From: Daniel Berger <djberg96@...>
Date: 2008-05-29T03:34:38+09:00
Subject: Re: Ensuring only one instance of a script is running



On May 20, 11:18 pm, Heesob Park <pha...@gmail.com> wrote:
> DanielBergerwrote:
> > Hi all,
>
> > I'm probably late to the game on this, but I stumbled across an
> > interesting use for DATA. You can use it to ensure only one instance
> > of a given script is running by using flock:
>
> > class Foo
> >    def self.mainloop
> >       while true
> >          puts "Looping..."
> >          sleep 3
> >       end
> >    end
> > end
>
> > DATA.flock(File::LOCK_EX)
>
> I think the above is actually equal to
>
> File.new($0).flock(File::LOCK_EX)

It would seem so. Sean O'Halpin has expanded on it a bit, too.

Regards,

Dan