From: Mark Probert <probertm@...>
Date: 2004-08-22T04:15:47+09:00
Subject: Re: Ruby way to update file lines

"Robert Klemme" <bob.news@gmx.net> wrote: 

> 
> Some code thoughts below
> 
> Regards
> 
>     robert
> 
> 
> # match keys
> COMMENT = lambda {|key, val| "# #{key}:#{val}"}
> DELETE  = lambda { nil }
> 
> tasks = {
>   "foo:bar" => COMMENT,
>   "foo1:bar1" => DELETE,
> }
> 
> conf = File.readlines("conf.txt")
> 
> # manipulate
> conf.map! do |line|
>   if /^([^:]+:[^:]+):(.*)$/ =~ line && (fun = tasks[$1])
>     fun.call $1, $2
>   else
>     line
>   end
> end
> 
> # remove deleted lines
> conf.compact!
> 
> File.open("conf-1.txt", "w") {|io| io.puts conf }
> 

I liked this one :-)  Thanks.

One minor correction: COMMENT and DELETE should be lower case.  Ruby 1.8 
spits and error about constants otherwise.

-mark.