4.7 How can I check that I am using a Debian system, and what version is it?

In order to make sure that your system has been installed from the real Debian base disks check for the existence of /etc/debian_version file, which contains a single one-line entry giving the version number of the release, as defined by the package base-files.

The existence of the program dpkg shows that you should be able to install Debian packages on your system, but as the program has been ported to many other operating systems and architectures, this is no longer a reliable method of determining is a system Debian GNU/Linux.

Users should be aware, however, that the Debian system consists of many parts, each of which can be updated (almost) independently. Each Debian "release" contains well defined and unchanging contents. Updates are separately available. For a one-line description of the installation status of package foo, use the command dpkg --list foo. To view versions of all installed packages, run:

     dpkg -l

For a more verbose description, use:

     dpkg --status foo