Conventions

The following typographical conventions are used in this book:

Italic

Used for filenames and pathnames, hostnames, domain names, commands, URLs, and email addresses. Italic is also used for new terms where they are defined.

Constant width

Used for code examples and fragments.

Constant width bold

Used for user input.

Constant width italic

Used to indicate text that is replaceable.

Indicates a tip, suggestion, or general note.

Indicates a warning or caution.

One particularly important convention in this book involves the use of command line prompts. I can't say it too often: don't get into the habit of su'ing to root whenever you have to do anything remotely administrative. Even worse, don't say "It's my machine, I can do anything as root." Use root privileges only when you really need them. You'll be safer that way; you'll have some protection against your own mistakes, and against attacks made by outsiders.

To show you when you need root privileges, commands requiring root privileges are preceded by the root prompt, #. Commands that don't require root privileges are preceded by the default bash shell prompt, $.

Don't be confused—there are many file listings in the book, and in many of these files, comments are preceded by #. Yes, it can be confusing, but you'll get used to it.