From: Gregory Seidman <gsslist+ruby@...>
Date: 2007-11-20T03:08:23+09:00
Subject: Re: Read last line of a file

On Tue, Nov 20, 2007 at 12:41:46AM +0900, Robert Klemme wrote:
> 2007/11/19, Gregory Seidman <gsslist+ruby@anthropohedron.net>:
> > On Mon, Nov 19, 2007 at 11:38:08PM +0900, Shuaib Zahda wrote:
> > > Hi all
> > >
> > > I was trying to find a method to read only the last line of a file. I
> > > checked the the documentation and there is no such method.
> > > Beside reading line after line and checking the the eof method. Is there
> > > any faster or shorter way to do that.
> >
> > Depending on your platform, you might find that using popen with tail -1
> > will be the fastest and easiest way. Failing that, consider this:
> >
> > last = File.open(myfile) { |f| f.extend(Enumerable).inject { |_,ln| ln } }
> 
> You do not need the ".extend(Enumerable)" bit as an IO does already
> include Enumerable:
> 
> $ ruby -e 'p Enumerable === $stdin'
> true

Ah, sorry, you are correct. For some reason I was thinking of MySQL result
sets.

> Cheers
> robert
--Greg