From: Robert Klemme <shortcutter@...>
Date: 2007-04-28T21:55:04+09:00
Subject: Re: Editing a text file

On 28.04.2007 02:15, barjunk wrote:
> There is a task to edit a text file.  It is entirely possible that
> multiple people are going to be running the ruby script that edits
> this file at the same time.
> 
> I have looked at Ruby cookbook recipe 6.13 and 20.11.  These seem like
> what I am wanting.
> 
> It seemed like a good idea to float this as a solution before it is
> implemented.
> 
> How I do it now is using sed:
> 
> flock $USERFILE sed -i \
>   "/^$1[[:space:]]\+/,+6 { s/^\\(.*Default\\)/#\\1/; s/^#\\(.*SRT\\)/\
> \1/; }" \
>    $USERFILE
> 
> But I'd like to move this piece of code into the ruby script instead
> of launching it with a system command.
> 
> What other ways are people doing this sort of thing?
> 
> BTW, for those of you that don't have the cookbook, it basically
> redefines open to include a flock call.

I consider Ara the definitive source especially when it comes to 
flock'ing NFS mounted files, see for example:

http://blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-talk/97211

For the low profile solution check out

http://ruby-doc.org/core/classes/File.html#M002576

Kind regards

	robert