Apt

APT package management, repositories, and maintenance tasks.

APT repository metadata passing through signing key verification

Sep 21, 2026 • 8 min read

Fix the NO_PUBKEY GPG Error on apt update

Fix the apt NO_PUBKEY error on Ubuntu and Debian by installing a verified repository signing key under /etc/apt/keyrings and using signed-by.

APT and dpkg package operations waiting at a shared package lock

Sep 9, 2026 • 8 min read

How to Fix APT and dpkg Lock Errors on Ubuntu and Debian

Resolve APT and dpkg lock errors safely on Ubuntu and Debian by finding the process holding the lock and repairing interrupted package operations.

List Installed Packages with apt and dpkg on Debian

Sep 1, 2026 • 9 min read

How to List Installed Packages on Debian with apt and dpkg

See what is installed on Debian, which packages you chose yourself, which use the most disk space, and when each one arrived, using apt and dpkg-query.

Aug 26, 2026 • 11 min read

How to Add APT Repository in Ubuntu

Add APT repositories in Ubuntu using add-apt-repository, the signed-by method, and PPA. Includes the DEB822 format used by default on Ubuntu 24.04 and 26.04.

Adding an APT repository on Ubuntu using add-apt-repository

Aug 4, 2026 • 6 min read

Install deb Files on Ubuntu: apt, dpkg, and gdebi

Install local .deb files on Ubuntu with apt, dpkg, or gdebi. Fix dependency errors, inspect packages, install via GUI, and remove them safely.

Jul 31, 2026 • 10 min read

apt Command in Linux

The apt command manages packages on Ubuntu, Debian, and related distributions. This guide covers the essential commands for installing, upgrading, removing, and searching packages.

Jul 10, 2026 • 6 min read

apt vs apt-get: The Difference and When to Use Each

apt and apt-get are not the same tool: apt is built for interactive terminal use, apt-get for scripts and automation. Compare their commands and see when to use each.

Apr 21, 2026 • 3 min read

How to Uninstall Software Packages on Ubuntu

How to uninstall software packages on Ubuntu using the apt command or Ubuntu Software. Covers remove, purge, autoremove, and snap package removal.

Apr 14, 2026 • 5 min read

How to List Installed Packages on Ubuntu

List, filter, and export installed packages on Ubuntu with apt and dpkg, including how to find package details, manually installed packages, and install history.

List Installed Packages with apt and dpkg on Ubuntu

May 25, 2020 • 4 min read

How to Set up Automatic Updates on Ubuntu 18.04

Regularly updating your Ubuntu system is one of the most important aspects of overall system security. In this tutorial, we will walk through how to install and configure automatic unattended updates on Ubuntu 18.04.

Enable and Set up Automatic Unattended Security Updates on Ubuntu 18.04