Shell Prompts

This table shows the default system prompt and superuser prompt. The examples use these prompts to indicate which type of user is running the example.


Normal user




Typographic Conventions

This table describes the typographic conventions used in this book.


The names of commands.

Use ls -l to list all files.

The names of files.

Edit .login.

On-screen computer output.

You have mail.

What the user types, contrasted with on-screen computer output.

% date +"The time is %H:%M"
The time is 09:18

Manual page references.

Use su(1) to change user identity.

User and group names.

Only root can do this.


The user must do this.

Text that the user is expected to replace with the actual text.

To search for a keyword in the manual pages, type man -k keyword

Environment variables.

$HOME is set to the user’s home directory.

Notes, Tips, Important Information, Warnings, and Examples

Notes, warnings, and examples appear within the text.

Notes are represented like this, and contain information to take note of, as it may affect what the user does.

Tips are represented like this, and contain information helpful to the user, such as showing an easier way to do something.

Important information is represented like this. Typically, these show extra steps the user may need to take.

Warnings are represented like this, and contain information warning about possible damage if the instructions are not followed. This damage may be physical, to the hardware or the user, or it may be non-physical, such as the inadvertent deletion of important files.

Example 1. A Sample Example

Examples are represented like this, and typically contain examples showing a walkthrough, or the results of a particular action.


My thanks to Sue Blake, Patrick Durusau, Jon Hamilton, Peter Flynn, and Christopher Maden, who took the time to read early drafts of this document and offer many valuable comments and criticisms.

Last modified on: March 9, 2024 by Danilo G. Baio