Dir.bitbucket?

ruby-talk
1

Hi all,

Occasionally I have to do something like this:

bitbucket = RUBY_PLATFORM.match('mswin') ? 'NUL' : '/dev/null'

How about a Dir.bitbucket method? Or Dir.null, or whatever you want to call it.

I think the code, using pure Ruby, would look like this:

case RUBY_PLATFORM
   when /mswin/i
      'NUL'
   when /amiga/i
      'NIL:'
   when /openvms/i
      'NL:'
   else
      '/dev/null'
end

I based this on http://en.wikipedia.org/wiki//dev/null

Useful? If so, we could easily patch dir.c, though I'm not sure what the best way to approach it would be, i.e. should we do platform checks within the code or rely on constants set during the build phase?

Regards,

Dan

2

it's not quite the same thing, since it's not a part of the Ruby core, but I've got a library, Facter[1], specifically meant to help handle this kind of platform variety. This kind of simple code would look like this:

Facter.add :bitbucket do
  setcode do
    case Facter.operatingsystem
    when /mswin/i: 'NUL'
    when /amiga/i: 'NIL'
    when /openvms/i: 'NL:'
    else
      '/dev/null'
    end
  end
end

The reason the code is set separately is that, for more complicated facts, you could have a separate resolution mechanism for every platform:

Facter.add :bitbucket do
  confine :operatingsystem => :mswin
  setcode { "NUL" } # strings get executed as shell code, so you have to use a block
end

Facter.add :bitbucket do
  confine :operatingsystem => :amiga
  setcode { "NIL" }
end
...

Any fact can be be confined based on other facts, so you could confine a fact to work only on a given release of a specific platform (e.g., Mac OS X seems to change the config file that stores the IP configuration on every release).

The interface could probably be slimmed down some, but the basic idea is there: Make it simple to get a fact on different platforms. It's especially useful for things like domain names, which can often be resolved multiple ways (/etc/resolv.conf, /bin/domainname, dns, /etc/hosts, etc.)

1 - http://reductivelabs.com/projects/facter

···

On Aug 19, 2006, at 11:34 PM, Daniel Berger wrote:

Hi all,

Occasionally I have to do something like this:

bitbucket = RUBY_PLATFORM.match('mswin') ? 'NUL' : '/dev/null'

How about a Dir.bitbucket method? Or Dir.null, or whatever you want to call it.

--
Luke Kanies
http://madstop.com | http://reductivelabs.com | 615-594-8199