====== APT tricks for forgetful debian/ubuntu users ======

To update your package list
  apt-get update

To simulate what would happen if you upgrade/install a package with //--dry-run// or //-s//
  apt-get install --dry-run <pkgname>

To download only a package without installing it with //--download-only// or //-d//
  apt-get install --download-only <pkgname>

Re-install a package that is already installed and at the newest version
  apt-get install --reinstall <pkgname>

To upgrade a single package, and only if it is installed.
  apt-get install --only-upgrade <pkgname>

To do keyword-based package searches 
  apt-cache search <keyword>
  
To display the description, the headers, the dependencies of a package:
  apt-cache show <pkgname>

To show the priority selection of the package (the installed and the repo versions)
  apt-cache policy <pkgname>

To show all the installed files of a package use
  dpkg-query -L <pkgname>
or
  dpkg --listfiles <pkgname>