Linux in a Nutshell, Fifth Edition

758

|

Chapter 10: The sed Editor

This is the Title of the Book, eMatter Edition

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

Braces ({}) are used in sed to nest one address inside another or to apply multiple

commands at a single matched address:

[/pattern/[,/pattern/]]{

command1

command2

}

The opening curly brace must end its line, and the closing curly brace must be on

a line by itself. Be sure there are no spaces after the braces.

GNU sed Regular Expression Extensions

With the -r option, GNU sed uses Extended Regular Expressions instead of Basic

Regular expressions. (See Chapter 7 for more information.) However, even

without -r, you can use additional escape sequences for more powerful text

matching. The following escape sequences are valid only in regular expressions:

\b Matches on a word boundary, where of the two surrounding characters (x\by),

one is a word-constituent character and the other is not.

\B Matches on a non-word boundary, where both of the two surrounding char-

acters (x\by) are either word-constituent or not word-constituent.

\w Matches any word-constituent character (i.e., a letter, digit, or underscore).

\W Matches any non-word-constituent character (i.e., anything that is not a

letter, digit, or underscore).

\` Matches the beginning of the pattern space. This is different from ^ when the

m modifier is used for a pattern or the s command.

\' Matches the end of ...