7 aptitude search mysql # Look for something
8 dpkg -S `which tsclient` # What package does it belong to?
9 dpkg -L aria2c # What does this package provide?
10 dpkg -i *.deb # Install a deb file
11 dpkg -s nodejs # Show info
13 dpkg --get-selections # list installed packages
17 /var/cache/apt/archives