Packages, dependencies and repositories

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Step 8 of 8 · summary · 2 min

Summary

A package comes as a .deb archive: the program's files plus a description with the version, architecture and dependencies.
dpkg -I and dpkg -c read an archive before installation, dpkg -s the record of an installed package.
A dependency is met when the required package is installed; an archive next to it does not count.
Indexes list the packages in the repositories: apt update refreshes them, apt-cache policy compares the installed version with the candidate.
At the start of the lesson the command was not found: /srv/package-lab held archives, and nobody had installed the package.

Ubuntu 24.04