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| Preface |

## Conventions Used in This Handbook

We leave it as understood that, when you enter a shell command, you press RETURN at the end. RETURN is labeled ENTER on some keyboards.

Characters called CTRL-X, where X is any letter, are entered by holding down the CTRL (or CTL, or CONTROL) key and pressing that letter. Although we give the letter in uppercase, you can press the letter without the SHIFT key.

Other special characters are LINEFEED (which is the same as CTRL-J), BACKSPACE (same as CTRL-H), ESC, TAB, and DEL (sometimes labeled DELETE or RUBOUT).

This book uses the following font conventions:

Italic | is used for UNIX filenames, commands not built into the shell, (which are files anyway), and shell functions. Italic is also used for dummy parameters that should be replaced with an actual value, to distinguish the vi and emacs programs from their Korn-shell modes, and to highlight special terms the first time they are defined.
Bold | is used for Korn shell built-in commands, aliases, variables, and options, as well as command lines when they are within regular text. Bold is used for all elements typed in by the user.
`Constant Width` | is used in examples to show the contents of files or the output from commands.
> `Constant Bold` | is used in examples to show interaction between the user and the shell; any text the user types in is shown in `Constant Bold`. For example:
>     $ pwd
>     /users/billr/ora/kb
>     $
`Constant Italic` | is used in displayed command lines for dummy parameters that should be replaced with an actual value.
> Reverse Video | is used in Chapter 2 to show the position of the cursor on the command line being edited. For example:
>     grep -l Bob < ~pete/wk/names

Standard UNIX utility commands are sometimes mentioned with a number in parentheses (usually 1) following the command's name. The number refers to the section of the UNIX User's Manual in which you'll find reference documentation (a.k.a. "man page") on the utility in question. For example, grep(1) means you will find the man page for grep in Section 1.

Chapter Summary |  | Acknowledgments