Linux: Software Configuration and Management

Basics

• Debian-based systems use apt
• RHEL-based systems use yum and dnf
• openSUSE systems use Zypper

Package Managers

We use package managers to search, install, configure, update, and remove software in Linux environments.

apt - Debian-based systems

• apt update to update all package list
• apt upgrade to update all packages
• apt install <PACKAGE> to install a package
• apt remove <PACKAGE> to remove a package
• apt show <PACKAGE> to show package details
• apt search <PACKAGE> to search for a package
• apt purge <PACKAGE> to delete a package and associated file
• apt list --installed to show all installed packages
• apt clean to clear cached downloaded packages
• apt full-upgrade to the system distribution
• apt depends <PACKAGE> to show package dependencies
• apt rdepends <PACKAGE> to show packages that depend on the selected package
• apt-mark hold <PACKAGE> to lock a package at its current version
• apt-mark unhold <PACKAGE> to unhold a currently held package
• apt-mark showhold to show packages currently on hold

dnf - REHL-based systems

• dnf check-update to update all package list
• dnf upgrade to update all packages
• dnf install <PACKAGE> to install a package
• dnf remove <PACKAGE> to remove a package
• dnf search <PACKAGE> to search for a package
• dnf list installed to view all installed packages
• dnf clean all to clear cached packages
• dnf history to show transaction history
• dnf repolist to list enabled repositories
• dnf versionlock list to list all locked packages
• dnf versionlock clear to clear all locked packages
• dnf versionlock add <PACKAGE> to lock a package at its current version
• dnf versionlock delete <PACKAGE> to delete a "version locked" package
• dnf config-manager --set-enabled <REPO NAME> to enable a repository
• dnf config-manager --set-disabled <REPO NAME> to disable a repository

pacman - Arch-based systems

• pacman -Sy to update all package list
• pacman -Su to update all packages
• pacman -S <PACKAGE> to install a package
• pacman -R <PACKAGE> to remove a package
• pacman -Ss <PACKAGE> to search for a package
• pacman -Qi <PACKAGE> to view a package details
• pacman -Q to list all installed packages
• pacman -Sc to clear cached packages

zypper - openSUSE-based systems

• zypper refresh or zypper ref to update all package list
• zypper upgrade or zypper up to update all packages
• zypper upgrade <PACKAGE to update a single package
• zypper info <PACKAGE to view package details
• zypper install <PACKAGE> or zypper in <PACKAGE> to install a package
• zypper remove <PACKAGE> or zypper rm <PACKAGE> to remove a package
• zypper search <PACKAGE> or zypper se <PACKAGE> to search for a package
• zypper patch-check to check for important patches
• zypper al <PACKAGE> (add lock) locks a package to prevent it from being updated or removed during system updates
• zypper rl <PACKAGE> (remove lock) removes a lock
• zypper mr -d (modify repository) to disable a repository

Source Installation

It is a method used to install software when it is not available in repositories or when it requires a custom build.

Installing a software from source usually includes the following steps:

• ./configure to configure the system
• make to build the software
• make install to install the newly built software
• make clean to remove temporary build files

GNU GPG Signatures

GNU GNU Not Unix. Used to verify the authenticity of software packages, and files

GPG GNU Privacy Guard - is used to encrypt and sign data.

GPG usage

gpg --import <KEY FILE> to import a public key. ex: gpg --import developer_public_key.asc

gpg --verify <SIGNATURE FILE> <PACKAGE> to verify a signed package. ex: gpg --verify my_program.tar.gz.sig my_program.tar.gz

gpg --list-keys to list all trusted keys