From: Joel VanderWerf <joelvanderwerf@...>
Date: 2013-07-02T01:40:55+09:00
Subject: Re: including FileUtils::Verbose crashes Marshal.dump

On 07/01/2013 09:22 AM, Bryan Lockwood wrote:
...
> My problem was that I read about fileutils in the pickaxe book (for 1.9 and 2.0), and the example included FileUtils::Verbose,
> and I figured that would be fine for starters, as I could then see what it was doing.

That example[1] seems to have been written with brevity in mind. It's ok 
in a 10 line script to include modules globally. In general, one must be 
careful, for reasons like the one you found. The internal state managed 
by those modules can interact badly with the internal state of other 
classes. It's better, though more verbose, to call methods on the module:

FileUtils.cp(....)

An exception would be if you were designing a class as a command 
language, like rake. But in that case, you would only include FileUtils 
into that class, not globally.


[1] Here's the Pickaxe example:

require 'fileutils'
include FileUtils::Verbose
cd("/tmp") do
cp("/etc/passwd", "tmp_passwd")
chmod(0666, "tmp_passwd")
cp_r("/usr/include/net/", "headers")
rm("tmp_passwd")
# Tidy up
rm_rf("headers")
end