UNIX Hints & Hacks		ContentsIndex
Introduction		Previous ChapterNext Chapter
Sections in this Chapter: UNIX Knowledge Needed   Symbols, Command Syntax, and Notations     Tested UNIX Flavors   Structure     Shells and Scripting Languages   About the Author     Before Beginning   Dedication     Hints & Hacks Topics   Acknowledgments     Examples: Commands, Functions, Routines, and Procedures		Previous SectionNext Section

Symbols, Command Syntax, and Notations

Throughout the book you'll find references to some of the more common reserved symbols that UNIX has to offer. The following symbols are used:

• A dollar sign ( $) represents a normal user shell account under the following shells: bsh and ksh. If this symbol is preceded by a command, the command is executed with the executing user's permission and ownership attached.
• A percent sign ( %) represents a normal user shell account under the C shell (csh). If this symbol is preceded by a command, the command is executed with the executing user's permission and ownership attached.

• A pound sign ( #) before a command represents that the command is to be executed with all rights and privileges granted to a superuser (or root) account. When used in a script it defines a comment within the script that doesn't get executed when processed.

• An ampersand ( &) forces a command or script to run as a background process. You will see this often throughout the book.
• The tilde ( ~) means the home directory of the current user.
• The asterisk ( *) is a wildcard matching zero or more characters.
• The question mark ( ?) is a wildcard matching only one character.
• The pipe ( |) sends the output of one command as input to another command.

You'll also see definitions of the command syntax (technical typographical notation) in this book alongside a clear, precise example of the command. If you are familiar with the syntax format of the man pages provided with UNIX, this syntax should be familiar to you. For example, in the command

  mt [-f] device {fsf|rew|offline|status} [count]

• All commands and literal arguments used in commands are in bold.

• Arguments that should not be taken literally, called placeholders, are in italic.
• The square brackets [ and ] represent optional arguments.
• The Curly braces { and } means that you should select an item that is separated by one of the vertical bars |. Do not confuse these vertical bars with the pipe symbol. They have different meanings.

All the output from commands and scripts will be left in a normal text. All the examples will be spelled out and understandable. In addition to the syntax, this book will provide clear usable examples:

$ mt -f /dev/tape fsf 1

UNIX Hints & Hacks		ContentsIndex
Introduction		Previous ChapterNext Chapter
Sections in this Chapter: UNIX Knowledge Needed   Symbols, Command Syntax, and Notations     Tested UNIX Flavors   Structure     Shells and Scripting Languages   About the Author     Before Beginning   Dedication     Hints & Hacks Topics   Acknowledgments     Examples: Commands, Functions, Routines, and Procedures		Previous SectionNext Section

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