@c This is part of the Emacs manual.
-@c Copyright (C) 1985-1987, 1993-1995, 1997, 2000-2012
-@c Free Software Foundation, Inc.
+@c Copyright (C) 1985-1987, 1993-1995, 1997, 2000-2013 Free Software
+@c Foundation, Inc.
@c See file emacs.texi for copying conditions.
@node Search
@chapter Searching and Replacement
(@pxref{Operating on Files}), or ask the @code{grep} program to do it
(@pxref{Grep Searching}).
-
@menu
* Incremental Search:: Search happens as you type the string.
* Nonincremental Search:: Specify entire string and then search.
* Word Search:: Search for sequence of words.
+* Symbol Search:: Search for a source code symbol.
* Regexp Search:: Search for match for a regexp.
* Regexps:: Syntax of regular expressions.
* Regexp Backslash:: Regular expression constructs starting with `\'.
@end table
@menu
-* Basic Isearch:: Basic incremental search commands.
-* Repeat Isearch:: Searching for the same string again.
-* Error in Isearch:: When your string is not found.
-* Special Isearch:: Special input in incremental search.
-* Isearch Yank:: Commands that grab text into the search string
- or else edit the search string.
-* Isearch Scroll:: Scrolling during an incremental search.
-* Isearch Minibuffer:: Incremental search of the minibuffer history.
+* Basic Isearch:: Basic incremental search commands.
+* Repeat Isearch:: Searching for the same string again.
+* Error in Isearch:: When your string is not found.
+* Special Isearch:: Special input in incremental search.
+* Isearch Yank:: Commands that grab text into the search string
+ or else edit the search string.
+* Not Exiting Isearch:: Prefix argument and scrolling commands.
+* Isearch Minibuffer:: Incremental search of the minibuffer history.
@end menu
@node Basic Isearch
@kindex M-e @r{(Incremental search)}
To edit the current search string in the minibuffer without
-replacing it with items from the search ring, type @kbd{M-e}. Type
+replacing it with items from the search ring, type @kbd{M-e}. Type @key{RET},
@kbd{C-s} or @kbd{C-r} to finish editing the string and search for it.
@node Error in Isearch
Some of the characters you type during incremental search have
special effects.
+@cindex lax space matching
+@kindex M-s SPC @r{(Incremental search)}
+@kindex SPC @r{(Incremental search)}
+@findex isearch-toggle-lax-whitespace
+@vindex search-whitespace-regexp
+ By default, incremental search performs @dfn{lax space matching}:
+each space, or sequence of spaces, matches any sequence of one or more
+spaces in the text. Hence, @samp{foo bar} matches @samp{foo bar},
+@samp{foo bar}, @samp{foo bar}, and so on (but not @samp{foobar}).
+More precisely, Emacs matches each sequence of space characters in the
+search string to a regular expression specified by the variable
+@code{search-whitespace-regexp}. For example, set it to
+@samp{"[[:space:]\n]+"} to make spaces match sequences of newlines as
+well as spaces. To toggle lax space matching, type @kbd{M-s SPC}
+(@code{isearch-toggle-lax-whitespace}). To disable this feature
+entirely, change @code{search-whitespace-regexp} to @code{nil}; then
+each space in the search string matches exactly one space
+
If the search string you entered contains only lower-case letters,
the search is case-insensitive; as long as an upper-case letter exists
in the search string, the search becomes case-sensitive. If you
@kindex M-% @r{(Incremental search)}
Typing @kbd{M-%} in incremental search invokes @code{query-replace}
or @code{query-replace-regexp} (depending on search mode) with the
-current search string used as the string to replace. @xref{Query
-Replace}.
+current search string used as the string to replace. A negative
+prefix argument means to replace backward. @xref{Query Replace}.
@kindex M-TAB @r{(Incremental search)}
Typing @kbd{M-@key{TAB}} in incremental search invokes
minibuffer with @kbd{M-e} (@pxref{Repeat Isearch}) and type @kbd{C-f}
at the end of the search string in the minibuffer.
-@node Isearch Scroll
-@subsection Scrolling During Incremental Search
+@node Not Exiting Isearch
+@subsection Not Exiting Incremental Search
+This subsection describes two categories of commands which you can
+type without exiting the current incremental search, even though they
+are not themselves part of incremental search.
+
+@table @asis
+@item Prefix Arguments
+@vindex isearch-allow-prefix
+ In incremental search, when you enter a prefix argument
+(@pxref{Arguments}), by default it will apply either to the next
+action in the search or to the command that exits the search.
+
+ In previous versions of Emacs, entering a prefix argument always
+terminated the search. You can revert to this behavior by setting the
+variable @code{isearch-allow-prefix} to @code{nil}.
+
+ When @code{isearch-allow-scroll} is non-@code{nil} (see below),
+prefix arguments always have the default behavior described above.
+
+@item Scrolling Commands
@vindex isearch-allow-scroll
Normally, scrolling commands exit incremental search. If you change
the variable @code{isearch-allow-scroll} to a non-@code{nil} value,
change point, the buffer contents, the match data, the current buffer,
or the selected window and frame. The command must not itself attempt
an incremental search.
+@end table
@node Isearch Minibuffer
@subsection Searching the Minibuffer
When the current match is on a history element, that history element
is pulled into the minibuffer. If you exit the incremental search
-normally (e.g. by typing @key{RET}), it remains in the minibuffer
+normally (e.g., by typing @key{RET}), it remains in the minibuffer
afterwards. Canceling the search, with @kbd{C-g}, restores the
contents of the minibuffer when you began the search.
proceeds incrementally as you type. This additional laxity does not
apply to the lazy highlight, which always matches whole words.
+@node Symbol Search
+@section Symbol Search
+@cindex symbol search
+
+ A @dfn{symbol search} is much like an ordinary search, except that
+the boundaries of the search must match the boundaries of a symbol.
+The meaning of @dfn{symbol} in this context depends on the major mode,
+and usually refers to a source code token, such as a Lisp symbol in
+Emacs Lisp mode. For instance, if you perform an incremental symbol
+search for the Lisp symbol @code{forward-word}, it would not match
+@code{isearch-forward-word}. This feature is thus mainly useful for
+searching source code.
+
+@table @kbd
+@item M-s _
+If incremental search is active, toggle symbol search mode
+(@code{isearch-toggle-symbol}); otherwise, begin an incremental
+forward symbol search (@code{isearch-forward-symbol}).
+@item M-s .
+Start a symbol incremental search forward with the symbol found near
+point added to the search string initially.
+@item M-s _ @key{RET} @var{symbol} @key{RET}
+Search forward for @var{symbol}, nonincrementally.
+@item M-s _ C-r @key{RET} @var{symbol} @key{RET}
+Search backward for @var{symbol}, nonincrementally.
+@end table
+
+@kindex M-s _
+@kindex M-s .
+@findex isearch-forward-symbol
+@findex isearch-forward-symbol-at-point
+ To begin a forward incremental symbol search, type @kbd{M-s _} (or
+@kbd{M-s .} if the symbol to search is near point). If incremental
+search is not already active, this runs the command
+@code{isearch-forward-symbol}. If incremental search is already
+active, @kbd{M-s _} switches to a symbol search, preserving the
+direction of the search and the current search string; you can disable
+symbol search by typing @kbd{M-s _} again. In incremental symbol
+search, only the beginning of the search string is required to match
+the beginning of a symbol.
+
+ To begin a nonincremental symbol search, type @kbd{M-s _ @key{RET}}
+for a forward search, or @kbd{M-s _ C-r @key{RET}} or a backward
+search. In nonincremental symbol searches, the beginning and end of
+the search string are required to match the beginning and end of a
+symbol, respectively.
+
@node Regexp Search
@section Regular Expression Search
@cindex regexp search
They also have separate search rings, which you can access with
@kbd{M-p} and @kbd{M-n}.
-@vindex search-whitespace-regexp
- If you type @key{SPC} in incremental regexp search, it matches any
-sequence of whitespace characters, including newlines. If you want to
-match just a space, type @kbd{C-q @key{SPC}}. You can control what a
-bare space matches by setting the variable
-@code{search-whitespace-regexp} to the desired regexp.
+ Just as in ordinary incremental search, any @key{SPC} typed in
+incremental regexp search matches any sequence of one or more
+whitespace characters. The variable @code{search-whitespace-regexp}
+specifies the regexp for the lax space matching, and @kbd{M-s SPC}
+(@code{isearch-toggle-lax-whitespace}) toggles the feature.
+@xref{Special Isearch}.
In some cases, adding characters to the regexp in an incremental
regexp search can make the cursor move back and start again. For
tries to match all three @samp{a}s; but the rest of the pattern is
@samp{ar} and there is only @samp{r} left to match, so this try fails.
The next alternative is for @samp{a*} to match only two @samp{a}s.
-With this choice, the rest of the regexp matches successfully.@refill
+With this choice, the rest of the regexp matches successfully.
@item @kbd{+}
is a postfix operator, similar to @samp{*} except that it must match
match @var{a}, and if that fails, by trying to match @var{b}.
Thus, @samp{foo\|bar} matches either @samp{foo} or @samp{bar}
-but no other string.@refill
+but no other string.
@samp{\|} applies to the largest possible surrounding expressions. Only a
surrounding @samp{\( @dots{} \)} grouping can limit the grouping power of
-@samp{\|}.@refill
+@samp{\|}.
Full backtracking capability exists to handle multiple uses of @samp{\|}.
To enclose a complicated expression for the postfix operators @samp{*},
@samp{+} and @samp{?} to operate on. Thus, @samp{ba\(na\)*} matches
@samp{bananana}, etc., with any (zero or more) number of @samp{na}
-strings.@refill
+strings.
@item
To record a matched substring for future reference.
matches the empty string, but only at the beginning or
end of a word. Thus, @samp{\bfoo\b} matches any occurrence of
@samp{foo} as a separate word. @samp{\bballs?\b} matches
-@samp{ball} or @samp{balls} as a separate word.@refill
+@samp{ball} or @samp{balls} as a separate word.
@samp{\b} matches at the beginning or end of the buffer
regardless of what text appears next to it.
you specify searching for @samp{foo}, then @samp{Foo} and @samp{foo}
also match. Regexps, and in particular character sets, behave
likewise: @samp{[ab]} matches @samp{a} or @samp{A} or @samp{b} or
-@samp{B}.@refill
+@samp{B}.
An upper-case letter anywhere in the incremental search string makes
the search case-sensitive. Thus, searching for @samp{Foo} does not find
is possible to perform several replacements in parallel, using the
command @code{expand-region-abbrevs} (@pxref{Expanding Abbrevs}).
+@vindex replace-lax-whitespace
+ Unlike incremental search, the replacement commands do not use lax
+space matching (@pxref{Special Isearch}) by default. To enable lax
+space matching for replacement, change the variable
+@code{replace-lax-whitespace} to @code{t}. (This only affects how
+Emacs finds the text to replace, not the replacement text.)
+
@menu
* Unconditional Replace:: Replacing all matches for a string.
* Regexp Replace:: Replacing all matches for a regexp.
(@pxref{Unconditional Replace}). In particular, it preserves case
provided @code{case-replace} is non-@code{nil}, as it normally is
(@pxref{Replacement and Case}). A numeric argument means to consider
-only occurrences that are bounded by word-delimiter characters.
+only occurrences that are bounded by word-delimiter characters. A
+negative prefix argument replaces backward.
@kindex C-M-%
@findex query-replace-regexp
@item !
to replace all remaining occurrences without asking again.
+@item Y @r{(Upper-case)}
+to replace all remaining occurrences in all remaining buffers in
+multi-buffer replacements (like the Dired `Q' command which performs
+query replace on selected files). It answers this question and all
+subsequent questions in the series with "yes", without further
+user interaction.
+
+@item N @r{(Upper-case)}
+to skip to the next buffer in multi-buffer replacements without
+replacing remaining occurrences in the current buffer. It answers
+this question "no", gives up on the questions for the current buffer,
+and continues to the next buffer in the sequence.
+
@item ^
to go back to the position of the previous occurrence (or what used to
be an occurrence), in case you changed it by mistake or want to