@c This is part of the Emacs manual.
-@c Copyright (C) 1985, 86, 87, 93, 94, 95, 97, 2000, 2001
+@c Copyright (C) 1985, 1986, 1987, 1993, 1994, 1995, 1997, 2000, 2001, 2004
@c Free Software Foundation, Inc.
@c See file emacs.texi for copying conditions.
@node Search, Fixit, Display, Top
asks interactively which occurrences to replace.
@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.
-* Regexp Search:: Search for match for a regexp.
-* Regexps:: Syntax of regular expressions.
-* Search Case:: To ignore case while searching, or not.
-* Replace:: Search, and replace some or all matches.
-* Other Repeating Search:: Operating on all matches for some regexp.
+* Incremental Search:: Search happens as you type the string.
+* Nonincremental Search:: Specify entire string and then search.
+* Word Search:: Search for sequence of words.
+* Regexp Search:: Search for match for a regexp.
+* Regexps:: Syntax of regular expressions.
+* Search Case:: To ignore case while searching, or not.
+* Configuring Scrolling:: Scrolling within incremental search.
+* Replace:: Search, and replace some or all matches.
+* Other Repeating Search:: Operating on all matches for some regexp.
@end menu
@node Incremental Search, Nonincremental Search, Search, Search
@key{RET} is necessary only if the next command you want to type is a
printing character, @key{DEL}, @key{RET}, or another character that is
special within searches (@kbd{C-q}, @kbd{C-w}, @kbd{C-r}, @kbd{C-s},
-@kbd{C-y}, @kbd{M-y}, @kbd{M-r}, @kbd{M-s}, and some other
+@kbd{C-y}, @kbd{M-y}, @kbd{M-r}, @kbd{M-c}, @kbd{M-e}, and some other
meta-characters).
Sometimes you search for @samp{FOO} and find one, but not the one you
To reuse earlier search strings, use the @dfn{search ring}. The
commands @kbd{M-p} and @kbd{M-n} move through the ring to pick a search
string to reuse. These commands leave the selected search ring element
-in the minibuffer, where you can edit it. Type @kbd{C-s} or @kbd{C-r}
+in the minibuffer, where you can edit it. To edit the current search
+string in the minibuffer without replacing it with items from the
+search ring, type @kbd{M-e}. Type @kbd{C-s} or @kbd{C-r}
to terminate editing the string and search for it.
If your string is not found at all, the echo area says @samp{Failing
treated in the same context. You can also specify a character by its
octal code: enter @kbd{C-q} followed by a sequence of octal digits.
-@cindex searching for non-ASCII characters
+@cindex searching for non-@acronym{ASCII} characters
@cindex input method, during incremental search
- To search for non-ASCII characters, you must use an input method
+ To search for non-@acronym{ASCII} characters, you must use an input method
(@pxref{Input Methods}). If an input method is enabled in the
current buffer when you start the search, you can use it while you
type the search string also. Emacs indicates that by including the
backward search finds matches that are entirely before the starting
point, just as a forward search finds matches that begin after it.
- The characters @kbd{C-y} and @kbd{C-w} can be used in incremental
+ The characters @kbd{C-w} and @kbd{C-y} can be used in incremental
search to grab text from the buffer into the search string. This
makes it convenient to search for another occurrence of text at point.
@kbd{C-w} copies the character or word after point as part of the
character or word.
@kbd{C-y} is similar to @kbd{C-w} but copies all the rest of the
-current line into the search string. Both @kbd{C-y} and @kbd{C-w}
-convert the text they copy to lower case if the search is currently
-not case-sensitive; this is so the search remains case-insensitive.
+current line into the search string. If point is already at the end
+of a line, it grabs the entire next line. Both @kbd{C-y} and
+@kbd{C-w} convert the text they copy to lower case if the search is
+currently not case-sensitive; this is so the search remains
+case-insensitive.
+
+ @kbd{C-M-w} and @kbd{C-M-y} modify the search string by only one
+character at a time: @kbd{C-M-w} deletes the last character from the
+search string and @kbd{C-M-y} copies the character after point to the
+end of the search string. An alternative method to add the character
+after point into the search string is to enter the minibuffer by
+@kbd{M-e} and to type @kbd{C-f} at the end of the search string in the
+minibuffer.
The character @kbd{M-y} copies text from the kill ring into the search
string. It uses the same text that @kbd{C-y} as a command would yank.
there. In Transient Mark mode, incremental search sets the mark without
activating it, and does so only if the mark is not already active.
+ @kbd{M-%} typed 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.
+
@cindex lazy search highlighting
@vindex isearch-lazy-highlight
When you pause for a little while during incremental search, it
of bindings, look at the documentation of @code{isearch-mode} with
@kbd{C-h f isearch-mode @key{RET}}.
+@subsection Scrolling During Incremental Search
+
+ Vertical scrolling during incremental search can be enabled by
+setting the customizable variable @code{isearch-allow-scroll} to a
+non-@code{nil} value.
+
+ You can then use the vertical scroll-bar or certain keyboard
+commands such as @kbd{@key{PRIOR}} (@code{scroll-down}),
+@kbd{@key{NEXT}} (@code{scroll-up}) and @kbd{C-l} (@code{recenter})
+within the search, thus letting you see more of the text near the
+current match. You must run these commands via their key sequences to
+stay in the search---typing M-x @var{comand-name} will always
+terminate a search.
+
+ You can give prefix arguments to these commands in the usual way.
+The current match cannot be scrolled out of the window---this is
+intentional.
+
+ Several other commands, such as @kbd{C-x 2}
+(@code{split-window-vertically}) and @kbd{C-x ^}
+(@code{enlarge-window}) which don't scroll the window, are
+nevertheless made available under this rubric, since they are likewise
+handy during a search.
+
+ For a list of commands which are configured as scrolling commands by
+default and instructions on how thus to configure other commands, see
+@ref{Configuring Scrolling}.
+
@subsection Slow Terminal Incremental Search
Incremental search on a slow terminal uses a modified style of display
@kindex C-M-r
@findex isearch-backward-regexp
Incremental search for a regexp is done by typing @kbd{C-M-s}
-(@code{isearch-forward-regexp}), or by invoking @kbd{C-s} with a
-prefix argument (whose value does not matter). This command reads a
+(@code{isearch-forward-regexp}), by invoking @kbd{C-s} with a
+prefix argument (whose value does not matter), or by typing @kbd{M-r}
+within a forward incremental search. This command reads a
search string incrementally just like @kbd{C-s}, but it treats the
search string as a regexp rather than looking for an exact match
against the text in the buffer. Each time you add text to the search
string, you make the regexp longer, and the new regexp is searched
for. To search backward for a regexp, use @kbd{C-M-r}
-(@code{isearch-backward-regexp}), or @kbd{C-r} with a prefix argument.
+(@code{isearch-backward-regexp}), @kbd{C-r} with a prefix argument,
+or @kbd{M-r} within a backward incremental search.
All of the control characters that do special things within an
ordinary incremental search have the same function in incremental regexp
This manual describes regular expression features that users
typically want to use. There are additional features that are
mainly used in Lisp programs; see @ref{Regular Expressions,,,
-elisp, the same manual}.
+elisp, The Emacs Lisp Reference Manual}.
Regular expressions have a syntax in which a few characters are
special constructs and the rest are @dfn{ordinary}. An ordinary
You can also include character ranges in a character set, by writing the
starting and ending characters with a @samp{-} between them. Thus,
-@samp{[a-z]} matches any lower-case ASCII letter. Ranges may be
+@samp{[a-z]} matches any lower-case @acronym{ASCII} letter. Ranges may be
intermixed freely with individual characters, as in @samp{[a-z$%.]},
-which matches any lower-case ASCII letter or @samp{$}, @samp{%} or
+which matches any lower-case @acronym{ASCII} letter or @samp{$}, @samp{%} or
period.
Note that the usual regexp special characters are not special inside a
@item @kbd{[^ @dots{} ]}
@samp{[^} begins a @dfn{complemented character set}, which matches any
character except the ones specified. Thus, @samp{[^a-z0-9A-Z]} matches
-all characters @emph{except} ASCII letters and digits.
+all characters @emph{except} @acronym{ASCII} letters and digits.
@samp{^} is not special in a character set unless it is the first
character. The character following the @samp{^} is treated as if it
match anything. Thus, @samp{^foo} matches a @samp{foo} that occurs at
the beginning of a line.
+For historical compatibility reasons, @samp{^} can be used with this
+meaning only at the beginning of the regular expression, or after
+@samp{\(} or @samp{\|}.
+
@item @kbd{$}
is similar to @samp{^} but matches only at the end of a line. Thus,
@samp{x+$} matches a string of one @samp{x} or more at the end of a line.
+For historical compatibility reasons, @samp{$} can be used with this
+meaning only at the end of the regular expression, or before @samp{\)}
+or @samp{\|}.
+
@item @kbd{\}
has two functions: it quotes the special characters (including
@samp{\}), and it introduces additional special constructs.
@item \W
matches any character that is not a word-constituent.
+@item \_<
+matches the empty string, but only at the beginning of a symbol.
+A symbol is a sequence of one or more symbol-constituent characters.
+A symbol-constituent character is a character whose syntax is either
+@samp{w} or @samp{_}. @samp{\_<} matches at the beginning of the
+buffer only if a symbol-constituent character follows.
+
+@item \_>
+matches the empty string, but only at the end of a symbol. @samp{\_>}
+matches at the end of the buffer only if the contents end with a
+symbol-constituent character.
+
@item \s@var{c}
matches any character whose syntax is @var{c}. Here @var{c} is a
character that designates a particular syntax class: thus, @samp{w}
The constructs that pertain to words and syntax are controlled by the
setting of the syntax table (@pxref{Syntax}).
- Here is a complicated regexp, stored in @code{sentence-end} and used
-by Emacs to recognize the end of a sentence together with any
-whitespace that follows. We show its Lisp syntax to distinguish the
-spaces from the tab characters. In Lisp syntax, the string constant
-begins and ends with a double-quote. @samp{\"} stands for a
-double-quote as part of the regexp, @samp{\\} for a backslash as part
-of the regexp, @samp{\t} for a tab, and @samp{\n} for a newline.
+ Here is a complicated regexp. It is a simplified version of the
+regexp that Emacs uses, by default, to recognize the end of a sentence
+together with any whitespace that follows. We show its Lisp syntax to
+distinguish the spaces from the tab characters. In Lisp syntax, the
+string constant begins and ends with a double-quote. @samp{\"} stands
+for a double-quote as part of the regexp, @samp{\\} for a backslash as
+part of the regexp, @samp{\t} for a tab, and @samp{\n} for a newline.
@example
"[.?!][]\"')]*\\($\\| $\\|\t\\| \\)[ \t\n]*"
for matching parens.)
@end ignore
-@node Search Case, Replace, Regexps, Search
+@node Search Case, Configuring Scrolling, Regexps, Search
@section Searching and Case
Incremental searches in Emacs normally ignore the case of the text
performed by the replace commands (@pxref{Replace}) and the minibuffer
history matching commands (@pxref{Minibuffer History}).
-@node Replace, Other Repeating Search, Search Case, Search
+@node Configuring Scrolling, Replace, Search Case, Search
+@section Configuring Scrolling
+@cindex scrolling in incremental search
+@vindex isearch-allow-scroll
+
+Scrolling, etc., during incremental search is enabled by setting the
+customizable variable @code{isearch-allow-scroll} to a non-@code{nil} value.
+
+@c See Subject: Info file: How do I get an itemized list without blank lines?
+@c Date: Sat, 12 Apr 2003 09:45:31 +0000 in gnu.emacs.help
+@subsection Standard scrolling commands
+Here is the list of commands which are configured by default to be
+``scrolling'' commands in an incremental search, together with their
+usual bindings:
+@subsubsection Commands which scroll the window:
+@table @asis
+@item @code{scroll-bar-toolkit-scroll} (@kbd{@key{vertical-scroll-bar}@key{mouse-1}} in X-Windows)
+@itemx @code{mac-handle-scroll-bar-event} (@kbd{@key{vertical-scroll-bar}@key{mouse-1}} on a Mac)
+@itemx @code{w32-handle-scroll-bar-event} (@kbd{@key{vertical-scroll-bar}@key{mouse-1}} in MS-Windows)
+@item @code{recenter} (@kbd{C-l}) @xref{Scrolling}.
+@itemx @code{reposition-window} (@kbd{C-M-l}) @xref{Scrolling}.
+@itemx @code{scroll-up} (@kbd{@key{NEXT}}) @xref{Scrolling}.
+@itemx @code{scroll-down} (@kbd{@key{PRIOR}}) @xref{Scrolling}.
+@end table
+
+@subsubsection Commands which act on the other window:
+@table @asis
+@item @code{list-buffers} (@kbd{C-x C-b}) @xref{List Buffers}.
+@itemx @code{scroll-other-window} (@kbd{C-M-v}) @xref{Other Window}.
+@itemx @code{scroll-other-window-down} (@kbd{C-M-S-v}) @xref{Other Window}.
+@itemx @code{beginning-of-buffer-other-window} (@kbd{M-@key{home}})
+@itemx @code{end-of-buffer-other-window} (@kbd{M-@key{end}})
+@end table
+
+@subsubsection Commands which change the window layout:
+@table @asis
+@item @code{delete-other-windows} (@kbd{C-x 1}) @xref{Change Window}.
+@itemx @code{balance-windows} (@kbd{C-x +}) @xref{Change Window}.
+@itemx @code{split-window-vertically} (@kbd{C-x 2}) @xref{Split Window}.
+@itemx @code{enlarge-window} (@kbd{C-x ^}) @xref{Change Window}.
+@end table
+
+@subsection Configuring other commands as scrolling commands
+To do this, set a command's isearch-scroll property to the value t.
+For example:
+
+@example
+@code{(put 'my-command 'isearch-scroll t)}
+@end example
+
+You should only thus configure commands which are ``safe'': i.e., they
+won't leave emacs in an inconsistent state when executed within a
+search---that is to say, the following things may be changed by a
+command only temporarily, and must be restored before the command
+finishes:
+
+@enumerate
+@item
+Point.
+@item
+The buffer contents.
+@item
+The selected window and selected frame.
+@item
+The current match-data. @xref{Match Data,,, elisp, The Emacs Lisp
+Reference Manual}.
+@end enumerate
+
+Additionally, the command must not delete the current window and must
+not itself attempt an incremental search. It may, however, change the
+window's size, or create or delete other windows and frames.
+
+Note that an attempt by a command to scroll the text
+@emph{horizontally} won't work, although it will do no harm---any such
+scrolling will be overridden and nullified by the display code.
+
+@node Replace, Other Repeating Search, Configuring Scrolling, Search
@section Replacement Commands
@cindex replacement
@cindex search-and-replace commands
Global search-and-replace operations are not needed often in Emacs,
but they are available. In addition to the simple @kbd{M-x
-replace-string} command which is like that found in most editors,
+replace-string} command which replaces all occurrences,
there is a @kbd{M-x query-replace} command which finds each occurrence
of the pattern and asks you whether to replace it.
(@pxref{Expanding Abbrevs}).
@menu
-* Unconditional Replace:: Replacing all matches for a string.
-* Regexp Replace:: Replacing all matches for a regexp.
-* Replacement and Case:: How replacements preserve case of letters.
-* Query Replace:: How to use querying.
+* Unconditional Replace:: Replacing all matches for a string.
+* Regexp Replace:: Replacing all matches for a regexp.
+* Replacement and Case:: How replacements preserve case of letters.
+* Query Replace:: How to use querying.
@end menu
@node Unconditional Replace, Regexp Replace, Replace, Replace
What if you want to exchange @samp{x} and @samp{y}: replace every @samp{x} with a @samp{y} and vice versa? You can do it this way:
@example
-M-x query-replace @key{RET} x @key{RET} @@TEMP@@ @key{RET}
-M-x query-replace @key{RET} y @key{RET} x @key{RET}
-M-x query-replace @key{RET} @@TEMP@@ @key{RET} y @key{RET}
+M-x replace-string @key{RET} x @key{RET} @@TEMP@@ @key{RET}
+M-< M-x replace-string @key{RET} y @key{RET} x @key{RET}
+M-< M-x replace-string @key{RET} @@TEMP@@ @key{RET} y @key{RET}
@end example
@noindent
single string. The similar command @kbd{M-x replace-regexp} replaces
any match for a specified pattern.
- In @code{replace-regexp}, the @var{newstring} need not be constant: it
-can refer to all or part of what is matched by the @var{regexp}.
-@samp{\&} in @var{newstring} stands for the entire match being replaced.
-@samp{\@var{d}} in @var{newstring}, where @var{d} is a digit, stands for
-whatever matched the @var{d}th parenthesized grouping in @var{regexp}.
-To include a @samp{\} in the text to replace with, you must enter
-@samp{\\}. For example,
+ In @code{replace-regexp}, the @var{newstring} need not be constant:
+it can refer to all or part of what is matched by the @var{regexp}.
+@samp{\&} in @var{newstring} stands for the entire match being
+replaced. @samp{\@var{d}} in @var{newstring}, where @var{d} is a
+digit, stands for whatever matched the @var{d}th parenthesized
+grouping in @var{regexp}. @samp{\#} refers to the count of
+replacements already made in this command, as a decimal number. In
+the first replacement, @samp{\#} stands for @samp{0}; in the second,
+for @samp{1}; and so on. For example,
@example
M-x replace-regexp @key{RET} c[ad]+r @key{RET} \&-safe @key{RET}
@end example
@noindent
-performs the inverse transformation.
+performs the inverse transformation. To include a @samp{\} in the
+text to replace with, you must enter @samp{\\}.
+
+ You can also use Lisp expressions to calculate parts of the
+replacement string. To do this, write @samp{\,} followed by the
+expression in the replacement string. Each replacement calculates the
+value of the expression and converts it to text without quoting (if
+it's a string, this means using the string's contents), and uses it in
+the replacement string in place of the expression itself. If the
+expression is a symbol, one space in the replacement string after the
+symbol name goes with the symbol name, so the value replaces them
+both.
+
+ Inside such an expression, you can use some special sequences.
+@samp{\&} and @samp{\@var{n}} refer here, as usual, to the entire
+match as a string, and to a submatch as a string. @var{n} may be
+multiple digits, and the value of @samp{\@var{n}} is @code{nil} if
+subexpression @var{n} did not match. You can also use @samp{\#&} and
+@samp{\#@var{n}} to refer to those matches as numbers (this is valid
+when the match or submatch has the form of a numeral). @samp{\#} here
+too stands for the number of already-completed replacements.
+
+ Repeating our example to exchange @samp{x} and @samp{y}, we can thus
+do it also this way:
+
+@example
+M-x replace-regexp @key{RET} \(x\)\|y @key{RET}
+\,(if \1 "y" "x") @key{RET}
+@end example
+
+ For computing replacement strings for @samp{\,}, the @code{format}
+function is often useful (@pxref{Formatting Strings,,, elisp, The Emacs
+Lisp Reference Manual}). For example, to add consecutively numbered
+strings like @samp{ABC00042} to columns 73 @w{to 80} (unless they are
+already occupied), you can use
+
+@example
+M-x replace-regexp @key{RET} ^.\@{0,72\@}$ @key{RET}
+\,(format "%-72sABC%05d" \& \#) @key{RET}
+@end example
+
+ If you want to enter part of the replacement string by hand each
+time, use @samp{\?} in the replacement string. Each replacement will
+ask you to edit the replacement string in the minibuffer, putting
+point where the @samp{\?} was. For example,
+
+@example
+M-x replace-regexp @key{RET} \\footnote@{ @key{RET}
+\&\\label@{fn:\#\?@} @key{RET}
+@end example
+
+@noindent
+will add labels starting with @samp{\label@{fn:0@}} to occurrences of
+@samp{\footnote@{}, but letting you edit each replacement before
+performing it. To number the labels starting at 1, use @samp{\,(1+
+\#)} instead of @samp{\#}.
@node Replacement and Case, Query Replace, Regexp Replace, Replace
@subsection Replace Commands and Case
@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. This works by
-popping the mark ring. Only one @kbd{^} in a row is meaningful, because
-only one previous replacement position is kept during @code{query-replace}.
+be an occurrence), in case you changed it by mistake or want to
+reexamine it.
@item C-r
to enter a recursive editing level, in case the occurrence needs to be
@kbd{o} and @kbd{C-o} display the match in another window; @kbd{C-o}
does not select it.
+Occur mode supports the @code{next-error} functionality described in
+in @ref{Compilation Mode}.
+
@item M-x list-matching-lines
Synonym for @kbd{M-x occur}.
(@pxref{Tags Search}) or through Dired @kbd{A} command
(@pxref{Operating on Files}), or ask the @code{grep} program to do it
(@pxref{Grep Searching}).
+
+@ignore
+ arch-tag: fd9d8e77-66af-491c-b212-d80999613e3e
+@end ignore