aptitude : the package manager
[SYNOPSIS] aptitude OPTION COMMAND PKG
(If no command is specified, start in interactive mode)
COMMAND
install Install package
remove Uninstall package
purge Delete packages and configuration files
search Search for packages by name or regular expression
show Show detailed information about the package
update Download the list of new and updateable packages
safe-upgrade Make safe updates
full-upgrade Perform updates that may involve installing or removing packages
download Download .deb file for package
reinstall Download and (possibly) reinstall currently installed packages
clean Delete downloaded package files
forget-new Clear information about which packages are "new"
hold Fix the package version
unhold Unpin the fixed package
markauto Mark a package as automatically installed
unmarkauto Mark a package as manually installed
forbid-version Prevent updates to specific package versions
why Displays a description of the specified package, including which manually installed packages require it, or why it is required when a package is installed that is not already installed
why-not Displays a description of the specified package, including which manually installed packages it conflicts with, or why it conflicts when a package is installed that is not already installed.
changelog View package change history

OPTION
-y Say 'yes' to all questions
-s Only simulate actions, do not actually execute them
-d Only downloads packages, do not install or remove them
-v Display additional information
-q Do not display progress in command line mode
-h Show help
-V Show which version of a package is installed
-P Always prompt for confirmation or action
-f Attempt to correct a system with broken dependencies in place
-D Show automatically changed package dependencies
-Z Show installation size changes for each package
-u Show updated packages
-i Install at startup