(/\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}/,
> "000.000.000.000")
>
> I do understand that the default action here is read-only. How to do I
> parse with the regex on the current file and replace matching strings
> without either appending to the file, overwriting the file, or
> creating a new file?
>
> Thanks!
>
> ~Thomas
>
>



-- 
http://jeremymcanally.com/
http://entp.com

Read my books:
Ruby in Practice (http://manning.com/mcanally/)
My free Ruby e-book (http://humblelittlerubybook.com/)

Or, my blogs:
http://mrneighborly.com
http://rubyinpractice.com