From: Robert Dober <robert.dober@...>
Date: 2009-08-07T18:59:26+09:00
Subject: Re: FFI, sysctl, pointer question

On Fri, Aug 7, 2009 at 10:22 AM, Daniel Berger<djberg96@gmail.com> wrote:
At first sight you need MemoryPointer, but I could not really get it
working, but probably I screwed the sysctl call, I did not find a
reference of it for my system. Well for what it is worth I'll share
what I did.
*N.B.*  This fails with
ffi1.rb:35:in `seconds': unknown error - sysctl() (SystemCallError)
	from ffi1.rb:43:in `<main>'

    def self.seconds
        tv  = Timeval.new
        mib = [CTL_KERN, KERN_BOOTTIME]

        # What's the proper way to call this?
        tvp = FFI::MemoryPointer::new :pointer
        tvp.put_pointer 0, tv
        mip = FFI::MemoryPointer::new :int, 2
        mip.put_array_of_int 0, mib
        if sysctl(mip, 2, tv, tvp, nil, 0) != 0
           raise SystemCallError, 'sysctl()'
        end

        time(nil) - tv[:tv_sec]
end

Maybe somebody can spot my error(s) ;)

Cheers
Robert

-- 
module Kernel
  alias_method :ë, :lambda
end