apt (advanced packaging tool) and its family of programs (apt-get, apt-cache, apt-file) are the default way to manage dependencies on Debian and derived distros (like Ubuntu).
apt keeps a local index of packages, which is what most commands reference.
To update this, run
sudo apt update. If you don’t run that you may be dealing with stale package metadata.
$ sudo apt install hello Reading package lists... Done [...] Setting up hello (2.10-3) ... Processing triggers for man-db (2.11.2-2) ... Processing triggers for install-info (6.8-6+b1) ... $ hello Hello, world!
Note that since apt installs packages system-wide, you must have root permissions to install. If you don’t, you’ll get a permission error like follows:
$ apt install hello E: Could not open lock file /var/lib/dpkg/lock-frontend - open (13: Permission denied) E: Unable to acquire the dpkg frontend lock (/var/lib/dpkg/lock-frontend), are you root?
apt list --installed
$ apt list --installed | head -5 WARNING: apt does not have a stable CLI interface. Use with caution in scripts. Listing... aardvark-dns/stable,now 1.4.0-3 amd64 [installed,automatic] accountsservice/stable,now 22.08.8-6 amd64 [installed,automatic] acl/stable,now 2.3.1-3 amd64 [installed,automatic] adduser/stable,now 3.134 all [installed]
Since I piped the output of this command, it is warning me that the output is subject to change. This is the case for all apt subcommands.
Rather than using apt directly in scripts, you should use its noninteractive versions, like so (this shows manually installed packages, not all packages):
guides $ apt-mark showmanual | head -5 adduser adwaita-icon-theme apt apt-file apt-rdepends
You can always use the web interface for this:
apt-cache search --names-only
$ apt-cache search --names-only openjdk openjdk-17-dbg - Java runtime based on OpenJDK (debugging symbols) openjdk-17-demo - Java runtime based on OpenJDK (demos and examples) [...]
apt-cache search. This is the default behavior.
If you’re doing this for the first time, you’ll have to set up the apt file database.
$ sudo apt install apt-file $ sudo apt-file update
Here’s how the search results look:
$ apt-file search zbarimg zbar-tools: /usr/bin/zbarimg zbar-tools: /usr/share/man/man1/zbarimg.1.gz
apt show. The description field is a human-language description of the package.
$ apt show postgresql Package: postgresql Version: 15+248 Priority: optional Section: database [...] Description: object-relational SQL database (supported version) [...]
$ apt depends znc znc Depends: libboost-locale1.74.0 (>= 1.74.0+ds1) Depends: libc6 (>= 2.34) [...]
apt rdepends --installed
$ apt rdepends --installed libldb2 libldb2 Reverse Depends: Depends: samba-libs (>= 2:2.6.2) Depends: samba-libs (>= 2:2.6.2)
$ apt download znc Get:1 https://deb.debian.org/debian bookworm/main amd64 znc amd64 1.8.2-3.1 [1846 kB] Fetched 1846 kB in 0s (3857 kB/s) $ ls znc_1.8.2-3.1_amd64.deb
Go to a directory you’d like to have the code in, then use
$ apt source vim Reading package lists... Done NOTICE: 'vim' packaging is maintained in the 'Git' version control system at: https://salsa.debian.org/vim-team/vim.git Please use: git clone https://salsa.debian.org/vim-team/vim.git to retrieve the latest (possibly unreleased) updates to the package. [...] dpkg-source: info: applying Fix-GH-267-where-indent-after-a-sub-would-not-work.patch stuff $ ls vim-9.0.1378/ vim_9.0.1378-2.debian.tar.xz vim_9.0.1378-2.dsc vim_9.0.1378.orig.tar.xz
In this example, vim is tracked in git (as are many packages) so there is a helpful hit about how to access the git source repository directly.
Apt can operate on relative file paths like so:
$ sudo apt install ./rtx_2023.9.1_amd64.deb Reading package lists... Done Building dependency tree... Done Reading state information... Done Note, selecting 'rtx' instead of './rtx_2023.9.1_amd64.deb' The following NEW packages will be installed: rtx 0 upgraded, 1 newly installed, 0 to remove and 0 not upgraded. Need to get 0 B/6955 kB of archives. After this operation, 18.8 MB of additional disk space will be used. Get:1 /home/razzi/hack/rtx_2023.9.1_amd64.deb rtx amd64 2023.9.1 [6955 kB] Selecting previously unselected package rtx. [...]
Even though it says “selecting … instead of …”, note that when it fetches the package, the path is a file path, rather than a http url :)
A lot of times you’ll see this done with the underlying debian package manager, dkpg.
To use that tool the command is
sudo dpkg -i.
$ sudo dpkg -i znc_1.8.2-3.1_amd64.deb
sudo apt remove. It will prompt you for whether or not to continue.
$ sudo apt remove docker
It might also tell you about packages that are installed but no longer required - they aren’t removed automatically. As the message says, use
sudo apt autoremove to remove them.
$ sudo apt build-dep vim
Usually this happens when you run
sudo apt update && sudo apt upgrade -y.
But if you just want a single version upgraded to latest,
sudo apt install it again.
$ sudo apt update $ sudo apt install openjdk-17-jdk
$ git clone https://salsa.debian.org/vim-team/vim.git $ cd vim $ sudo apt build-dep vim $ ./configure --enable-python3interp --with-features=huge --enable-fail-if-missing $ make $ sudo make install