Finding Software: search and info

This machine's repository

A package manager installs from the repositories listed in its configuration. On a normal machine these point at servers on the internet; this browser machine has no network, so it uses a small local copy baked into the image. Everything in this module works offline against it:

cat /etc/apk/repositories

In the terminal

student@vulntech:~$ cat /etc/apk/repositories
# This machine has no internet connection. Instead of the online Alpine
# repositories (https://dl-cdn.alpinelinux.org/alpine/v3.21/main), it
# installs packages from a small local copy:
/srv/packages/main

apk update refreshes the manager's list of what's available. Run it once before searching or installing:

apk update

In the terminal

student@vulntech:~$ apk update
ERROR: Unable to lock database: Permission denied
ERROR: Failed to open apk database: Permission denied

Searching

apk search finds packages whose name matches a word. Add -v to see a one-line description of each match:

apk search jq
apk search -v htop

In the terminal

student@vulntech:~$ apk search jq
jq-1.7.1-r0
jq-doc-1.7.1-r0
student@vulntech:~$ apk search -v htop
htop-3.3.0-r0 - Interactive process viewer
htop-doc-3.3.0-r0 - Interactive process viewer (documentation)

Reading about a package

apk info NAME describes a package: what it's for, its homepage and its size. This works whether or not the package is installed, because it reads the repository's catalogue. -d shows just the description:

apk info htop
apk info -d jq

In the terminal

student@vulntech:~$ apk info htop
htop-3.3.0-r0 description:
Interactive process viewer

htop-3.3.0-r0 webpage:
https://htop.dev/

htop-3.3.0-r0 installed size:
272 KiB
student@vulntech:~$ apk info -d jq
jq-1.7.1-r0 description:
A lightweight and flexible command-line JSON processor

What does it depend on?

-R (requires) lists a package's dependencies, the other packages it needs. jq needs a library for working with text patterns, for example:

apk info -R jq

In the terminal

student@vulntech:~$ apk info -R jq
jq-1.7.1-r0 depends on:
so:libc.musl-x86.so.1
so:libonig.so.5

Tip: One thing is different from Ubuntu's apt show: apk info -L, which lists the files a package installs, only works once the package is installed. You'll use it in the next lessons.

Remember: apk update refreshes the list. apk search word finds packages, apk info NAME describes one, -d its description, -R its dependencies.