Nikolaos Dimopoulos niden

Signing VirtualBox Kernel Modules

These are the steps I followed enable VirtualBox on my laptop without disabling UEFI Secure Boot. They're nearly identical to the process described on [Øyvind Stegard's blog][blog], save for a few key details. The images here are borrowed from the [Systemtap UEFI Secure Boot Wiki][systemtap].

Install the VirtualBox package (this might be different for your platform).

src='https://download.virtualbox.org/virtualbox/rpm/fedora/virtualbox.repo'

Multiple PHP versions using `phpenv` and `php-build`

Install dependecies

Debian/Ubuntu users

sudo apt install \
  autoconf \
  bison \

Order of evaluation in PHP

Yesterday I found some people on my [favorite reddit][lolphp] wonder about the output of the following code:

<?php

$a = 1;
$c = $a + $a++;

Why objects (usually) use less memory than arrays in PHP

This is just a small post in response to [this tweet][tweet] by Julien Pauli (who by the way is the release manager for PHP 5.5). In the tweet he claims that objects use more memory than arrays in PHP. Even though it can be like that, it's not true in most cases. (Note: This only applies to PHP 5.4 or newer.)

The reason why it's easy to assume that objects are larger than arrays is because objects can be seen as an array of properties and a bit of additional information (like the class it belongs to). And as array + additional info > array it obviously follows that objects are larger. The thing is that in most cases PHP can optimize the array part of it away. So how does that work?

The key here is that objects usually have a predefined set of keys, whereas arrays don't:

	# *****************************************************************************
	# UPDATED VERSION AVAILABLE HERE:
	# https://github.com/LeCoupa/awesome-cheatsheets/blob/master/tools/nanobox_cli.sh
	# *****************************************************************************


	# *****************************************************************************
	# LOCAL ENVIRONMENT
	# *****************************************************************************

	## Configure eth0
	#
	# vi /etc/sysconfig/network-scripts/ifcfg-eth0

	DEVICE="eth0"
	NM_CONTROLLED="yes"
	ONBOOT=yes
	HWADDR=A4:BA:DB:37:F1:04
	TYPE=Ethernet
	BOOTPROTO=static

	<?php
	/**
	* CIDR.php
	*
	* Utility Functions for IPv4 ip addresses.
	* Supports PHP 5.3+ (32 & 64 bit)
	* @author Jonavon Wilcox <[email protected]>
	* @revision Carlos Guimarães <[email protected]>
	* @version Wed Mar 12 13:00:00 EDT 2014
	*/