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Changes to html_node/Special-Backslash-Expressions.html
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From: |
Jim Meyering |
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Subject: |
Changes to html_node/Special-Backslash-Expressions.html |
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Date: |
Sat, 3 Sep 2022 15:33:16 -0400 (EDT) |
CVSROOT: /webcvs/grep
Module name: grep
Changes by: Jim Meyering <meyering> 22/09/03 15:33:15
Index: html_node/Special-Backslash-Expressions.html
===================================================================
RCS file: html_node/Special-Backslash-Expressions.html
diff -N html_node/Special-Backslash-Expressions.html
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ html_node/Special-Backslash-Expressions.html 3 Sep 2022 19:33:14
-0000 1.1
@@ -0,0 +1,130 @@
+<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd";>
+<html>
+<!-- Created by GNU Texinfo 6.8, https://www.gnu.org/software/texinfo/ -->
+<head>
+<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
+<!-- This manual is for grep, a pattern matching engine.
+
+Copyright (C) 1999-2002, 2005, 2008-2022 Free Software Foundation,
+Inc.
+
+Permission is granted to copy, distribute and/or modify this document
+under the terms of the GNU Free Documentation License, Version 1.3 or
+any later version published by the Free Software Foundation; with no
+Invariant Sections, with no Front-Cover Texts, and with no Back-Cover
+Texts. A copy of the license is included in the section entitled
+"GNU Free Documentation License". -->
+<title>Special Backslash Expressions (GNU Grep 3.8)</title>
+
+<meta name="description" content="Special Backslash Expressions (GNU Grep
3.8)">
+<meta name="keywords" content="Special Backslash Expressions (GNU Grep 3.8)">
+<meta name="resource-type" content="document">
+<meta name="distribution" content="global">
+<meta name="Generator" content="makeinfo">
+<meta name="viewport" content="width=device-width,initial-scale=1">
+
+<link href="index.html" rel="start" title="Top">
+<link href="Index.html" rel="index" title="Index">
+<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents">
+<link href="Regular-Expressions.html" rel="up" title="Regular Expressions">
+<link href="Anchoring.html" rel="next" title="Anchoring">
+<link href="Character-Classes-and-Bracket-Expressions.html" rel="prev"
title="Character Classes and Bracket Expressions">
+<style type="text/css">
+<!--
+a.copiable-anchor {visibility: hidden; text-decoration: none; line-height: 0em}
+a.summary-letter {text-decoration: none}
+blockquote.indentedblock {margin-right: 0em}
+div.display {margin-left: 3.2em}
+div.example {margin-left: 3.2em}
+kbd {font-style: oblique}
+pre.display {font-family: inherit}
+pre.format {font-family: inherit}
+pre.menu-comment {font-family: serif}
+pre.menu-preformatted {font-family: serif}
+span.nolinebreak {white-space: nowrap}
+span.roman {font-family: initial; font-weight: normal}
+span.sansserif {font-family: sans-serif; font-weight: normal}
+span:hover a.copiable-anchor {visibility: visible}
+ul.no-bullet {list-style: none}
+-->
+</style>
+<link rel="stylesheet" type="text/css"
href="https://www.gnu.org/software/gnulib/manual.css";>
+
+
+</head>
+
+<body lang="en">
+<div class="section" id="Special-Backslash-Expressions">
+<div class="header">
+<p>
+Next: <a href="Anchoring.html" accesskey="n" rel="next">Anchoring</a>,
Previous: <a href="Character-Classes-and-Bracket-Expressions.html"
accesskey="p" rel="prev">Character Classes and Bracket Expressions</a>, Up: <a
href="Regular-Expressions.html" accesskey="u" rel="up">Regular Expressions</a>
[<a href="index.html#SEC_Contents" title="Table of contents"
rel="contents">Contents</a>][<a href="Index.html" title="Index"
rel="index">Index</a>]</p>
+</div>
+<hr>
+<span id="Special-Backslash-Expressions-1"></span><h3 class="section">3.3
Special Backslash Expressions</h3>
+<span id="index-backslash"></span>
+
+<p>The ‘<samp>\</samp>’ character followed by a special character
is a regular
+expression that matches the special character.
+The ‘<samp>\</samp>’ character,
+when followed by certain ordinary characters,
+takes a special meaning:
+</p>
+<dl compact="compact">
+<dt><span>‘<samp>\b</samp>’</span></dt>
+<dd><p>Match the empty string at the edge of a word.
+</p>
+</dd>
+<dt><span>‘<samp>\B</samp>’</span></dt>
+<dd><p>Match the empty string provided it’s not at the edge of a word.
+</p>
+</dd>
+<dt><span>‘<samp>\<</samp>’</span></dt>
+<dd><p>Match the empty string at the beginning of a word.
+</p>
+</dd>
+<dt><span>‘<samp>\></samp>’</span></dt>
+<dd><p>Match the empty string at the end of a word.
+</p>
+</dd>
+<dt><span>‘<samp>\w</samp>’</span></dt>
+<dd><p>Match word constituent, it is a synonym for
‘<samp>[_[:alnum:]]</samp>’.
+</p>
+</dd>
+<dt><span>‘<samp>\W</samp>’</span></dt>
+<dd><p>Match non-word constituent, it is a synonym for
‘<samp>[^_[:alnum:]]</samp>’.
+</p>
+</dd>
+<dt><span>‘<samp>\s</samp>’</span></dt>
+<dd><p>Match whitespace, it is a synonym for
‘<samp>[[:space:]]</samp>’.
+</p>
+</dd>
+<dt><span>‘<samp>\S</samp>’</span></dt>
+<dd><p>Match non-whitespace, it is a synonym for
‘<samp>[^[:space:]]</samp>’.
+</p>
+</dd>
+<dt><span>‘<samp>\]</samp>’</span></dt>
+<dd><p>Match ‘<samp>]</samp>’.
+</p>
+</dd>
+<dt><span>‘<samp>\}</samp>’</span></dt>
+<dd><p>Match ‘<samp>}</samp>’.
+</p>
+</dd>
+</dl>
+
+<p>For example, ‘<samp>\brat\b</samp>’ matches the separate word
‘<samp>rat</samp>’,
+‘<samp>\Brat\B</samp>’ matches ‘<samp>crate</samp>’
but not ‘<samp>furry rat</samp>’.
+</p>
+<p>The behavior of <code>grep</code> is unspecified if a unescaped backslash
+is not followed by a special character, a nonzero digit, or a
+character in the above list. Although <code>grep</code> might issue a
+diagnostic and/or give the backslash an interpretation now, its
+behavior may change if the syntax of regular expressions is extended
+in future versions.
+</p>
+</div>
+
+
+
+</body>
+</html>
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