Contents of a debian file

To get the contents of the file "abc.deb", you have to enter

$ dpkg-deb -c abc.deb

Reconfiguring of debconf

To reconfigure debconf, so that it informs you of most changes of the new packages, you have to enter

# dpkg-reconfigure debconf

Chose "medium" here

Package Management with apt-get and dpkg

Package resource list for APT

The file /etc/apt/sources.list is the definition file of the sources for apt. For further information about this file type man 5 sources.list

Retrieve new lists of packages:

To fetch the new lists of all the packages from sources.list enter as ?RootUser

# apt-get update

This command checks for new release-files on the given servers. Luckily the command is clever enough to check if the release-file has changed after the last update.

Upgrade of all the files:

To make an update of all the changed packages, enter the line

# apt-get update -u

The additional flag -u shows a list of upgraded packages as well. If you want to run the update in a cron-job, you should use the flags -dy. With this flags the new packages will be downloaded but not installed. You can install them later by writing apt-get update -u.

Distribution Upgrade of all the files:

To make an upgrade of your actual distribution (e.g from potato to woody or when using unstable) replace upgrade with dist-upgrade when entering your command. So you have to type

apt-get dist-upgrade -dy

apt-get dist-upgrade -u

for an distribution upgrade.

Add a package:

How can you add a package to your system without the gui-programms? All you have to do is find out the name of this package and enter the command

apt-get install sylpheed-claws

to add the package sylpheed-claws.

Remove a package:

To get rid of the package foo which is no longer needed, enter the command

# apt-get remove foo

If the package is needed by other packages you will be prompted to remove this package and all packages which depend on it.

Forced removing of a package:

While making an distibution upgrade it coud happen that you have to remove a package first. But sometimes this is not possible with apt-get remove since the package has unmet dependencies or is not installed completely. You can remove the package foo by using the command

dpkg --force-all --remove foo

Read the contents of a installed package:

Sometimes you wan't to know which files are in the package foo. To get this information enter the command

dpkg -L foo

Get the description of a package:

You don't know what the package foo is for? Just write

dpkg -p foo

Search the package of a file:

Have you ever wondered to which package belongs a given file? To get this information (e.g. for /usr/bin/apt-get), start the command

dpkg -S /usr/bin/apt-get

and it will tell you that this file is part of the package apt.