Using Synaptic for Software Management
The Add/Remove Applications dialog works just fine for adding applications, but if you need to install something specific—such as a library—or if you want to reconfigure your installation system, you need to use Synaptic (Figure 9.2). You can install Synaptic using the Ubuntu Software Center described earlier; it is not installed by default.
FIGURE 9.2 For more advanced software management in a GUI, Synaptic is the preferred tool.
At first glance, Synaptic looks a little like the Add/Remove Applications window. Along the left are software categories (although this time there are more of them), along the top right are the package selections for that category, and on the bottom right is the Package Information window that shows information about the currently selected package. To install or remove software, click the check box to the left of its name, and you’ll see a menu that offers the following options:
- Unmark—If you have marked this package for installation, upgrade, or one of the other options, this option removes that mark.
- Mark for Installation—Add this package to the list that will be installed.
- Mark for Re-installation—If you have some software already installed, but for some reason it’s not working, this option reinstalls it from scratch.
- Mark for Upgrade—If the software has updates available, this option downloads and installs them.
- Mark for Removal—This option deletes the selected package from your system but leaves its configuration files intact so that if you ever reinstall it you do not have to reconfigure it.
- Mark for Complete Removal—This option deletes the selected package from your system but also removes any configuration files, purging everything from the system.
After you have made your changes, click the Apply button to have Synaptic download, install, upgrade, and uninstall as necessary. If you close the program without clicking Apply, your changes are lost.
Beneath the categories on the left side of the screen, you see four buttons: Sections, Status, Search, and Custom, with Sections selected. These customize the left list: Sections is the Categories view; Status enables you to view packages that are installed or upgradable; Search stores results of your searches; and Custom has some esoteric groupings that are useful only to advanced users.
You can press Ctrl+F at any time to search for a particular package. By default it is set to search by package name. You may change the Look In box setting to Description and Name. As mentioned already, your search terms are saved under the Search view (the button on the bottom left), and you can click from that list to re-search on that term.
As well as providing the method of installing and removing software, Synaptic provides the means to configure the servers you want to use for finding packages. In fact, this is where you can make one of the most important changes to your Ubuntu system: You can open it up to the Ubuntu Universe and Multiverse.
Ubuntu is based on the Debian distribution, which has more than 15,000 software packages available for installation. Ubuntu uses only a small subset of that number but makes it easy for you to enable the others. When you use Synaptic, you see small orange Ubuntu logos next to every package; this identifies them as being officially supported by the Canonical-supported Ubuntu developers. The other packages do not have this logo, but they are still supported by the wider Ubuntu community of developers.
To enable the Universe and Multiverse repositories, go to Settings, Repositories. This list shows all the servers you have configured for software installation and updates and includes the Universe and Multiverse repositories. When you find them, check them, and then click Close.
Synaptic shows a message box warning you that the repository listings have changed and that you need to click the Reload button (near the top left of the Synaptic window) to have it refresh the package lists. Go ahead and do that, and you should see a lot more software appear for your selection. However, notice that only a small number have the official Ubuntu “seal” attached, which means you need to be a bit more careful when installing software.