Ruby fstab ffi implementation for unix (mac os x / bsd)

fstab.rb

require "ffi"

module Mount
  class Fstab < FFI::Struct
    layout :fs_spec,    :string, # block special device name
           :fs_file,    :string, # file system path prefix
           :fs_vfstype, :string, # File system type, ufs, nfs
           :fs_mntops,  :string, # Mount options ala -o
           :fs_type,    :string, # FSTAB_* from fs_mntops
           :fs_freq,    :int,    # dump frequency, in days
           :fs_passno,  :int     # pass number on parallel fsck
  end
  
  class Volume < Struct.new(:name, :path, :type, :options, :type, :freq, :pass)
  end
  
  extend FFI::Library
  ffi_lib FFI::Library::LIBC
  attach_function :getfsent, [], :pointer
  attach_function :endfsent, [], :void
  
  def self.fstab
    volumes = []
    while !(fstab = getfsent).null?
      fstab = Mount::Fstab.new(fstab)
      volumes << Volume.new(fstab[:fs_spec],
                            fstab[:fs_file],
                            fstab[:fs_vfstype],
                            fstab[:fs_mntops],
                            fstab[:fs_type],
                            fstab[:fs_freq],
                            fstab[:fs_passno])
    end
    volumes
  ensure
    endfsent
  end
end