Conventions

In this book, you will find a number of text styles that distinguish between different kinds of information. Here are some examples of these styles and an explanation of their meaning.

Code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles are shown as follows: "The apt-get check command is a diagnostic tool for package management."

A block of code is set as follows:

zone "ubuntuserver.org" {
  type slave;
  file "sec.ubuntuserver.org";
  masters {10.200.12.68;};
};

Any command-line input or output is written as follows:

sudo apt-cache rdepends ssl-cert

New terms and important words are shown in bold. Words that you see on the screen, for example, in menus or dialog boxes, appear in the text like this: "The second line, New Packages, shows the number of packages that are new and can be installed on your Ubuntu Server."