From: Brian Candler <B.Candler@...>
Date: 2005-07-19T17:48:34+09:00
Subject: Re: Reading total lines of file then displaying in reverse?

On Mon, Jul 18, 2005 at 09:06:26PM +0900, Tristan Knowles wrote:
> 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.

lines.size will give you the number of lines. Are you trying to do something
like this?

    lines = File.readlines("my.log")

    lines.reverse.each_with_index do |line, index|
      index = lines.size - index
      printf "%5d %s", index, line
    end

Or:

    c = lines.size
    lines.reverse_each do |line|
      printf "%5d %s", c, line
      c -= 1
    end

Or the fancy way, if you want to iterate using each_with_index but not
create an intermediate reversed copy of the array:

    require 'enumerator'
    lines.to_enum(:reverse_each).each_with_index do |line, index|
      index = lines.size - index
      printf "%5d %s", index, line
    end

Regards,

Brian.