From: "David A. Black" <dblack@...>
Date: 2005-07-18T21:14:51+09:00
Subject: Re: Reading total lines of file then displaying in reverse?

Hi --

On Mon, 18 Jul 2005, Tristan Knowles wrote:

>
> --- "David A. Black" <dblack@wobblini.net> wrote:
>>> File.readlines("my.log").reverse.each{|l| puts l}
>>
>> I believe that's identical to:
>>
>>    puts File.readlines("my.log").reverse
>
>
> For my case, it now looks like this:
>
> lines = IO.readlines("my.log").reverse.each_with_index
> do |line, index|
>
>
> I'm trying to use .length somewhere now to count the
> number of lines.

One possibility:

   class Array
     def map_with_index
       res = []
       each_with_index {|e,i| res << yield(e, i) }
       res
     end
   end

   puts File.readlines("my.log").map_with_index {|*a| a }.reverse

(Not optimally efficient, I think, but anyway.)


David

-- 
David A. Black
dblack@wobblini.net