Java Design Concepts

Ubuntu contains several utilities and applications for managing the software packages. These utilities range from command-line utilities to that with graphical user interfaces that assist the user to easily locate and and install the packages on the system.

Package Management Utilities

Ubuntu contains a range of utilities to install software packages that is located in repositories on the web. These utilities use different databases to store information about the software packages that is installed and removed from the system. The following list contains a few of these utilities:

• dpkg - The dpkg command is the basic utility of Ubuntu for installing, removing and updating software packages.
• apt-get - Apt-get is the command-line tool for handling software packages, and is considered the "back-end" to other tools using the APT library. Front-end interfaces such as aptitude, synaptic and gnome-apt.
• aptitude - Aptitude is terminal-oriented/text-based utility for handling software packages. It allows the user to install, remove and upgrade packages. The aptitude utility makes use of apt-get and dpkg utilities.
• synaptic - The Synaptic front-end application makes use of the apt utility for managing software packages.
• update-manager - Update-manager is a front-end for the apt package management system. It allows you to perform some actions of the command line tool apt-get in a graphical environment. Update-manager is especially designed for upgrading your system, or migrating your system towards a more recent version.

Note: It is important to always execute the update option on the apt-get, dpkg, aptitude and synaptic commands to ensure that the package state is up-to-date.

---

Utility: dpkg

The dpkg command-line utility is the basic, low-level utility for the Debian/Ubuntu Software Package Management system. The utility is used to build, install, remove and manage the Debian (.deb) packages. Higher level tools such as APT is used to retrieve the Debian packages from remote repositories. The dpkg utility stores it's software package information in the /var/lib/dpkg directory. The following is a short list of commands that can be used:

• Install - To install a Debian package the following command can be used: dpkg -i debianPackage; where debianPackage is the name of the package you want to install.
• List - List all the Debian packages that is installed through the package manager with a the pattern: dpkg -l [optional pattern]; the optional pattern can be a pattern that matches any of the installed packages.
• Remove - The following command removes a package that is installed in the package manager: dpkg -r package_name; the package_name is the name of a package that is currently installed.

---

Utility: Apt-Get

The apt-get command-line utility is used to install, manage and remove software packages on the Ubuntu operating system. The sources of the repositories is listed in /etc/apt/sources.list. The utility stores it's software package information in the /var/lib/apt directory. The following options are available for the command-line utility:

• update - The update option is used to resynchronize the package index files from their sources. An update should always be performed before an upgrade or dist-upgrade command is executed.
• upgrade - The upgrade option is used to install the latest version of all the packages installed on the system through the package management tool apt-get.
• install - The install option is used to install the software packages that is listed after install option. All packages that contains dependent packages will be retrieved and installed by the utility.
• remote - The remove option is very similar to that of install except that the packages listed after the remove option is uninstalled.

---

Utility: aptitude

The aptitude utility is a high-level interface used to manage, install and update software packages in Ubuntu. The utility makes use of the APT utility and actions may be performed from an "interactive mode" or from the command-line. The utility stores it's software package information in the /var/lib/aptitude directory. The following are a few of the commands available for the aptitude tool:

• aptitude - Running the command-line without any additional options brings up an interface used to install, update, manage and remove software packages.
• aptitude install - The command followed by one or more packages is used to install the packages and their dependencies.
• aptitude remove - The command removes the packages listed and all the dependent packages not in used any more.
• aptitude search - The command searches for packages matching one of the patterns supplied on the command line.
• aptitude update - The command updates the list of available packages from the apt sources.
• aptitude full-upgrade - The command upgrades installed packages to their most recent version, removing or installing packages as necessary.

---

Utility: synaptic

The Synaptic tool is a front-end for the apt package management system. It allows you to perform all actions of the command line tool apt-get in a graphical environment. The utility stores it's software package information in the /var/lib/synaptic directory.

---

Utility: update-manager

The utility stores it's software package information in the /var/lib/update-manager directory. There are different ways of launching the update-manager utility. The first is to launch the application from the menu within the xserver (System --> Administration --> Update Manager). The second is to launch the application from command-line.

Code:

---

Conclusion

Ubuntu has a lot of package management utilities and tools, both command-line and with graphical interfaces. Depending on the specific task at hand, there is more than one way to get the required software package installed and update in Ubuntu. From low-level command-line tools all the way to high-level graphical applications.