From: Brian Candler <B.Candler@...>
Date: 2003-03-16T23:51:09+09:00
Subject: Re: Can't think

On Sun, Mar 16, 2003 at 07:33:59PM +0900, Tim Bates wrote:
> I want to do this:
>   mystring.split("\n").delete_if{ |s| s =~ /^\s*$/ }.join("\n")
> using gsub ('cause it'd be nicer). So what I'm doing is removing those lines 
> that consist of only whitespace. I tried this:
>   mystring.gsub(/^\s*$/, "")
> This removes the whitespace, but not the newline, like the above one does. So 
> really, the question is how do I get the regexp to match the newline?

    mystring =  "This is\n    \nsome\n\n\ntext\n"
    p mystring.gsub(/^\s*\n/,"")
    >> "This is\nsome\ntext\n"

i.e. since $ means 'match before newline' you can just a match a newline
explicitly (and hence chomp it)

However $ also means 'match end of string', so in this case a final line
which consists only of spaces but with no trailing \n will not get removed.

If that's a problem you can fix it by changing \n to (\n|$), although that
gets a bit weird since ($|\n) behaves differently.

Regards,

Brian.