From: Dave Burt <dave@...>
Date: 2006-06-22T23:56:20+09:00
Subject: Re: disk_free_space

Darken wrote:
> I need an equivalent of $subj php function in ruby... I have a directory
> and I need to find out how much I can save there... Only idea I have is
> to find mountpoint and then parse /proc, but it's very ugly solution :-)

You can do this simply if not truly portably like so:

class << self
  define_method :disk_free_space, &begin
    require 'Win32API'
    df = Win32API.new("kernel32", "GetDiskFreeSpaceEx", "pppp", "i")
    proc do |dir|
      df.call(dir, ret="    ", "    ", "    ")
      ret.unpack("L")[0]
    end
  rescue LoadError
    proc do |dir|
      `df -k #{dir}`[/\S+\s+\S+\s+\S+\s+(\d+)/, 1].to_i * 1024
    end
  end
end

Obviously if your `df -k foo` gives you output in a different format,
you'll need to change the regular expression. (The way I've written it,
it's looking for available space in 1k blocks in the fourth column.)

Cheers,
Dave