Skip to Main Content
Regular Expression Pocket Reference, 2nd Edition
book

Regular Expression Pocket Reference, 2nd Edition

by Tony Stubblebine
July 2007
Intermediate to advanced content levelIntermediate to advanced
128 pages
2h 39m
English
O'Reilly Media, Inc.
Content preview from Regular Expression Pocket Reference, 2nd Edition

Supported Metacharacters

Ruby supports the metacharacters and metasequences listed in Table 32 through Table 37. For expanded definitions of each metacharacter, see "Regex Metacharacters, Modes, and Constructs.”

Table 1-32. Ruby character representations

Sequence

Meaning

\a

Alert (bell), \x07.

\b

Backspace, \x08, supported only in character class.

\e

ESC character, \x1B.

\n

Newline, \x0A.

\r

Carriage return, \x0D.

\f

Form feed, \x0C.

\t

Horizontal tab, \x09.

\v

Vertical tab, \x0B.

\0octal

Character specified by a two-digit octal code.

\xhex

Character specified by a two-digit hexadecimal code.

\cchar

Named control character.

Table 1-33. Ruby character classes and class-like constructs

Class

Meaning

[...]

A single character listed, or contained within a listed range.

[^...]

A single character not listed, and not contained within a listed range.

.

Any character, except a line terminator (unless single-line mode, s).

\w

Word character.

\W

Nonword character.

\d

Digit.

\D

Nondigit.

\s

Whitespace character, [ \f\n\r\t\v].

\S

Nonwhitespace character, [^ \f\n\r\t\v].

Table 1-34. Ruby anchors and other zero-width tests

Sequence

Meaning

^

Start of string, or the point after any newline.

\A

Beginning of string, in all match modes.

$

End of string, or the point before any newline.

\Z

End of string, but before any final line terminator, in all match modes.

\z

End of string, in all match modes.

\b

Boundary between a \w character and a \W character.

\B

Not-word-boundary.

\G

End of the previous match.

(?=...)

Positive lookahead.

(?!...)

Negative lookahead.

Table 1-35. Ruby ...

Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.
Start your free trial

You might also like

PHP Advanced for the World Wide Web: Visual QuickPro Guide

PHP Advanced for the World Wide Web: Visual QuickPro Guide

Larry Ullman
PHP 5 Power Programming

PHP 5 Power Programming

Andi Gutmans, Stig Sæther Bakken, Derick Rethans

Publisher Resources

ISBN: 9780596514273Errata Page