Conventions Used in This Book

The following typographic conventions are used in this book:


Used for file and directory names, email addresses, Unix commands, and URLs, as well as for new terms where they are defined.

Constant Width

Used for code listings and for keywords, variables, tags, functions, command options, and strings where they appear in the text.

Constant Width Bold

Used to mark lines of output in examples.

Constant Width Italic

Used as a general placeholder to indicate items that should be replaced by actual values.

This icon designates a note, which is an important aside to the nearby text.

This icon designates a warning relating to the nearby text.