Giovanni Grieco GiovanniGrieco

A simple Ghostscript command to merge two PDFs in a single file is shown below:

gs -dNOPAUSE -sDEVICE=pdfwrite -sOUTPUTFILE=combine.pdf -dBATCH 1.pdf 2.pdf

Install Ghostscript:

Type the command sudo apt-get install ghostscript to download and install the ghostscript package and all of the packages it depends on.

README

Services declared as oneshot are expected to take some action and exit immediatelly (thus, they are not really services, no running processes remain). A common pattern for these type of service is to be defined by a setup and a teardown action.

Let's create a example foo service that when started creates a file, and when stopped it deletes it.

Define setup/teardown actions

Create executable file /opt/foo/setup-foo.sh:

Run sudo vim /etc/default/grub
Find GRUB_CMDLINE_LINUX_DEFAULT
Append video=hyperv_fb:[the resolution you want], for example: GRUB_CMDLINE_LINUX_DEFAULT="quiet splash video=hyperv_fb:1920x1080"
Write the changes, quit Vim
Run sudo update-grub
Run sudo reboot

h/t https://blogs.msdn.microsoft.com/virtual_pc_guy/2014/09/19/changing-ubuntu-screen-resolution-in-a-hyper-v-vm/

Create Root CA (Done once)

Create Root Key

Attention: this is the key used to sign the certificate requests, anyone holding this can sign certificates on your behalf. So keep it in a safe place!

openssl genrsa -des3 -out rootCA.key 4096

Pandoc Setup

Description

A simple setup for Sublime to jot down notes in Markdown and compile a nice PDF with LaTeX through Pandoc conversion.

Why? Markdown is quick and easy to write, LaTeX is more of a hassle. But LaTeX produces nice PDFs. Using Pandoc, you can utilize the best features of both worlds by writing in markdown and compiling PDFs with LaTeX, with a simple one-click in your editor. This works fairly well for simple documents and pandoc supports most of Markdown syntax, in addition to supporting a range of variables set in a YAML meta block. Did I mention that it also supports writing LaTeX-style math and other LaTeX-commands in your Document? (Like this: $e^{i\pi}+1 = 0$ )

The output PDF is a A4 paper with 12pt font and 1 inch margins. It uses fancyhead to style the header and footer with date, pagenumbering and title/author. (This can be changed in your Pandoc-settings)

How to reduce size of docker data volume in Docker Desktop for Windows v2

Docker Desktop for Windows v2, which uses WSL2, stores all image and container files in a separate virtual volume (vhdx). This virtual hard disk file can automatically grow when it needs more space (to a certain limit). Unfortunately, if you reclaim some space, i.e. by removing unused images, vhdx doesn't shrink automatically.

Optimize

wsl --shutdown
Optimize-VHD -Path "$($env:LOCALAPPDATA)\Docker\wsl\data\ext4.vhdx" -Mode Full

Security Advisories / Bulletins / vendors Responses linked to Log4Shell (CVE-2021-44228)

Errors, typos, something to say ?

If you want to add a link, comment or send it to me
Feel free to report any mistake directly below in the comment or in DM on Twitter @SwitHak

Other great resources

Royce Williams list sorted by vendors responses Royce List
Very detailed list NCSC-NL
The list maintained by U.S. Cybersecurity and Infrastructure Security Agency: CISA List

	function Send-UdpDatagram
	{
	Param ([string] $EndPoint,
	[int] $Port,
	[string] $Message)

	$IP = [System.Net.Dns]::GetHostAddresses($EndPoint)
	$Address = [System.Net.IPAddress]::Parse($IP)
	$EndPoints = New-Object System.Net.IPEndPoint($Address, $Port)
	$Socket = New-Object System.Net.Sockets.UDPClient

	#!/usr/bin/env bash

	mac_address=$1
	# Strip colons from the MAC address
	mac_address=$(echo $mac_address \| sed 's/://g')

	broadcast=$2
	port=4343

	# Magic packets consist of 12*`f` followed by 16 repetitions of the MAC address

	USER= # your user account
	rm /run/media/$USER/__/etc/systemd/system/graphical.target.wants/initial-setup-graphical.service
	rm /run/media/$USER/__/etc/systemd/system/multi-user.target.wants/initial-setup-text.service
	mkdir /run/media/$USER/__/root/.ssh/
	cat /home/$USER/.ssh/id_rsa.pub >> /run/media/$USER/__/root/.ssh/authorized_keys
	chmod -R u=rwX,o=,g= /run/media/$USER/__/root/.ssh/