From: Jason Creighton <androflux@...>
Date: 2003-09-18T08:32:00+09:00
Subject: Re: How do I use grep with the Shell class

On Wed, 17 Sep 2003 14:13:57 +0900
Mark Wilson <mwilson13@cox.net> wrote:

> Hello,
> 
> I'm trying to do the following in Ruby using the Shell class:
> 
>  From the command line, I would write this:
> 
> % grep -l PATTERN * | xargs mv --target-directory=DIRECTORY
> 
> Because I have many directories I want to visit in turn, I've tried the 
> following:
> 
> directories.each do |d|
>    shell = Shell.cd(d)
>    string = String.new
>    shell.transact do
>      string = shell.grep("-l", "PATTERN", "*")  # => the '*' is not 
> expanded;
>                                                                    # 
> grep: *: No such file or directory
>    end
>    array = string.split
>    array.each { |e| File.move(e, "DIRECTORY") }
> end
> 
> The above does not work. Does anyone have any insight (or alternate 
> ways to accomplish the same purpose in Ruby)?

Something like this, perhaps?

directories.each do |d|
  Dir["#{d}/*"].each do |filename|
    f = File.open(filename)
    if f.detect { |line| line =~ /PATTERN/ }
      File.rename(filename, File.join("DIRECTORY", File.basename(filename)))
    end
    f.close()
  end
end

Using the command line would probably be easier for a quick job like
this, however. (Unless you really need to do this from within Ruby)

Jason Creighton