Thomas' Wiki - public

Automatically assigning extensions to files

Anonymous (anonymous@undisclosed.example.com) — 2026-02-23T10:39:37+00:00

Automatically assigning extensions to files #recursively find files in current directory that have no extension for i in $(find . -type f ! -name "*.*"); do #guess that extension using file extfile=$(file --extension --brief $i) #select the first extension in the event file spits something weird (e.g. jpeg/jpe/jfif) extawk=$(echo $extfile | awk -F/ '{print $1}') #copy the file to a file appended with the extension guessed from the former commands mv $i $i.$extawk done

Anonymous (anonymous@undisclosed.example.com) — 2024-08-05T18:43:19+00:00

You can use wodim for this: Install it with: apt install wodim Then burn your image: wodim -eject -tao speed=2 dev=/dev/sr0 -v -data image.iso wodim cdrom

Checking if a file exists with PowerShell

Anonymous (anonymous@undisclosed.example.com) — 2024-04-17T12:54:05+00:00

Checking if a file exists with PowerShell You can check the existence of a file with the Test-Path command: Test-Path -Path C:/Path/To/File The command will return a boolean. powershell

Common OpenSSL Operations

Anonymous (anonymous@undisclosed.example.com) — 2024-11-20T08:38:05+00:00

Common OpenSSL Operations Extracting a private key in PEM format from a P12 container openssl pkcs12 -in container.p12 -out key.pem -legacy -nocerts -nodes Extracting a certificate in PEM format from a P12 container openssl pkcs12 -in container.p12 -out certificate.pem -legacy -nokeys -nodes

Common patterns in PowerShell

Anonymous (anonymous@undisclosed.example.com) — 2024-04-17T13:16:20+00:00

Common patterns in PowerShell Getting help on a cmdlet You can use the Get-Help command to get the Powershell alternative of a man page. E.g.: Get-Help "Test-Path' The first time you use Get-Help, PowerShell may need some time to download necessary help files.

Creating a disk image

Anonymous (anonymous@undisclosed.example.com) — 2024-04-02T21:19:30+00:00

Creating a disk image With dd dd if=/dev/sdc of=output.img bs=512 conv=sync,noerror draft

Da Rules

Anonymous (anonymous@undisclosed.example.com) — 2024-11-13T22:40:39+00:00

Da Rules * Nothing is more permanent than a temporary solution. * Meetings with more than 4 people are rather pointless. * Avoid starting from scratch. Incrementally improve what already exists.

Disabling mouse support in VIM

Anonymous (anonymous@undisclosed.example.com) — 2024-06-07T07:58:21+00:00

Disabling mouse support in VIM Vim nowadays supports your mouse in the terminal. Unfortunately, it interferes when simply selecting text for other purposes. You can disable mouse support in VIM by: Executing the following one-off command in VIM: :set mouse=

Downloading with cURL

Anonymous (anonymous@undisclosed.example.com) — 2024-05-13T09:47:14+00:00

Downloading with cURL You can download a file with cURL by using this command: curl -LO The L options tells cURL to follow any redirects, if needed. The O option tells it to download to a file instead of stdout.

Setting SPF and DMARC for a domain that is not sending e-mail

Anonymous (anonymous@undisclosed.example.com) — 2025-12-17T08:39:00+00:00

Setting SPF and DMARC for a domain that is not sending e-mail Set the SPF TXT record (domain.com) to: v=spf1 -all This will inform receiving mail servers that no servers are authorized to send mail from this domain. Set the DMARC TXT record (_dmarc.domain.com) to:

Enabling SSH on macOS via Terminal

Anonymous (anonymous@undisclosed.example.com) — 2024-04-03T09:56:07+00:00

Enabling SSH on macOS via Terminal Turn on SSH Enable the SSH service: sudo /usr/sbin/systemsetup -setremotelogin on Permit

Anonymous (anonymous@undisclosed.example.com) — 2024-03-26T11:02:46+00:00

If you want to find out what version of macOS is running on a freshly installed Mac without going through Setup Assistant, you can boot it in recovery mode and check the version by checking the volume in Disk Utility: macos disk_utility

Fixing Microsoft 365 Apps stuck updates

Anonymous (anonymous@undisclosed.example.com) — 2024-04-18T10:00:13+00:00

Fixing Microsoft 365 Apps stuck updates When you deploy the Microsoft 365 Apps (a.k.a. the normal Microsoft Office apps such as Word etc.) via Intune, you can choose which version you want to deploy using the “Version to install” option. If you change it from

Generating a random MAC address

Anonymous (anonymous@undisclosed.example.com) — 2024-05-13T09:36:48+00:00

Generating a random MAC address On Linux echo $FQDN$RANDOM|md5sum|sed 's/^$..$$..$$..$$..$$..$.*$/02:\1:\2:\3:\4:\5/' References *

Listing all Teams assigned phone numbers

Anonymous (anonymous@undisclosed.example.com) — 2024-11-07T10:50:39+00:00

Listing all Teams assigned phone numbers :!: At the time of writing, this does not yet seem possible with Graph API, and requires the Teams Powershell module instead. Open PowerShell, and install the PowerShell Teams module: Install-Module -Name MicrosoftTeams -Force -AllowClobber

List libvirt OS Variants

Anonymous (anonymous@undisclosed.example.com) — 2024-11-08T10:19:32+00:00

List libvirt OS Variants When creating a guest with virt-install you need to specify the --os-variant. To get a list of acceptable values, first install the libosinfo-bin package sudo apt install libosinfo-bin before running the command below:

Logging in on Windows 11 Remote Desktop with Your Microsoft Account

Anonymous (anonymous@undisclosed.example.com) — 2024-11-07T12:02:15+00:00

Logging in on Windows 11 Remote Desktop with Your Microsoft Account On Windows 11, if you use your Microsoft account to log in to your PC, you will be unable to log in via Microsoft Remote Desktop. As a workaround, you need to use runas to cache your Microsoft account password. After that (and of course enabling Remote Desktop), you will be able to log in remotely using your Microsoft account e-mail address and password

Looking up the hostnames for all IP addresses in a class C subnet

Anonymous (anonymous@undisclosed.example.com) — 2024-05-15T11:22:57+00:00

Looking up the hostnames for all IP addresses in a class C subnet On Linux PREFIX="192.168.0" for i in $(seq 1 254) do echo $i nslookup $PREFIX.$i done | grep name

Managing Apple Content Caching

Anonymous (anonymous@undisclosed.example.com) — 2024-04-22T14:47:26+00:00

Managing Apple Content Caching Any Mac can serve as a content cache, speeding up Apple software updates and certain types of iCloud content. Content caches can be configured graphically, via System Settings, or via the command: AssetCacheManagerUtil

Managing Google Chrome and Edge via MDM

Anonymous (anonymous@undisclosed.example.com) — 2024-07-26T11:20:52+00:00

Managing Google Chrome and Edge via MDM You can see if Google Chrome is managed by browsing to: chrome://management You can see what policies are applied by browsing to: chrome://policy Note that chrome has “recommended” settings, and regular settings. The recommended settings can be changed by the user, and are only applied when the browser is first initialized or reset.The regular settings are always applied and cannot be changed by the user.

Managing KVM on Debian

Anonymous (anonymous@undisclosed.example.com) — 2024-05-17T20:56:22+00:00

Managing KVM on Debian Installing KVM Install the required packages: sudo apt install --no-install-recommends qemu-system libvirt-clients libvirt-daemon-system virtinst qemu-utils dnsmasq swtpm swtpm-tools ovmf bridge-utils libvirt-daemon-driver-storage-zfs

Managing LUKS on Debian

Anonymous (anonymous@undisclosed.example.com) — 2024-08-05T17:04:45+00:00

Managing LUKS on Debian LUKS (Linux Unified Key Setup) is the disk encryption software that's available on Debian. It sits between the file system and the block device, and encrypts all data as it passes through. Since LUKS works directly on the block device, all commands listed below must be executed

Managing LXD (Incus) on Debian

Anonymous (anonymous@undisclosed.example.com) — 2024-05-13T09:15:06+00:00

Managing LXD (Incus) on Debian Installing Incus Debian has its own port of LXD called Incus. It can be installed by executing: sudo apt install incus Then initialize Incus: :!: Before initialization, make sure to have a network bridge and ZFS dataset ready if you want to use those.

Managing networking in Debian

Anonymous (anonymous@undisclosed.example.com) — 2024-05-16T18:21:12+00:00

Managing networking in Debian Showing info about a bridge interface brctl show This requires the bridge-utils package. Setting up VLAN interfaces In /etc/modules add the line to load the module automatically on startup: 8021q

Managing ZFS on Debian

Anonymous (anonymous@undisclosed.example.com) — 2024-05-03T21:29:25+00:00

Managing ZFS on Debian Installing ZFS First, make sure your system is up-to-date and restarted. This prevents compilation issues later on. Then, add the contrib section to your apt sources configuration. It should look similar to this: # deb cdrom:[Debian GNU/Linux 12.5.0 _Bookworm_ - Official amd64 DVD Binary-1 with firmware 20240210-11:28]/ bookworm contrib main non-free-firmware deb http://deb.debian.org/debian/ bookworm main non-free-firmware contrib deb-src http://deb.debian.org/debia…

Opening DMG disk images via Terminal

Anonymous (anonymous@undisclosed.example.com) — 2024-04-03T07:30:21+00:00

Opening DMG disk images via Terminal You can open disk images via Terminal using the following command: hdiutil attach /path/to/image.dmg Good to know: you can also specify a HTTP URL to open the disk image directly from the web, without downloading it.

Dependencies

Anonymous (anonymous@undisclosed.example.com) — 2024-06-23T19:35:01+00:00

Dependencies brew install nasm make qemu Boot qemu with floppy image: qemu-system-i386 -fda build/main_floppy.img

Parsing a CSV File with Bash

Anonymous (anonymous@undisclosed.example.com) — 2024-11-09T10:06:49+00:00

Parsing a CSV File with Bash You can easily parse CSV files with bash. In this example script, I generate QR codes using qrencode as an example. As a source I use following very simple CSV file called list.csv: Google,https://www.google.com Yahoo,https://www.microsoft.com Microsoft,https://www.microsoft.com

Repackaging Isabel Security Components for macOS

Anonymous (anonymous@undisclosed.example.com) — 2024-04-05T08:43:03+00:00

Repackaging Isabel Security Components for macOS Why repackage? The macOS installer of Isabel has some major deficiencies. It tries to access resources not in its installer, tries to manipulate the Dock of the active user, tries to interact with Finder, and uses the

Ripping a video from a website

Anonymous (anonymous@undisclosed.example.com) — 2024-05-04T12:57:41+00:00

Ripping a video from a website :!: If your browser indicates that any kind of DRM is in use, such as WideVine or FairPlay, these instructions will not be sufficient, as those videos are encrypted. If a website has a video you'd like to download, try the obvious methods first:

Setting up a watch-only Bitcoin wallet

Anonymous (anonymous@undisclosed.example.com) — 2024-08-02T22:07:27+00:00

Setting up a watch-only Bitcoin wallet On an airgapped computer First, set up a new wallet the usual way. Then, export the descriptors for that wallet via the following console command: listdescriptors :!: Do not add true as a parameter, as that would also export your private key descriptors!

Unblocking all files in a folder recursively on Windows

Anonymous (anonymous@undisclosed.example.com) — 2024-05-22T14:53:30+00:00

Unblocking all files in a folder recursively on Windows Use Powershell: Get-ChildItem -Path 'C:\Path\To\Folder' -Recurse | Unblock-File windows powershell

Unifi Security Gateway DHCP server stops working

Anonymous (anonymous@undisclosed.example.com) — 2024-04-12T08:20:55+00:00

Unifi Security Gateway DHCP server stops working I recently experienced an issue where the DHCP server of my Unifi Security Gateway stopped working. For some reason, clients were not receiving IP addresses anymore. Earlier that day, I had assigned a fixed IP to a host, so maybe that screwed up the configuration at some point, but it's difficult to say for sure.

Unlocking Debian LUKS with a Yubikey at boot

Anonymous (anonymous@undisclosed.example.com) — 2024-03-22T23:20:36+00:00

Unlocking Debian LUKS with a Yubikey at boot You can use a Yubikey to unlock a Debian system at boot. For general info on managing LUKS, see Managing LUKS on Debian. On the Yubikey You must set up your Yubikey with the challenge-response algorithm in slot 2. One of the methods of doing so is using Yubico Authenticator.

Using LUKS on a floppy drive

Anonymous (anonymous@undisclosed.example.com) — 2024-04-02T21:18:20+00:00

Using LUKS on a floppy drive Make sure the disk is unmounted: umount /dev/sdc Format the drive as a LUKS volume: cryptsetup luksFormat -v --type luks2 --luks2-keyslots-size 4k /dev/sdc draft

Using nmap

Anonymous (anonymous@undisclosed.example.com) — 2024-05-23T11:47:23+00:00

Using nmap Scanning a single host nmap nmap

Using robocopy

Anonymous (anonymous@undisclosed.example.com) — 2024-03-21T15:51:10+00:00

Using robocopy Robocopy is a Windows command line tool that can be used to robustly copy files. It's a bit similar to rsync on UNIX platforms. To mirror a folder robocopy C:\Folder1\ D:\Folder2\ /MIR /XO Meaning of the options: * /MIR: Mirrors the source to the destination.

Using SSH agent forwarding

Anonymous (anonymous@undisclosed.example.com) — 2024-06-07T07:25:52+00:00

Using SSH agent forwarding SSH agent forwarding allows you to use your local SSH keys on a remote host, when using it to connect to yet another host. You can either define this in your ~/.ssh/config file with a host specific section: Host example.com ForwardAgent yes

virt-install examples

Anonymous (anonymous@undisclosed.example.com) — 2024-05-16T21:27:02+00:00

virt-install examples MS-DOS 6.0 virt-install \ --virt-type kvm \ --name msdos-test \ --os-variant msdos6.22 \ --graphics vnc,listen=0.0.0.0,password=foobar --noautoconsole \ --disk size=2 \ --memory 32 \ --disk path=/dos/Disk1.img,device=floppy \ --boot fd,hd,menu=on \ --import

Working with CD-ROMs in Linux

Anonymous (anonymous@undisclosed.example.com) — 2024-04-12T08:22:01+00:00

Working with CD-ROMs in Linux Ejecting a CD-ROM Simply use tje eject command. eject References linux cd-rom

Working with systemd

Anonymous (anonymous@undisclosed.example.com) — 2024-05-11T09:49:54+00:00

Working with systemd Starting or stopping a service systemctl start systemctl stop Enabling or disabling a service systemctl enable systemctl disable systemd