is used for statements and functions, identifiers, and program names.
is used for file and directory names when they appear in the body
of a paragraph as well as for data types and to emphasize new terms
and concepts when they are introduced.
is used in examples to show the contents of files or the output from commands.
is used in examples to show command lines and options
that should be typed literally by the user. (For example,
means to type "rm foo" exactly as it
appears in the text or the example.)
are used to identify a code fragment in explanatory text. System messages
and symbols are quoted as well.
is the UNIX Bourne shell or Korn shell prompt.
surrounds optional elements in a description of program syntax. (The
brackets themselves should never be typed, unless otherwise noted.)
stands for text (usually computer output) that's been omitted for
clarity or to save space.
indicates a literal space. This symbol is used to make spaces visible in
examples, as well as in the text.
indicates a literal TAB character. This symbol is
used to make tabs visible in examples, as well as in the text.
The notation CTRL-X or ^X
indicates use of control characters. It means hold down the "control"
key while typing the character "x". We denote other keys similarly
(e.g., RETURN indicates a carriage return). All examples of command
lines are followed by a RETURN unless otherwise indicated.