www.delorie.com/gnu/docs/regex/regex_6.html   search  
 
Buy the book!


Regex

[ < ] [ > ]   [ << ] [ Up ] [ >> ]         [Top] [Contents] [Index] [ ? ]

2.4 The Backslash Character

The `\' character has one of four different meanings, depending on the context in which you use it and what syntax bits are set (see section 2.1 Syntax Bits). It can: 1) stand for itself, 2) quote the next character, 3) introduce an operator, or 4) do nothing.

  1. It stands for itself inside a list (see section 3.6 List Operators ([ ... ] and [^ ... ])) if the syntax bit RE_BACKSLASH_ESCAPE_IN_LISTS is not set. For example, `[\]' would match `\'.

  2. It quotes (makes ordinary, if it's special) the next character when you use it either:

  3. It introduces an operator when followed by certain ordinary characters--sometimes only when certain syntax bits are set. See the cases RE_BK_PLUS_QM, RE_NO_BK_BRACES, RE_NO_BK_VAR, RE_NO_BK_PARENS, RE_NO_BK_REF in 2.1 Syntax Bits. Also:

  4. In all other cases, Regex ignores `\'. For example, `\n' matches `n'.


[ < ] [ > ]   [ << ] [ Up ] [ >> ]         [Top] [Contents] [Index] [ ? ]

  webmaster   donations   bookstore     delorie software   privacy  
  Copyright 2003   by The Free Software Foundation     Updated Jun 2003