From: Matthew Desmarais <desmarm@...>
Date: 2006-04-06T08:45:14+09:00
Subject: Re: Copying $1.. A loop with two regular expressions

Hi there,

Oky wrote:
> Hi, sorry if this is a stupid question.. i've only been programming ruby 
> for about six hours.
>
> I'm trying to white a loop to parse through a webpage and get all the 
> links to other pages. This loop depends on a regular expression to find 
> all the <a href tags.. but inside the loop there is another regular 
> expression which looks to see if the link is relative or static. The 
> problem is the inner regular expression changes the $1 variable so the 
> loop just fails on the first iteration. I've tried making a copy of the 
> $1 variable but the result just ends up containing nil.
>
> Any help you could offer would be gratefully appreciated
>
> Hears my code so far:
>
>     	loop do
>     	 	url = $1
>     		puts $1    #A url
>     		puts $url  #Always nil ?
>   
Here's _a_ problem for you to start with.  You've assigned the value of 
1 to the local variable url.  When you puts $url, you are examining and 
printing the global variable $url.  Since you haven't assigned anything 
to $url yet, it is nil.

In Ruby an unadorned name like "url" is either a local variable or 
method call.  Putting a "$" on the front of something tells Ruby that 
you want to refer to a global.

So try changing the "$url" to "url" and see what happens.

I hope it's something good.

Matthew