Package Management & Program Installation Flashcards
Why do you need a package manager?
A Package Manager is used to simplify the installation and the removal of programs.
If one package requires another one, it is automatically installed as well.
Typically, package managers can handle updates and system upgrades, too.
=> a package manager presents a complete, centralised installation system
Which package form does the Debian package manager accept?
.deb
Which package manager uses ubuntu?
Uses the debian package management system
What is contained in a .deb package?
Such a package is, in principle, a compressed archive containing the program in binary form along with special control files that are interpreted by the package manager. These files contain information about the package, including its dependencies.
What’s the command name for the Debian package manager?
dpkg
What does APT stand for?
Advanced Packaging Tool
What is APT? What does it do?
The Advanced Packaging Tool (APT) is a frontend to dpkg. It handles package retrieval and package querying, as well as the resolution of dependencies. Internally, APT calls “dpkg” to install or remove packages.
Name a console-based package manager
aptitude
Name a GUI package manager
Synaptics
Which tool is the most convenient for Ubuntu home users for their software installation?
Ubuntu Software Center
From which sources can software be installed?
any removable (CD, USB) or non-removable media (internet)
How can you search within the package database?
APT maintains a package database, where meta information (name, dependencies and description) is stored. The option “search” allows to search within the database
How do you keep your package database up-to-date?
If you are connected to the Internet:
The tool “apt-get” is responsible for updating the database.
What could happen if your database is not up-to-date?
Program downloads may fail due to outdated information
In which 2 ways can programs be installed?
- if locally available via the debian package using dpkg -I
- if found via apt-cache, it can be installed using apt-get (download from the internet or a CD-Rom)
Which two options do you have if you want to remove a program?
You can either leave the configuration files in place (remove) or by deleting the configuration files as well (purge).
Both methods are provided and handled by tools already discussed, apt-get and dpkg
How does the updating process work?
Whenever a new version of a program is released, the local package database is updated. BUT no installation is performed. In order to install those updates, the command apt-get upgrade installs the new version of all available packages.
What can you do if there is no package available for a required program?
Build the program from source. The build process, involving the compilation of the source files, creates a binary, runable program.
How does the compiling a program from source work?
At first, some necessary prerequisites, for instance libraries needed by the program to build, have to be installed. This can be done either via the package manager or by building them from source as well. Then, the source code has to be downloaded and unpacked to a local directory. Afterwards, the actual compilation process can be started and after completion, the program can be installed and/or executed.
How can you get a program’s source code?
Download from the internet:
- as a compressed archive directly from the homepage
- repositories for version control, like Subversion (SVN), git or Mercurial (hg).
- websites to look for open source projects are github.com and sourceforge.net
Where can you find information on how to build the program?
INSTALL, README files
What does tar stand for?
The name “tar” is short for “tape archive” and comes out of historic reasons when backups of files were performed on tapes.
What are patches?
Fixes to errors or new features not made by the original author.
