dpkg(1)

dpkg is the core package management tool for Debian-based systems. It installs, removes, configures, and manages individual .deb packages. Unlike apt or apt-get (which handle dependencies automatically), dpkg works directly with package files and the local package database.

dpkg maintains a database of installed packages in /var/lib/dpkg and tracks their files, versions, and configuration. It can install packages, list what's installed, check package contents, and manage dependencies (though it won't automatically fetch missing dependencies—that's apt's job).

Most users interact with dpkg indirectly through apt, but dpkg is essential for scripting, troubleshooting broken package states, and directly managing .deb files.

Install a .deb file directly

dpkg -i ./package.deb

List all installed packages and filter for nginx

dpkg -l | grep nginx

Show all files installed by the nginx package

dpkg -L nginx

Find which package owns the /usr/bin/curl file

dpkg -S /usr/bin/curl

Remove postgresql package but keep its config files

dpkg -r postgresql

Completely remove postgresql including all config files

dpkg -P postgresql

Show detailed status and version info for the bash package

dpkg -s bash

List all files inside a .deb file without installing

dpkg -c ./package.deb