Category: Ubuntu

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Cups Printer Management from Command Line

Refer: https://www-uxsup.csx.cam.ac.uk/pub/doc/suse/suse9.1/adminguide9.1/ch05s07.html

Sample Commands

Help

lpstat --help

General Status

lpstat -t

List of Printers

lstat -v

5.7.3.Using Command-Line Tools for CUPS Troubleshooting

Print jobs will be kept in the printer queue if you shut down the system while a job is being processed. This means a broken print job will still be there even after rebooting and you need to remove it from the queue manually with the commands mentioned above.

Other problems occur if there is some fault in the physical data link between the computer and the printer. The printer may then be unable to make sense of the data it receives and start spitting out lots of pages with garbage on them.

To make sure the printer stops working, first remove all paper from it (in the case of inkjet printers) or open the paper trays (laser printers).

At this point, the print job will often still be in the queue, because jobs are only removed from the queue when all data has been sent to the device. Check which queue is currently printing by entering 

lpstat -o

Then remove the problematic print job wit

cancel queuename-jobnumber

Some data might still find their way to the printer in spite of the job having been deleted. To stop this, enter the command fuser -k /dev/lp0 (for a printer at the parallel port) or fuser -k /dev/usb/lp0 (for a USB printer). This kills any processes still using the printer device.

Do a complete reset of the printer by disconnecting it from power for some time. Then put in the paper and switch the printer back on.

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diceware – To generate passwords

Refer: http://manpages.ubuntu.com/manpages/bionic/man1/diceware.1.html

Sample Usage
Four words, and separate by dash

$ diceware -n 4 -d -

Installation
$ sudo apt-get update -y
$ sudo apt-get install -y diceware

 

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Install gTile and/or Gnome Extensions

Installing Gnome Extensions - Wanted for gTile

Usage Refer: https://github.com/gTile/gTile

Refer: https://linuxconfig.org/how-to-install-gnome-shell-extensions-on-ubuntu-20-04-focal-fossa-linux-desktop

$ sudo apt install gnome-shell-extensions
Logoff and Logon Again
Install Firefox extension: https://extensions.gnome.org/
Click on the gnome extension icond in Firefox
Search for gTile and install it

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Allow MP4 to Play in Ubuntu 20.04

Refer: https://linuxconfig.org/unable-to-play-the-file-missing-decoder-on-ubuntu-20-04-lts-focal-fossa

Error Message when trying to play MP4:
Video mp4 dvd subpicture decoder is required to play the file but is not installed

sudo apt install -y vlc
sudo apt install ubuntu-restricted-extras
sudo apt install libdvdnav4 libdvd-pkg gstreamer1.0-plugins-bad gstreamer1.0-plugins-ugly
sudo reboot

Older notes: Don't think these fixed anything; however, you do need to install VLC standard

Refer: https://itsfoss.com/play-dvd-ubuntu-1310/

These commands don't really do the trick:

sudo add-apt-repository multiverse
sudo apt install -y libdvd-pkg
sudo dpkg-reconfigure libdvd-pkg

Important: You need to install VLC from command line and NOT Snap version

sudo apt install -y vlc

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Ubuntu update error “waiting for unattended-upgr to exit”

Refer: https://techtips.easycloudsolutions.com/2018/05/15/ubuntu-update-error-waiting-for-unattended-upgr-to-exit/

Stop the automatic updater.

$ sudo dpkg-reconfigure -plow unattended-upgrades

At the first prompt, choose not to download and install updates.

Make a reboot. Make sure any packages in an unclean state are installed correctly.

$ sudo dpkg --configure -a

Get your system up-top-date.

$ sudo apt update && sudo apt -f install && sudo apt full-upgrade

Turn the automatic updater back on, now that the blockage is cleared.

$ sudo dpkg-reconfigure -plow unattended-upgrades

Select the package unattended-upgrades again.

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MenuLibre Fails to Launch

Refer: https://askubuntu.com/questions/450382/xubuntu-menulibre-application-menu-editor-not-launching

Fix as follows, because of corrupted menus

mv ~/.config/menus/ ~/.config/menus.bak