Datasheet

94
Part I ✦ The Fundamentals
Since the configuration file you created is fake, press Y and press Enter to use the
packaged version. The installation will complete normally after that.
Upgrading Packages
As mentioned in the introduction of this book, sarge users won’t be getting updates
very often; it’s a stable release and will only occasionally get a security update.
However, when sarge does get an update, it’s more than likely a very important fix.
As such, it’s important to go through the upgrade process at least once daily to
check for upgrades. sid users will likely go through this upgrading process daily
anyway, since sid receives updates on a continual basis.
If you use sid, see http://people.debian.org/~dbharris/tracking-sid/
for some helpful tips on upgrading that are specific to sid. Whether you use sid or
sarge, visit http://people.debian.org/~dbharris/check-updates/ for
details on getting your Debian system to automatically check for updates and e-mail
you when any are available.
Upgrading using apt-get
As usual, before attempting to install or upgrade a package, run apt-get update
to download the latest package lists from the Debian servers. After having done so,
upgrading is as simple as running
apt-get upgrade. apt-get upgrade won’t, by
default, allow any packages to be removed. If there’s a case where a package needs
to be removed, some packages will be held back. This is often the case where a
package has been renamed; the procedure in that case is for
apt-get to remove
the old package and install the new one. This is typically a trouble-free process, per-
formed automatically, but it’s always safer to act conservatively. If you see a pack-
age being held back, you can instead use
apt-get dist-upgrade, which will then
allow
apt-get to satisfy package relationships by removing packages. Carefully
examine the output, however, to make sure that nothing you care about is being
removed— or at least that nothing you care about is being removed without being
replaced.
Configuration File Handling with ucf
The information on configuration file handling in this section refers to regular configuration
files, the kind that are included in the package normally and aren’t generated at install time.
In that simple case,
dpkg itself is displaying the prompt and handling the configuration file.
However, pretty much any package that uses
debconf scripts also creates a default config-
uration file on the fly during the package’s installation. As such, the handling is slightly dif-
ferent.
ucf emulates the standard dpkg prompt in many ways, with the exception that it
uses
debconf for its user interface. The options will be the same, and the reasons are the
same, although the display will look different.
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