Conventions Used in This Book

The following conventions are used:

Italic

Represents file and directory names, function names, program variables, names of books and of chapters in this book, and general emphasis. In examples, it is used to insert comments that are not part of the text you type in. This is in italics.

Bold

Represents command names, options, keyboard keys, user names and C preprocessor directives, such as #if.

Constant Width

Represents programming language keywords such as int and struct. In examples, it is used to show program code, input or output files, and the output from commands and program runs.

Constant Width Bold

Used in examples to show commands or input that you enter at the terminal. e.g., "$ ls"

Constant Width Italic

Used in examples to show generic (variable) portions of a command that you should replace with specific words appropriate to your situation. For example:

          rm filename
          

means to type the command rm, followed by filename, the name of a file.

$

Used to show the shell prompt. The default shell prompt is different for different shells and can be changed by the user.

Two different notations are used in this book to represent the use of control keys. One is more familiar to most readers: the notation CTRL-X means you must hold down the Control key while typing the character "x". When discussing editor usage, we use the notation that its documentation uses: C-x means the same as CTRL-X. The shift key is irrelevant when you type a letter along with the Control key.

We denote other keys similarly (e.g., Return indicates a carriage return). All user input should be followed by a Return, unless otherwise indicated.