From: DMisener <DAMisener@...>
Date: 2008-09-23T03:36:57+09:00
Subject: Re: at_exit handler *except* for fatal runtime error

On Sep 22, 1:27 pm, "ara.t.howard" <ara.t.how...@gmail.com> wrote:
> On Sep 22, 2008, at 9:51 AM, DMisener wrote:
>
> > Simple problem:
>
> > Create a tentative output working file.  If the program exits
> > "cleanly" then rename the work file
> > to its "final" name.  If not leave the work file for possible
> > examination.
>
> > Ideally this File.open_tentative_output_file would be plug
> > "compatible" with the simple File.open
> > (i.e. support modes and blocks).
>
> class TentativeFile
>    Ext = 'tentative'
>
>    def open path, *a, &b
>      super "#{ path }.#{ Ext }", *a, &b
>    end
>
>    def close
>       final = path.to_s.sub %r/[.]#{ Ext }$/, ''
>       super
>    ensure
>      File.rename path, final unless $!
>    end
> end


output=TentativeFile.new.open('temp.tmp','w')
output.puts 'Thanks'

without an explict close doesn't automatically rename the file to its
proper form.

With "regular" File.open ... the file is automatically closed without
need of explicit close. That was
the behaviour I was trying to emulate.  I'm starting to think this
"frill" is a lost cause.