Conventions Used in This Handbook (Learning the Korn Shell, 2nd Edition)

0.6. Conventions Used in This Handbook

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

Used when discussing Unix filenames, external and built-in commands, alias names, command options, shell options, and shell functions. Italic is also used in the text when discussing 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.

Constant width

Used for variable names and shell keywords, filename suffixes, and in examples to show the contents of files or the output from commands, as well as for command lines when they are within regular text.

Constant width bold

Used in examples to show interaction between the user and the shell; any text the user types in is shown in constant width bold. For example:

$ pwd
/home/billr/ora/kb
$

Constant width italic

Used in the text and in example command lines for dummy parameters that should be replaced with an actual value. For example:

$ cd directory

Reverse video

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

NOTE: Indicates a tip, suggestion, or general note.

WARNING: Indicates a warning or caution.

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. "the man page") on the utility in question. For example, grep(1) means the man page for grep in Section 1.

When there is an important difference between the 1988 and 1993 versions of the Korn shell, we refer to them as ksh88 and ksh93 respectively. Most of this book applies to all versions of the 1993 Korn shell. When we need to distinguish among different versions of the 1993 Korn shell, we add the minor release to the name, such as ksh93h, or ksh93l+.