Conventions Used in This Book

The following typographical conventions are used in this book:


Indicates new terms, URLs, email addresses, filenames, file extensions, pathnames, directories, and Unix utilities.

Constant width

Indicates commands, options, switches, variables, attributes, keys, functions, types, classes, namespaces, methods, modules, properties, parameters, values, objects, events, event handlers, XML tags, HTML tags, macros, the contents of files, or the output from commands.

Constant width bold

Used in examples and tables to show commands or other text that should be typed literally by the user.

Constant width italic

Used in examples, tables, and commands to show text that should be replaced with user-supplied values.


The second color is used to indicate a cross-reference within the text.

This icon signifies a tip, suggestion, or general note.

This icon indicates a warning or caution.

The thermometer icons, found next to each hack, indicate the relative complexity of the hack:

figs/beginner.gif beginner
figs/moderate.gif moderate
figs/expert.gif expert