module Facter::Bsd::FfiHelper

Public Class Methods

sysctl(type, oids) click to toggle source
# File lib/facter/resolvers/bsd/ffi/ffi_helper.rb, line 14
def self.sysctl(type, oids)
  name = FFI::MemoryPointer.new(:uint, oids.size)
  name.write_array_of_uint(oids)
  namelen = oids.size

  oldp = FFI::Pointer::NULL
  oldlenp = FFI::MemoryPointer.new(:size_t)

  newp = FFI::Pointer::NULL
  newlen = 0

  if type == :string
    res = Libc.sysctl(name, namelen, oldp, oldlenp, newp, newlen)
    return nil if res.negative?
  else
    oldlenp.write(:size_t, FFI.type_size(type))
  end

  oldp = FFI::MemoryPointer.new(:uint8_t, oldlenp.read(:size_t))
  res = Libc.sysctl(name, namelen, oldp, oldlenp, newp, newlen)
  return nil if res.negative?

  case type
  when :string
    oldp.read_string
  else
    oldp.read(type)
  end
end