How do I search for available packages from the command-line?

To search for a particular package by name or description:

From the command-line, use:

apt-cache search keyword

where the search keyword can be all or part of a package name or any words used in its description.

For example, apt-cache search proxy includes both these packages:

tinyproxy - A lightweight, non-caching, optionally anonymizing HTTP proxy
tircd - ircd proxy to the twitter API

Note: the list may be long, so you can pipe the output to less to make it scrollable one line or one screen at a time, i.e. apt-cache search something | less.

To get a list of ALL packages

apt-cache search .

Use Synaptic if you have X-forwarding enabled or are on a desktop

Synaptic is often a more convenient way to do this, but requires at least an X server on your end (unless you're running a desktop environment). Install with sudo apt-get install synaptic if necessary.

• Synaptic on ssh'd server via X forwarding:

  

• Synaptic running locally on Ubuntu Desktop:

  

Using aptitude, apt-cache, and apt all format the output differently. (None of these require the use of sudo when searching for a package.) I prefer using apt for its readability. It highlights the package name and puts a space between the different packages. It also has [installed] listed next to each package that is already installed. Usage:

apt search package-name

You can also use aptitude from the command line:

aptitude search xxxxxx

The apt-cache command line tool is used for searching apt software package cache. In simple words, this tool is used to search software packages, collects information of packages and also used to search for what available packages are ready for installation on Debian or Ubuntu based systems.

To find out the package name and with it description before installing, use the ‘search‘ flag. Using “search” with apt-cache will display a list of matched packages with short description. Let’s say you would like to find out description of package ‘vsftpd‘, then command would be.

Syntax:

apt-cache search SearchTerm

$ apt-cache search vsftpd

The possible output would be:

vsftpd - lightweight, efficient FTP server written for security
ccze - A robust, modular log coloriser
ftpd - File Transfer Protocol (FTP) server
yasat - simple stupid audit tool

To find and list down all the packages starting with ‘vsftpd‘, you could use the following command.

$ apt-cache pkgnames vsftpd

You may also want to run the results through a more, or even a grep. For instance:

apt-cache search firefox | grep plugin

Assuming you want to do all of this from the terminal use the following:

first I recommend you update the package index files so the list of all files in the repository you are about to create is up to date

sudo apt-get update

then use "search regex" function in apt-cache where "regex" stands for Regular Expression and is the pattern given to search. For more info about search patterns you can look up manual regex(7) by command man 7 regex or in English. A regex variable equal to . will suffice.

apt-cache search .

The above will give you ALL the results but it is not in any order that is particularly helpful for browsing.

So finally we can sort by dictionary order usingsort -d and show only a page at a time usingless.

apt-cache search . |sort -d |less

Unfortunately I don't have enough rep to add this a comment on the main answer.

But I was trying to find g++- - alike packages with apt-cache search. It's important to know in this case that keyword is a regular expression so apt-cache search g++- will not have helpful results.

apt-cache search "g[+][+][-]" would be the way to go

apt list <package> is how I recommend searching for packages. If you don't get any matches or if you're not sure what the package is named, try wrapping the argument in asterisks to get more results. For instance apt list *chrome* will yield the following:

Listing...
chrome-gnome-shell/focal,focal,now 10.1-5 all
chromium-chromedriver/focal-updates 1:85.0.4183.83-0ubuntu0.20.04.2 amd64
chromium-lwn4chrome/focal,focal 1.0-3 all
google-chrome-beta/stable 99.0.4844.17-1 amd64
google-chrome-stable/stable,now 98.0.4758.80-1 amd64
google-chrome-unstable/stable 100.0.4867.0-1 amd64
mkchromecast-alsa/focal,focal 0.3.8.1-1 all
mkchromecast-gstreamer/focal,focal 0.3.8.1-1 all
mkchromecast-pulseaudio/focal,focal 0.3.8.1-1 all
mkchromecast/focal,focal 0.3.8.1-1 all
node-chrome-trace-event/focal,focal 1.0.2-1 all
openchrome-tool/focal 1:0.6.0-3build1 amd64
python3-pychromecast/focal,focal 4.1.0-1 all
ruby-chromedriver-helper/focal,focal 2.1.0-7 all
xserver-xorg-video-openchrome-hwe-18.04/focal 3:14.5 amd64
xserver-xorg-video-openchrome/focal 1:0.6.0-3build1 amd64

Alternatively, if you'd like a description of each package, run apt search --names-only <package>. Make sure to include --names-only for more accurate results.

The OP aimed only to apt, which was already answered (apt search). Some people might end up here searching for solutions for other (more modern) alternatives.

Nowadays we have other sources for apps: pip, brew, flatpak and npm, to name a few popular ones. All of them also works with search subcommand.

You could handle all of the above and others with meta-package-manager, which solves XKCD #1654 (don't look #927).

apt-file search part_of_package_name

"Extended variant" is useful in case of excessive number of results:

apt-file search part_of_package_name | grep another_part_of_name

Example of searching for ssh server package if I do not know the name is ssh-server or sshserver or server-ssh etc.:

apt-file search ssh | grep server

Steps to prepare apt-file search for searching. It should be done before first usage:

sudo apt-get install apt-file
sudo apt-file update