Linux in a Nutshell, 6th Edition

Conventions

This desktop quick reference follows certain typographic conventions:

Bold

Used for commands, programs, and options. All terms shown in bold are typed literally.

Italic

Used to show arguments and variables that should be replaced with user-supplied values. Italic is also used to introduce new terms, indicate filenames and directories, and to highlight comments in examples.

Constant width

Used to show the contents of files or the output from commands.

Constant width bold

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

Constant width italic

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

$

Used in some examples as the bash shell prompt ($).

[ ]

Surround optional elements in a description of syntax. (The brackets themselves should never be typed.) Note that many commands show the argument [files]. If a filename is omitted, standard input (e.g., the keyboard) is assumed. End with an end-of-file character.

EOF

Indicates the end-of-file character (normally Ctrl-D).

|

Used in syntax descriptions to separate items for which only one alternative may be chosen at a time.

Tip

This icon indicates a note, which is an important aside to its nearby text.

Warning

This icon indicates a warning.

A final word about syntax. In many cases, the space between an option and its argument can be omitted. In other cases, the spacing (or lack of spacing) must be followed strictly. For example, -wn (no intervening space) might be interpreted ...