Linux in a Nutshell, Fifth Edition

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Chapter 3: Linux Commands

This is the Title of the Book, eMatter Edition

Copyright © 2006 O’Reilly & Associates, Inc. All rights reserved.

-r n

Set the maximum read latency (basically, the number of

sectors to read before writes are allowed) to n. The default is

8192.

-v Print version number, then exit.

-w n

Set the maximum write latency (sectors to write before

allowing a read) to n. The default is 16384.

emacs

emacs [options] [files]

A text editor and all-purpose work environment. For more infor-

mation, see Chapter 8.

enable

enable -E [destination]

Enable printers or printer classes. Part of the CUPS system. More

often invoked as accept.

env

env [option] [variable=value ... ] [command]

Display the current environment or, if an environment variable is

specified, set it to a new value and display the modified environ-

ment. If command is specified, execute it under the modified

environment.

Options

-, -i, --ignore-environment

Ignore current environment entirely.

-u name, --unset name

Unset the specified variable.

--help

Print help message and then exit.

--version

Print version information and then exit.

envsubst

envsubst [options] [shell-format]

Substitutes environment variables in a shell string or script. When

used with no options, copies stdin to stdout, replacing any environ-

ment variable string, such as $VARIABLE or ${VARIABLE}, with

the appropriate environment variable value. So, “My editor is

$EDITOR”