Could not launch application ‘hplip-systray.desktop’: Unable to start application: Failed to execute child process “hp-systray” (No such fil e or directory)

After an upgrade from Debian 9.9 to Debian 10, some errors were found in my .xsessions-errors file.

The apt-file utility provided by the Debian distribution provides an easy way to provide the matching Debian package for a given file.

To install it :

apt install apt-file

To provide it with the latest details from Debian repos :

apt-file update

To look for the corresponding Debian package that hplip-systray.desktop file belongs to :

apt-file search hplip-systray.desktop
hplip-gui: /etc/xdg/autostart/hplip-systray.desktop

To install it :

apt install hplip-gui

More details :

Details of apt-file Debian package

Details of hplip-gui Debian package

To detect whether software based rendering is needed for Qt 5 the glxinfo program is a requirement but it was not found on this system.

After an upgrade from Debian 9.9 to Debian 10, some errors were found in my .xsessions-errors file.

To detect whether software based rendering is needed for Qt 5 the glxinfo program is a requirement but it was not found on this system.

The glxinfo program is provided by the mesa-utils Debian package.

To install it :

apt install mesa-utils

More details : Details of mesa-utils Debian package

Fix auto-indentation in Vim

Here are a few VIM commands to type within the editor to check the current settings and enable what is missing to make VIM auto-indent your file.

:filetype

If disabled, the output will be :

filetype detection:ON plugin:ON indent:OFF

To enable it :

:filetype indent on

To list all the indentations file available (for any programming language for instance)

:e $VIMRUNTIME/indent

If you find one that matches the programming language that you are typing in your editor, to indent your code :

gg=G

To make it permanent, add the following line in your .vimrc file :

filetype indent on

pdflatex not found. Please select a different –pdf-engine or install pdflatex

If you use pandoc to generate a pdf file from a markdown file, you may have this warning message :

pdflatex not found. Please select a different –pdf-engine or install pdflatex

On Ubuntu 19.04, after an initial install using the distribution package manager, no pdf engine is installed.

Using the apt-file utility and searching for pdflatex, texlive-latex-base package includes it.
This package texlive-fonts-recommended will bring additional fonts.

To install it :


apt install textlive-latex-base textlive-fonts-recommended

To test the pdf output :


pandoc test.md -s -o test.pdf

How to keep date and time up to date after resuming from sleep mode

If you’re running Ubuntu Linux within a VM, time and date may not be accurate after resuming from sleep mode.

timedatectl provides a way to display and modify date and time information.

To get full details about the current date/time/time zones settings :

timedatectl status

Syncing date and time information with a ntp server is relevant.

timedatectl set-ntp true

To see the modification in effect :

timedatectl status

The NTP service information should be updated from inactive to active.

Setting up a desktop notification in Ubuntu after login

The following actions have been tested successfully on Ubuntu 19.04

Setting a desktop notification in Ubuntu after login requires creating a Desktop application following the Freedesktop specifications.
All such applications run as a user must be located in $HOME/.config/autostart

The autostart folder may not exist.
If not :

mkdir -p $HOME/.config/autostart

As an example, this desktop application will be named welcome.desktop

Create this file as follows :


touch $HOME/.config/autostart/welcome.desktop

Add the following lines in it :

cat welcome.desktop

[Desktop Entry]
Type=Application
Exec=/home/$USERNAME/Tools/
welcome_msg.sh
Hidden=false
NoDisplay=false
X-GNOME-Autostart-enabled=true
Name=myscript
Comment=Startup Script

Create the bash script welcome_msg.sh that will display the notification message :

cat welcome_msg.sh

#!/usr/bin/env bash

notify-send “Good morning ${USERNAME^} !” “Did you check your backups ?”

Make sure that the Exec field in your welcome.desktop file points to your script.

Reboot your Ubuntu machine and log in. Your custom desktop notification will be displayed !

Further readings :

https://cloudkul.com/blog/display-notification-login-ubuntu/

XDG autostart specification

Different ways of autostarting applications in Linux

Desktop Application Autostart Specification