dpkg -S string        Display the package(s) providing files with names containing <string>
  rpm -qf filename      (RPM requires filename with absolute path)
dpkg -S name          Display information about package <name>
  rpm -qi name
dpkg -L name          Display all files provided by package <name>
  rpm -ql name
dpkg -l               Display a table of all installaed packages
  rpm -qa
                      Display information about uninstalled package <name>
  rpm -qip name


apt-cache search string Display all packages with names/descriptions containing <string>
apt-cache show name   Display information about package <name>