Small tricks for Ubuntu

Add a network interface (Ubuntu22) by CLI

list the interfaces

# ip link show

activate the interface

# ifconfig ens19 up

set the IP of the interface:

# nano /etc/netplan/00-installer-config.yaml

and add the interface name and the settings

apply the settings:

# netplan apply

Auto-connect VPN and Wifi

runs on Ubuntu18 LXDE

# nano /etc/lightdm/lightdm.conf.d/restart-NM.sh //// and enter in it:
#!/bin/bash
# wait 20 secondes
sleep 20s
#restart NetworkManager
service network-manager restart
exit 0

# chmod +x /etc/lightdm/lightdm.conf.d/restart-NM.sh

# nano /etc/lightdm/lightdm.conf.d/10-restart-NM.conf //// and enter in it:
[SeatDefaults]
session-setup-script=/etc/lightdm/lightdm.conf.d/restart-NM.sh

Beep

Pour activer le “beep”:

# apt-get install beep

tester si le beep fonctionne:

$ sudo modprobe pcspkr // ce réglage ne supportera pas un reboot!!
$ beep

Rendre persistant:

$ sudo nano /etc/modprobe.d/blacklist.conf
....

et commenter la ligne blacklist pcspkr

Change the keyboard layout into the login manager

works for Lubuntu20:

sudo dpkg-reconfigure keyboard-configuration

and maek your choise.

Disable the touchpad of laptops

Source: https://askubuntu.com/questions/819789/permanently-disable-touchpad-lubuntu-16-04
For “Lubuntu” (LXDE): Preferences>Default applications for LXSession>AutoStart> then “Add” synclient TouchpadOff=1

Documents management

https://gitlab.gnome.org/World/OpenPaperwork/paperwork/blob/master/flatpak/README.markdown#readme

Position of the icons on the desktop not stored

If one day all your icons are always on the left side of the desktop and their position is not remembered between the sessions: check the permissions and make a correct setting:

$ find . '!' -user $USER and look if "./.local/share/gvfs-metadata/home" is present into the list of files not owned by you
$ ls -al ./.local/share/gvfs-metadata/home will show who is the owner (generally this is "root")
$ sudo chown -R your_user_name:the_group .local/share/gvfs-metadata/home

Logout and re-login: the problem should be gone.

Remote Desktop

Via RDP
Install and run the script given here: http://c-nergy.be/blog/?p=11868
See https://help.ubuntu.com/community/xrdp too.

Run a script at startup

https://linuxconfig.org/how-to-run-script-on-startup-on-ubuntu-20-04-focal-fossa-server-desktop

$ sudo cat /usr/local/bin/wol-omv.sh
#!/bin/bash
/usr/sbin/etherwake -i enp34s0 00:11:22:33:44:55

$ sudo cat /etc/systemd/system/wol-omv.service
[Unit]
After=network-online.target
Wants=network-online.target
[Service]
ExecStart=/usr/local/bin/wol-omv.sh
[Install]
WantedBy=default.target

# chmod 744 /usr/local/bin/wol-omv.sh
# chmod 664 /etc/systemd/system/wol-omv.service

sudo systemctl daemon-reload
# systemctl enable wol-omv.service

Attendre la fin du script

Ceci est un brouillon!

https://unix.stackexchange.com/questions/599372/kill-systemd-oneshot-service-after-timeout
https://trstringer.com/simple-vs-oneshot-systemd-service/
https://docs.fedoraproject.org/en-US/quick-docs/understanding-and-administering-systemd/

Terminal

https://serverfault.com/questions/267099/terminal-only-shows

Webcam

Settings of webcam:

v4l-utils

$ sudo apt-get install v4l-utils

$ v4l2-ctl -l

to list the possible settings

$ v4l2-ctl -c focus_auto=0

to disable the autofocus

$ v4l2-ctl -c focus_absolute=100

to set the focus at value “100”

GTK+ UVC Viewer (UNOFFICIAL)

installed via the software manager (look for “guvcview”)