Here is basic information on how to install software on your system. You should have read the article Opening a terminal beforehand.
Table of contents
The Debian package management
Debian is – like most Linux systems a system – which at individual software packages based. A software package is an organized Collection of files, Installation- and Uninstallation routines, packed into a file and install it if needed or again uninstall without leaving any residue can be.
These packages in turn are organized in package archives, so-called repositories, which can contain many individual packages.
Debian package management can handle repositories on existing CDs or DVDs as well as – and this is the more common case – package archives on the Internet. Safety updates are available exclusively via the Internet. Provided that one would like to access the current software versions, an Internet connection is thus a condition.
Furthermore the standard Debian package includes a very comprehensive archive of available software is included – currently over 50.000 different packages. This large selection of packages is usually sufficient for all purposes. Also these packages often have Dependencies. These dependencies are caused by the system itself automatically dissolved. If z. B. an audio player requires a graphical user interface, then the program automatically indicates that this must also be installed if the audio player is to be installed.
package name in forum and wiki
If you see a link with the Debian logo in the forum or in the wiki, like here – inxi – it means that this is a name of a Debian package that you can install – as described on this page.
console or graphical tool
Debian offers both the way over the Linux console and a graphical tool for package management.
If you have installed GNOME – the standard graphical system – then you can delete packages via the menu Activities with the search term Packages find and run the software installation utility of the same name. Here you can search for the desired programs and install them after entering the root password.
The commands for package management for the console are explained in more detail below.
Package management on the command line
The basic tool for software installation is called apt-get. The program to search for packages is called apt-cache.
Update package lists
Like the world, Debian is constantly changing. New versions of software packages are released regularly. That’s why it’s good to update the list of available software packages before installing software. Please open a root shell and execute this command.
Every user of a system has the right to browse the package archives. In the present case, we already have a package name, namely inxi . To make sure that the package is present and that we have the correct package name, we search the package archive again for this name.
This command will search for all packages that are inxi in the package name and it gives us a list with package name and short description:
If you want to extend the search to the description, leave the option –names-only away.
Only the superuser is allowed to install packages. Therefore you need a root shell and install the package inxi with the package name.
If the package needs more packages – so called dependencies – then the system asks you if you agree to install the package with all the dependencies. In the example of inxi it looks like this:
so inxi needs another 6 additional software packages, so 7 packages in total, which consume an additional 4.3 MB after installation. Furthermore it suggests 8 packages, which are not mandatory and therefore not installed automatically. If you want to do that, you can use as additional option at apt-get —install-suggests directly after apt-get, that is:
If we agree that the software will be installed, we confirm with y and Enter . Then we download and configure the program. If necessary, the system will ask us for information about the desired configuration. Since inxi is a simple program, no questions are asked. The program is now installed and can be used.
Even deleting packages is only allowed by the superuser. So if we want to delete inxi again, we enter:
When deleting a package, we are always asked if we really want to delete it:
By default, only the desired package is removed and not the additional installed packages that were required as dependencies. Since we also want to do this, we additionally give the option –auto-remove an. As we agree to uninstall the software now, we confirm with y and enter .
If we want to, we can clean up a little bit now. Debian keeps the downloaded packages on disk. If we decide to install inxi again, we don’t need to download it from the internet, but use it directly from the local cache.
The package cache is located in the directory /var/cache/apt/archives.
In this way we accumulate some hundred MB or more over time. If we want to clear this cache: This can be done as root with the command:
Get information about the package
If we have installed a program, then we also want to use it. In the simplest case, the program itself has created an entry in the menus in the graphical interface, which we only need to find.
If it’s not a graphical program, or want to look up what the program has installed, we can find out via the command line. The Low-Level Package manager dpkg provides information about installed packages. So let’s look at the file list of inxi:
This is the list of files installed by the package inxi. The number is quite manageable, because inxi is only a small package. The storage structure (FHS) can be clearly seen here:
- Below /etc configuration files are stored. Here it is inxi.conf
- Below /usr/share/doc/PAKETNAME is used to store documentation on how to use the software package
- If the package brings a formatted help file called – man-page called – it will be installed under /usr/share/man stored. This help file can be viewed via the man-Show command. Here it would be: man inxi
- The most important thing, of course, are the installed programs, which, depending on the type of software package, are listed for use by normal users under /bin or /usr/bin are stored. Commands that are intended for use by the administrator – because they usually require elevated privileges – are stored under /sbin or /usr/sbin filed. So Inxi installs only a single user program called /usr/bin/inxi, that on the command line with inxi can be executed.
- commands for the administrator can usually be executed as a user as well. However, since the search path for the administrator programs are not entered in the user’s search path, you have to run the programs with the full path name. However, since administrator commands usually require elevated privileges, executing adminstrator commands as a user will usually fail.
Filter filenames from packages
Not every package is as small as inxi. It can contain already once several thousands files. This is hundreds of screen pages full. In order to get the desired information even for large packages, we will filter the output. For a display of the programs we use this command:
So we only see installed programs from the list of installed files. With this method we can view the above mentioned different types of files in detail.
Each program usually has several types of documentation supplied with it, which are best read in the order listed here.
You can get the included manpages found out above by using the man-View command on the console. More about this under man .
Documentation under /usr/share/doc/PAKETNAME
The files can be viewed with an editor. See editor
Help by command line parameters
Common are also parameters built into the programs, which give help to call the program. Common are one or more of the parameters -?, -h or —help.
|hint: Running unknown programs, whose function you do not know, can have undesirable consequences. Therefore it is better to use the other possibilities first. Only then run the program itself and even then only as a user and not immediately as administrator(root).|
Inxi supported by the listed parameters -h and –help, but not -?.