Linux on Notities

Deskflow: Control multiple computers with 1 keyboard and mouse for: macOS, Windows and Linux

Mon, 24 Mar 2025 17:57:51 +0000

With Deskflow you control multiple computers — macOS, Windows or Linux — using a single mouse and keyboard. It works as a software-based KVM switch (without video) and is sponsored by Synergy. This program is still actively maintained, with an intuitive interface that makes it easy to use. Tip: disable TLS in the settings for a smooth start.

Download it via: https://github.com/deskflow/deskflow/releases. Look for the “latest” tag and check all assets for the correct version!

Installing Oracle VirtualBox on Ubuntu Linux

Sun, 23 Mar 2025 13:20:53 +0000

Try the following steps:

$ sudo apt update
$ sudo apt upgrade
$ sudo apt install curl
$ curl -fsSL https://www.virtualbox.org/download/oracle_vbox_2016.asc | sudo gpg –dearmor -o /usr/share/keyrings/virtualbox-archive-keyring.gpg
$ echo “deb [arch=amd64 signed-by=/usr/share/keyrings/virtualbox-archive-keyring.gpg] http://download.virtualbox.org/virtualbox/debian noble contrib” | sudo tee /etc/apt/sources.list.d/virtualbox.list
$ sudo apt update
$ sudo search virtualbox

virtualbox/noble-updates 7.0.16-dfsg-2ubuntu1.1 amd64 x86 virtualization solution - base binaries

virtualbox-7.0/unknown 7.0.24-167081~Ubuntu~noble amd64 Oracle VM VirtualBox

virtualbox-7.1/unknown 7.1.6-167084~Ubuntu~noble amd64 Oracle VirtualBox

$ sudo install virtualbox-7.1

Download the Extension Pack frm the website: https://www.virtualbox.org/wiki/Downloads

Tips for using XRDP on Ubuntu Linux

Sun, 23 Mar 2025 12:51:59 +0000

To be able to use XRDP on Ubuntu Linux try the following instructions:

$ sudo apt update
$ sudo apt upgrade
$ sudo apt install xrdp
$ echo “gnome-session –session=ubuntu” > ~/.xsession
$ echo “export DISPLAY=:10.0” > ~/.bash_profile
$ echo “xhost +” > ~/.bash_profile
$ ip a

Remember write down your IP address of your system and to log out of your graphical user session.

Now try to login to your system with a RDP tool.

Install Microsoft Visual Studio Code in Linux from the repo

Sat, 22 Mar 2025 22:13:54 +0000

Follow the below steps to install Microsoft Visual Studio Code IDE on Linux from its repository:

sudo rpm –import https://packages.microsoft.com/keys/microsoft.asc

sudo sh -c ’echo -e “[code]\nname=Visual Studio Code\nbaseurl=https://packages.microsoft.com/yumrepos/vscode\nenabled=1\ngpgcheck=1\ngpgkey=https://packages.microsoft.com/keys/microsoft.asc” > /etc/yum.repos.d/vscode.repo'

sudo dnf install code -y

LDAP/IPA - Server on Red Hat Enterprise Linux 7

Thu, 15 Feb 2024 10:47:28 +0000

If you are using a hosts file, make sure it contains FQDNs and pay close attention to the order in which they appear.

Check the hosts file and adjust it if necessary:

The FQDN must come first, followed by any aliases.

/etc/hosts

10.0.0.1 server1.example.com server1 application1

If an alias is listed before the FQDN, you may encounter error messages that are not immediately traceable to this cause.

Create a Zombie process in Linux using a C program

Wed, 31 Jan 2024 20:54:45 +0000

Below is the source code of a C program to create a Zombie process in Linux and analyse it.

vim create_zombie_process.c

#include <stdlib.h>
#include <sys/types.h>
#include <unistd.h>

int main ()
{
 pid_t child_pid;

 child_pid = fork ();
 if (child_pid > 0) {
 sleep (60);
 }
 else {
 exit (0);
 }
 return 0;
}

Compile the C source code into an executable program:

gcc create_zombie_process.c

Start the program:

./a.out

Open a second Terminal and view the process list. You will now see a process with STAT: Z and the text: defunct

Checkmk installation on Rocky Linux 9.3

Tue, 16 Jan 2024 21:13:15 +0000

Checkmk installation on Rocky Linux 9.3

dnf install epel-release

setsebool -P httpd_can_network_connect 1

firewall-cmd --zone=public --add-service=http --permanent
firewall-cmd --reload

wget https://download.checkmk.com/checkmk/2.2.0p18/check-mk-raw-2.2.0p18-el9-38.x86_64.rpm
yum install check-mk-raw-2.2.0p18-el9-38.x86_64.rpm

omd version
omd create monitoring
omd start monitoring

http://localhost.localdomain/monitoring/
user: cmkadmin with password: <given>

omd su monitoring (For command line administration of the site.)
cmk-passwd cmkadmin (After logging in, you can change the password for cmkadmin with.)

(optional)
omd status
omd sites
omd help

(optional for after reboot if you get the error: Unable to connect)
omd update-apache-config monitoring

Installing the VirtualBox Guest Additions on Rocky Linux 9.3

Tue, 16 Jan 2024 21:08:26 +0000

Installing the VirtualBox Guest Additions on Rocky Linux 9.3

dnf install epel-release
dnf update --refresh
dnf update kernel-*
reboot (optional)

dnf install dkms kernel-devel kernel-headers gcc make bzip2 perl elfutils-libelf-devel

rpm -q kernel-devel
uname -r

Top menu: Devices -> Insert Guest Additions CD-Image
Run

(optional)
cd /run/media/
./VBoxLinuxAdditions.run

The Linux mlocate command on macOS

Wed, 27 Sep 2023 17:40:13 +0000

The Linux mlocate command under macOS

sudo /usr/libexec/locate.updatedb

sudo ln -s /usr/libexec/locate.updatedb /usr/local/bin/updatedb

Linux disk space information more clearly excluding the denied and cannot messages

Tue, 05 Sep 2023 06:23:38 +0000

$ du -hs * 2> >(egrep -iv ‘permission denied|cannot access’) | sort -n

Linux locate lost storage space difference between results df and du

Tue, 05 Sep 2023 06:18:17 +0000

$ lsof | grep -E ‘^COM|deleted’

Automatically log in to a Linux server using PuTTY on Windows

Fri, 17 Feb 2023 14:51:15 +0000

You can automatically log in to a Linux server on Windows using PuTTY by making use of a key file. Below I explain step by step how to do this.

Create a key: start: puttygen.exe
Click on: Generate
Click on: Save private key
Go to PuTTY Configuration -> Session
Load a previously created session or create a new one
Go to: Connection -> SSH -> Auth -> Private key file for authentication -> Browse
Select your file with the private key: *.ppk
Go back to Session and click on: Save
Log in to the Linux server using the Saved Sessions and still with your password
Create a new directory in the home directory: .ssh
Give this directory the correct permissions: chmod 700 ~/.ssh
Create and edit the file authorized_keys: vi ~/ssh/authorized_keys
Copy the Public key for pasting from the PuTTY Key Generator
Paste it into the authorized_keys file on the Linux server
Save the authorized_keys file (for vi type: :wq)
Give this file the correct permissions: chmod 600 ~/.ssh/authorized_keys
Close the logged-in PuTTY session to the Linux Server
Open the session again to verify that you can now log in automatically

Install Python 3.9 on Ubuntu Linux

Sun, 03 Apr 2022 18:55:18 +0000

$ sudo apt install software-properties-common

$ sudo add-apt-repository ppa:deadsnakes/ppa

$ sudo apt update

$ sudo apt install python3.9

$ python3.9 –version

Install the editor VSCodium on Ubuntu Linux

Sun, 03 Apr 2022 14:22:24 +0000

$ wget -qO - https://gitlab.com/paulcarroty/vscodium-deb-rpm-repo/raw/master/pub.gpg | sudo apt-key add -

$ sudo echo ‘deb https://vscodium.c7.ee/debs/ vscodium main’ | sudo tee –append /etc/apt/sources.list.d/vscodium.list

$ sudo apt update

$ sudo apt install codium

Install the Google Chrome Web Browser on Ubuntu Linux

Sun, 03 Apr 2022 11:51:54 +0000

$ wget -q -O - https://dl.google.com/linux/linux_signing_key.pub | sudo apt-key add -

$ sudo sh -c ’echo “deb [arch=amd64] http://dl.google.com/linux/chrome/deb/ stable main” » /etc/apt/sources.list.d/google-chrome.list'

$ sudo apt update

$ sudo apt install google-chrome-stable

New life in an old Apple computer (iMac, MacBook)

Fri, 25 Feb 2022 11:09:02 +0000

Install the VirtualBox application and run a virtual machine inside it with the latest version of Linux or Windows. In many cases this can solve problems with browsing the internet — for example, making it possible to visit websites that no longer work in the old Apple environment.