Accessing package information

Accessing package information
	Managing packages

The package list
Detailed package information

Information about packages is presented in several locations in aptitude: the package list gives a quick overview of the state of each package, and additional views providing detailed information about a package are also available.

The package list

The package list displays an “at-a-glance” synopsis of a package's state. For instance, the package webmin might have the following synopsis:

piAU  webmin                                        +5837kB <none>     1.160-2

The four characters on the left-hand side of the synopsis show that the package is not installed (“p”), that it is going to be installed (“i”), that it was automatically chosen to be installed (“A”), and that it is untrusted (“U”). On the right-hand side of the synopsis, the current version and the most recent available version are displayed, along with an indication of how much space will be used by the upgrade.

	Tip
	You can customize how package synopses are displayed; see the section called “Customizing how packages are displayed” for details.

The four status flags on the left-hand side of the screen give the basic information about a package's state. The first character is the package's current state. The second character is the action which will be taken on the package. The third character indicates whether the package was automatically installed (see the section called “Managing automatically installed packages”), and the fourth character indicates whether the package is trusted (see the section called “Understanding and managing package trust”).

The possible values of the “current state” flag are given in Figure 2.9, “Values of the “current state” flag” and the possible values of the “action” flag are given in Figure 2.10, “Values of the “action” flag”.

Figure 2.9. Values of the “current state” flag

`i`	-	the package is installed and all its dependencies are satisfied.
`c`	-	the package was removed, but its configuration files are still present.
`p`	-	the package and all its configuration files were removed, or the package was never installed.
`v`	-	the package is virtual.
`B`	-	the package has broken dependencies.
`u`	-	the package has been unpacked but not configured.
`C`	-	half-configured: the package's configuration was interrupted.
`H`	-	half-installed: the package's installation was interrupted.
`W`	-	triggers-awaited: the package awaits trigger processing by another package.
`T`	-	triggers-pending: The package has had an update triggered due to changes in another package.

Figure 2.10. Values of the “action” flag

`i`	-	the package will be installed.
`u`	-	the package will be upgraded.
`w`	-	the package will be downgraded.
`d`	-	the package will be deleted: it will be removed, but its configuration files will remain on the system.
`p`	-	the package will be purged: it and its configuration files will be removed.
`h`	-	the package will be held back: it will be kept at its current version, even if a newer version becomes available, until the hold is cancelled.
`F`	-	An upgrade of the package has been forbidden.
`r`	-	the package will be reinstalled.
`B`	-	the package is “broken”: some of its dependencies will not be satisfied. aptitude will not allow you to install, remove, or upgrade anything while you have broken packages.

In addition, aptitude will use colors to indicate package state if your terminal supports it. State distinctions are mainly displayed using the background color:

Black: The package cannot be upgraded (or is not going to be installed), and it has no dependency problems. If the package is installed, its name will be highlighted.
Green: The package is going to be installed.
Blue: The package is currently installed, and it will be upgraded.
Brown: The package is currently installed, and it will be downgraded.
Magenta: The package is currently installed, but it will be removed.
White: The package is currently installed, and it is “held” at its current version: automatic upgrades will ignore it.
Red: This package is broken: some of its dependencies will not be satisfied.

Finally, the lower half of the screen displays the long description. aptitude will attempt to detect whether the package is involved in a dependency problem; if so, information regarding the dependency problem will be displayed here. To cycle between dependency information and the package description, press i.

Detailed package information

Pressing Enter while a package is highlighted will display the package information screen:

[D]

This display can be navigated in a manner similar to the package list: for instance, in the screenshot above, I expanded the dependency on apt-doc, revealing the available versions of apt-doc which will fulfill the dependency. These versions can be manipulated in the same way that packages can: for instance, to install version 0.5.25 of apt-doc, you would highlight it and press +.

	Tip
	To quickly satisfy a dependency, select the dependency and press +; aptitude will attempt to automatically satisfy it.

In addition to the dependencies of a package, you can view the package names that it Provides, the packages which depend upon it, and the available versions of the package (including any other packages that Provide it).

As usual, you can dismiss this screen and return to the main view by pressing q. For convenience, a few other information screens (which only display some commonly-used information, hiding the rest) are available: press v to view the versions of a package, d to view the dependencies of a package, and r to view the “reverse dependencies” of a package (packages which depend upon it).