vendor/bundle/ruby/2.4.0/gems/rb-inotify-0.9.10/lib/rb-inotify/native.rb

require 'ffi'

module INotify
  # This module contains the low-level foreign-function interface code
  # for dealing with the inotify C APIs.
  # It's an implementation detail, and not meant for users to deal with.
  #
  # @private
  module Native
    extend FFI::Library
    ffi_lib FFI::Library::LIBC
    begin
      ffi_lib 'inotify'
    rescue LoadError
    end

    # The C struct describing an inotify event.
    #
    # @private
    class Event < FFI::Struct
      layout(
        :wd, :int,
        :mask, :uint32,
        :cookie, :uint32,
        :len, :uint32)
    end

    attach_function :inotify_init, [], :int
    attach_function :inotify_add_watch, [:int, :string, :uint32], :int
    attach_function :inotify_rm_watch, [:int, :uint32], :int
    attach_function :fpathconf, [:int, :int], :long

    attach_function :read, [:int, :pointer, :size_t], :ssize_t
    attach_function :close, [:int], :int
  end
end