APT also known as Advanced Packaging Tool is the command-line tool for managing packages in Debian-based distributions like Ubuntu 16.04, Ubuntu 18.04, Debian 8, Debian 9 and much more. APT simplifies the process of installing, removing, upgrading packages and even used to upgrade the entire operating system through the Command Line Interface
In this tutorial, we will explain how to manage packages using APT command line tool on Ubuntu 18.04 LTS server.
Requirements
A server running Ubuntu 18.04 LTS.
A root or sudo access on the server.
All commands below are run as root user. Either log in as root user on the shell or run:
sudo -s
to become the root user. As an alternative, you can prepend 'sudo ' to all commands.
Install and Update Packages
Apt-get works by obtaining information from different sources and stored in a local database. The update command fetched the packages from their locations and update the packages to a newer version.
apt-get update -y
After running the above command, your database should be up-to-date.
The upgrade command is used to upgrade all the currently installed software packages to the newer version.
apt-get upgrade -y
You can also use dist-upgrade command to upgrade the packages, but it changes package dependencies with a smart conflict resolution method.
apt-get dist-upgrade -y
Once your database is updated, you can install any packages by running the following command:
apt-get install package1 package2
For example, you can install Nginx web server package by running the following command:
apt-get install nginx
If you want to download only package file but not install it, you can run the following command:
apt-get install -d package1
The above command will download the package file in /var/cache/apt/archives directory.
To reinstall any package with the newer version run the following command:
apt-get install package1 --reinstall
Remove a Package with Apt
To remove a package from your system simply run the following command:
apt-get remove package1
The above command will only remove the package but keep the configuration file.
To remove the package with configuration file with the following command:
apt-get purge package1
You can also remove all unwanted packages and clean the database with the following command:
apt-get autoremove apt-get clean
Search Package with Apt-Cache
The command apt-cache is used to search for software packages.
To find the package by its description, run the following command:
apt-cache search proftpd
You should see the following output:
resource-agents - Cluster Resource Agents fail2ban - ban hosts that cause multiple authentication errors ftpd - File Transfer Protocol (FTP) server gadmin-proftpd - GTK+ configuration tool for proftpd gadmin-proftpd-dbg - GTK+ configuration tool for proftpd debug package gadmintools - GTK+ server administration tools (meta-package) proftpd-basic - Versatile, virtual-hosting FTP daemon - binaries proftpd-dev - Versatile, virtual-hosting FTP daemon - development files proftpd-doc - Versatile, virtual-hosting FTP daemon - documentation proftpd-mod-autohost - ProFTPD module mod_autohost proftpd-mod-case - ProFTPD module mod_case proftpd-mod-clamav - ProFTPD module mod_clamav proftpd-mod-dnsbl - ProFTPD module mod_dnsbl proftpd-mod-fsync - ProFTPD module mod_fsync proftpd-mod-geoip - Versatile, virtual-hosting FTP daemon - GeoIP module proftpd-mod-ldap - Versatile, virtual-hosting FTP daemon - LDAP module proftpd-mod-msg - ProFTPD module mod_msg proftpd-mod-mysql - Versatile, virtual-hosting FTP daemon - MySQL module proftpd-mod-odbc - Versatile, virtual-hosting FTP daemon - ODBC module proftpd-mod-pgsql - Versatile, virtual-hosting FTP daemon - PostgreSQL module proftpd-mod-sqlite - Versatile, virtual-hosting FTP daemon - SQLite3 module proftpd-mod-tar - ProFTPD module mod_tar proftpd-mod-vroot - ProFTPD module mod_vroot
To find all the packages starting with proftpd with the following command:
apt-cache pkgnames proftpd
You should see the following output:
apt-cache pkgnames proftpd proftpd-mod-dnsbl proftpd-mod-odbc proftpd-mod-pgsql proftpd-doc proftpd-mod-tar proftpd-mod-ldap proftpd-mod-case proftpd-mod-geoip proftpd-mod-mysql proftpd-basic proftpd-mod-vroot proftpd-mod-clamav proftpd-mod-autohost proftpd-mod-fsync proftpd-mod-sqlite proftpd-mod-msg proftpd-dev
You can check the complete information of any package (nano) with the following command:
apt-cache show nano
Output:
Package: nano Priority: standard Section: editors Installed-Size: 600 Maintainer: Ubuntu Developers <ubuntu-devel-discuss@lists.ubuntu.com> Original-Maintainer: Jordi Mallach <jordi@debian.org> Architecture: amd64 Version: 2.2.6-1ubuntu1 Replaces: pico Provides: editor Depends: libc6 (>= 2.14), libncursesw5 (>= 5.6+20070908), libtinfo5, dpkg (>= 1.15.4) | install-info Suggests: spell Conflicts: pico Breaks: alpine-pico (<= 2.00+dfsg-5) Filename: pool/main/n/nano/nano_2.2.6-1ubuntu1_amd64.deb Size: 194060 MD5sum: c97dc062e9941bfe13b6b303cf8ed639 SHA1: ee93fcfd1f2ecd601b0a8f8932319848043f4f0f SHA256: f20d8cca5c30b90ebf68301d126f86e473ac83e7d6fdc36f59bcd685c2eb4020 Description-en: small, friendly text editor inspired by Pico GNU nano is an easy-to-use text editor originally designed as a replacement for Pico, the ncurses-based editor from the non-free mailer package Pine (itself now available under the Apache License as Alpine). . However, nano also implements many features missing in pico, including: - feature toggles; - interactive search and replace (with regular expression support); - go to line (and column) command; - auto-indentation and color syntax-highlighting; - filename tab-completion and support for multiple buffers; - full internationalization support. Description-md5: b7e1d8c3d831118724cfe8ea3996b595 Homepage: http://www.nano-editor.org/ Bugs: https://bugs.launchpad.net/ubuntu/+filebug Origin: Ubuntu Supported: 5y Task: standard, kubuntu-active, kubuntu-active
To check the dependencies of a specific package with the following command:
apt-cache showpkg htop
Output:
Package: htop
Versions:
2.1.0-3 (/var/lib/apt/lists/archive.ubuntu.com_ubuntu_dists_bionic_main_binary-amd64_Packages) (/var/lib/dpkg/status)
Description Language:
File: /var/lib/apt/lists/archive.ubuntu.com_ubuntu_dists_bionic_main_binary-amd64_Packages
MD5: 8eb5aa19b3c92a975dc78e2165f6688d
Description Language: en
File: /var/lib/apt/lists/archive.ubuntu.com_ubuntu_dists_bionic_main_i18n_Translation-en
MD5: 8eb5aa19b3c92a975dc78e2165f6688d
Reverse Depends:
ubuntu-server,htop
lubuntu-qt-desktop,htop
lubuntu-gtk-desktop,htop
lubuntu-desktop,htop
util-vserver,htop
ubuntu-benchmark-tools,htop
lubuntu-qt-desktop,htop
lubuntu-gtk-desktop,htop
lubuntu-desktop,htop
hollywood,htop
freedombox-setup,htop
Dependencies:
2.1.0-3 - libc6 (2 2.15) libncursesw5 (2 6) libtinfo5 (2 6) lsof (0 (null)) strace (0 (null))
Provides:
2.1.0-3 -
Reverse Provides:
To check whether a package is installed or not and which repository it belongs to with the following command:
apt-cache policy apache2
You should see the following output:
apache2:
Installed: 2.4.29-1ubuntu4.5
Candidate: 2.4.29-1ubuntu4.5
Version table:
*** 2.4.29-1ubuntu4.5 500
500 http://archive.ubuntu.com/ubuntu bionic-updates/main amd64 Packages
100 /var/lib/dpkg/status
2.4.29-1ubuntu4.4 500
500 http://security.ubuntu.com/ubuntu bionic-security/main amd64 Packages
2.4.29-1ubuntu4 500
500 http://archive.ubuntu.com/ubuntu bionic/main amd64 Packages
APT Advanced Usage
You can also check for broken dependencies with the following command.
apt-get check
You should see the following output:
Reading package lists... Done Building dependency tree Reading state information... Done
To search and install the build dependencies for a package (here vsftpd), use the following command:
apt-get build-dep vsftpd
You should see all the dependencies required by vsftpd package in the following output:
Reading package lists... Done Building dependency tree Reading state information... Done Note, selecting 'libcap-dev' instead of 'libcap2-dev' The following NEW packages will be installed: debhelper dh-apparmor dh-apport libcap-dev libpam0g-dev po-debconf The following packages will be upgraded: libpam0g 1 upgraded, 6 newly installed, 0 to remove and 595 not upgraded. 1 not fully installed or removed. Need to get 1,020 kB of archives. After this operation, 2,238 kB of additional disk space will be used. Do you want to continue? [Y/n]
To download the source code of any package, unpack and compile a package by running the following command:
apt-get --compile source htop
You should see the following output:
Reading package lists... Done NOTICE: 'htop' packaging is maintained in the 'Git' version control system at: https://salsa.debian.org/debian/htop.git Please use: git clone https://salsa.debian.org/debian/htop.git to retrieve the latest (possibly unreleased) updates to the package. Need to get 314 kB of source archives. Get:1 http://archive.ubuntu.com/ubuntu bionic/main htop 2.1.0-3 (dsc) [1,961 B] Get:2 http://archive.ubuntu.com/ubuntu bionic/main htop 2.1.0-3 (tar) [303 kB] Get:3 http://archive.ubuntu.com/ubuntu bionic/main htop 2.1.0-3 (diff) [8,824 B] Fetched 314 kB in 35s (8,877 B/s) dpkg-source: info: extracting htop in htop-2.1.0 dpkg-source: info: unpacking htop_2.1.0.orig.tar.gz dpkg-source: info: unpacking htop_2.1.0-3.debian.tar.xz dpkg-source: info: applying 601-openvz-new-ctid-vpid.patch dpkg-source: info: applying fix-small-terminals.patch dpkg-source: info: applying fix-ldflags.patch dpkg-source: info: applying fix-isalnum-crash.patch dpkg-buildpackage: info: source package htop dpkg-buildpackage: info: source version 2.1.0-3 dpkg-buildpackage: info: source distribution unstable dpkg-buildpackage: info: source changed by Graham Inggs <ginggs@debian.org> dpkg-buildpackage: info: host architecture amd64
To check the version of APT with the following command:
apt-get -v
Output:
apt 1.6.1 (amd64) Supported modules: *Ver: Standard .deb *Pkg: Debian dpkg interface (Priority 30) Pkg: Debian APT solver interface (Priority -1000) Pkg: Debian APT planner interface (Priority -1000) S.L: 'deb' Debian binary tree S.L: 'deb-src' Debian source tree Idx: Debian Source Index Idx: Debian Package Index Idx: Debian Translation Index Idx: Debian dpkg status file Idx: Debian deb file Idx: Debian dsc file Idx: Debian control file Idx: EDSP scenario file Idx: EIPP scenario file
You can list all the available options with APT by running the following command:
apt-get -h
Output:
apt 1.6.1 (amd64)
Usage: apt-get [options] command
apt-get [options] install|remove pkg1 [pkg2 ...]
apt-get [options] source pkg1 [pkg2 ...]
apt-get is a command line interface for retrieval of packages
and information about them from authenticated sources and
for installation, upgrade and removal of packages together
with their dependencies.
Most used commands:
update - Retrieve new lists of packages
upgrade - Perform an upgrade
install - Install new packages (pkg is libc6 not libc6.deb)
remove - Remove packages
purge - Remove packages and config files
autoremove - Remove automatically all unused packages
dist-upgrade - Distribution upgrade, see apt-get(8)
dselect-upgrade - Follow dselect selections
build-dep - Configure build-dependencies for source packages
clean - Erase downloaded archive files
autoclean - Erase old downloaded archive files
check - Verify that there are no broken dependencies
source - Download source archives
download - Download the binary package into the current directory
changelog - Download and display the changelog for the given package
See apt-get(8) for more information about the available commands.
Configuration options and syntax is detailed in apt.conf(5).
Information about how to configure sources can be found in sources.list(5).
Package and version choices can be expressed via apt_preferences(5).
Security details are available in apt-secure(8).
This APT has Super Cow Powers.
That's all
