Introducing Debian packages
You may have heard of Debian, a well-known Linux distribution that was first released in 1993. Ubuntu is based on Debian, and many Ubuntu developers are also Debian developers. Debian contains tens of thousands of well-maintained software packages.
Debian packages were designed for use by dpkg, a command-line tool for working with Debian packages. These packages contain a bundle of files that are part of the application or sometimes a bundle of files necessary for other applications to run. Each package declares other packages it depends on, which are required to function as expected. Due to the nature of these dependencies, apt was invented as a tool to resolve dependencies based on an online repository of Debian packages. It also handles downloading these packages from the online repositories.
Figure 6.1 – Package dependency graph
The package dependency graph in Figure 6.1 shows that package a depends on packages b, c, and d. Package...
