The following conventions are used in this book:
Constant width
Used to indicate anything that might appear in a program, including keywords, function names, SQL commands, and variable names. This font is also used for code examples, output displayed by commands, and system configuration files.
Constant width bold
Used to indicate user input.
Constant width italic
Used to indicate an element (e.g., a filename or variable) that you supply.
Used to indicate directory names, filenames, program names, Unix commands, and URLs. This font is also used to introduce new terms and for emphasis.