From: Zach Dennis <zdennis@...>
Date: 2004-12-28T22:48:04+09:00
Subject: Re: verifying a network connection

Thomas Metz wrote:
> Hi,
> 
> is there a way in Ruby to find out, whether my computer has built up a
> network connection or not?
> 
> I'm using Windows2000.
> 
> Thank you for helping a Ruby-newbie.
> 

Hi Thomas,

A quick and easy solution is the following, which work on a windows machine.

ip_str = `ipconfig`
ip_str =~ /IP Address[^\d]*((\d+\.){3}\d+)/
ip_addr = $1

Note that those are backticks around "ipconfig". I haven't tested this 
for a machine that doesn't have a ip address, so I'll leave that up to you.

You can shorten this by just saying:

`ipconfig` =~ /IP Address[^\d]*((\d+\.){3}\d+)/
ip_addr = $1

Here's a quick explanation (I dont know if you're new to ruby or to 
programming, so bare with me). The parts of the regex are in quotes:

  - `ipconfig` executes a shell command, aka ipconfig!
  - /IP Address[^\d]*((\d+\.){3}\d+)/ is a regular expression meaning:
	- Find the word IP Address, "IP Address"
	- which is followed by a non-digit as many times as possible "[^\d]*"
	- until we find one or more digits "\d+"
	- (which is followed by a period) at least 3 times "\.{3}"
	- and is followed by one or more digits "\d+"
	- The parenthesis's are used to group the match

HTH,

Zach