[Emacs-diffs] Changes to search.texi

[Glenn Morris]

CVSROOT:        /sources/emacs
Module name:    emacs
Changes by:     Glenn Morris <gm>       07/09/06 04:48:32

Index: search.texi
===================================================================
RCS file: search.texi
diff -N search.texi
--- /dev/null   1 Jan 1970 00:00:00 -0000
+++ search.texi 6 Sep 2007 04:48:32 -0000       1.1
@@ -0,0 +1,1361 @@
address@hidden This is part of the Emacs manual.
address@hidden Copyright (C) 1985, 1986, 1987, 1993, 1994, 1995, 1997, 2000, 
2001, 2002,
address@hidden   2003, 2004, 2005, 2006, 2007 Free Software Foundation, Inc.
address@hidden See file emacs.texi for copying conditions.
address@hidden Search, Fixit, Display, Top
address@hidden Searching and Replacement
address@hidden searching
address@hidden finding strings within text
+
+  Like other editors, Emacs has commands for searching for occurrences of
+a string.  The principal search command is unusual in that it is
address@hidden; it begins to search before you have finished typing the
+search string.  There are also nonincremental search commands more like
+those of other editors.
+
+  Besides the usual @code{replace-string} command that finds all
+occurrences of one string and replaces them with another, Emacs has a
+more flexible replacement command called @code{query-replace}, which
+asks interactively which occurrences to replace.  There are also
+commands to find and operate on all matches for a pattern.
+
+  You can also search multiple files under control of a tags
+table (@pxref{Tags Search}) or through the Dired @kbd{A} command
+(@pxref{Operating on Files}), or ask the @code{grep} program to do it
+(@pxref{Grep Searching}).
+
+
address@hidden
+* 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.
+* Regexp Backslash::            Regular expression constructs starting with 
`\'.
+* Regexp Example::              A complex regular expression explained.
+* 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.
address@hidden menu
+
address@hidden Incremental Search
address@hidden Incremental Search
address@hidden incremental search
address@hidden isearch
+
+  An incremental search begins searching as soon as you type the first
+character of the search string.  As you type in the search string, Emacs
+shows you where the string (as you have typed it so far) would be
+found.  When you have typed enough characters to identify the place you
+want, you can stop.  Depending on what you plan to do next, you may or
+may not need to terminate the search explicitly with @key{RET}.
+
address@hidden @kbd
address@hidden C-s
+Incremental search forward (@code{isearch-forward}).
address@hidden C-r
+Incremental search backward (@code{isearch-backward}).
address@hidden table
+
address@hidden
+* 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.
+* Non-ASCII Isearch::   How to search for non-ASCII characters.
+* Isearch Yank::        Commands that grab text into the search string
+                          or else edit the search string.
+* Highlight Isearch::   Isearch highlights the other possible matches.
+* Isearch Scroll::      Scrolling during an incremental search.
+* Slow Isearch::        Incremental search features for slow terminals.
address@hidden menu
+
address@hidden Basic Isearch
address@hidden Basics of Incremental Search
+
address@hidden C-s
address@hidden isearch-forward
+  @kbd{C-s} starts a forward incremental search.  It reads characters
+from the keyboard, and moves point past the next occurrence of those
+characters.  If you type @kbd{C-s} and then @kbd{F}, that puts the
+cursor after the first @samp{F} (the first following the starting point, since
+this is a forward search).  Then if you type an @kbd{O}, you will see
+the cursor move to just after the first @samp{FO} (the @samp{F} in that
address@hidden may or may not be the first @samp{F}).  After another
address@hidden, the cursor moves to just after the first @samp{FOO} after the 
place
+where you started the search.  At each step, the buffer text that
+matches the search string is highlighted, if the terminal can do that;
+the current search string is always displayed in the echo area.
+
+  If you make a mistake in typing the search string, you can cancel
+characters with @key{DEL}.  Each @key{DEL} cancels the last character of
+search string.  This does not happen until Emacs is ready to read another
+input character; first it must either find, or fail to find, the character
+you want to erase.  If you do not want to wait for this to happen, use
address@hidden as described below.
+
+  When you are satisfied with the place you have reached, you can type
address@hidden, which stops searching, leaving the cursor where the search
+brought it.  Also, any command not specially meaningful in searches
+stops the searching and is then executed.  Thus, typing @kbd{C-a}
+would exit the search and then move to the beginning of the line.
address@hidden 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},
address@hidden, @kbd{M-y}, @kbd{M-r}, @kbd{M-c}, @kbd{M-e}, and some other
+meta-characters).
+
+  When you exit the incremental search, it sets the mark where point
address@hidden before the search.  That is convenient for moving back
+there.  In Transient Mark mode, incremental search sets the mark
+without activating it, and does so only if the mark is not already
+active.
+
address@hidden Repeat Isearch
address@hidden Repeating Incremental Search
+
+  Sometimes you search for @samp{FOO} and find one, but not the one you
+expected to find.  There was a second @samp{FOO} that you forgot
+about, before the one you were aiming for.  In this event, type
+another @kbd{C-s} to move to the next occurrence of the search string.
+You can repeat this any number of times.  If you overshoot, you can
+cancel some @kbd{C-s} characters with @key{DEL}.
+
+  After you exit a search, you can search for the same string again by
+typing just @kbd{C-s C-s}: the first @kbd{C-s} is the key that invokes
+incremental search, and the second @kbd{C-s} means ``search again.''
+
+  If a search is failing and you ask to repeat it by typing another
address@hidden, it starts again from the beginning of the buffer.
+Repeating a failing reverse search with @kbd{C-r} starts again from
+the end.  This is called @dfn{wrapping around}, and @samp{Wrapped}
+appears in the search prompt once this has happened.  If you keep on
+going past the original starting point of the search, it changes to
address@hidden, which means that you are revisiting matches that
+you have already seen.
+
+  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.  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.
+
+  You can change to searching backwards with @kbd{C-r}.  For instance,
+if you are searching forward but you realize you were looking for
+something above the starting point, you can do this.  Repeated
address@hidden keeps looking for more occurrences backwards.  A @kbd{C-s}
+starts going forwards again.  @kbd{C-r} in a search can be canceled
+with @key{DEL}.
+
address@hidden C-r
address@hidden isearch-backward
+  If you know initially that you want to search backwards, you can use
address@hidden instead of @kbd{C-s} to start the search, because @kbd{C-r}
+as a key runs a command (@code{isearch-backward}) to search backward.
+A backward search finds matches that end before the starting point,
+just as a forward search finds matches that begin after it.
+
address@hidden Error in Isearch
address@hidden Errors in Incremental Search
+
+  If your string is not found at all, the echo area says @samp{Failing
+I-Search}.  The cursor is after the place where Emacs found as much of your
+string as it could.  Thus, if you search for @samp{FOOT}, and there is no
address@hidden, you might see the cursor after the @samp{FOO} in @samp{FOOL}.
+At this point there are several things you can do.  If your string was
+mistyped, you can rub some of it out and correct it.  If you like the place
+you have found, you can type @key{RET} or some other Emacs command to
+remain there.  Or you can type @kbd{C-g}, which
+removes from the search string the characters that could not be found (the
address@hidden in @samp{FOOT}), leaving those that were found (the @samp{FOO} in
address@hidden).  A second @kbd{C-g} at that point cancels the search
+entirely, returning point to where it was when the search started.
+
address@hidden quitting (in search)
+  The @kbd{C-g} ``quit'' character does special things during searches;
+just what it does depends on the status of the search.  If the search has
+found what you specified and is waiting for input, @kbd{C-g} cancels the
+entire search.  The cursor moves back to where you started the search.  If
address@hidden is typed when there are characters in the search string that have
+not been found---because Emacs is still searching for them, or because it
+has failed to find them---then the search string characters which have not
+been found are discarded from the search string.  With them gone, the
+search is now successful and waiting for more input, so a second @kbd{C-g}
+will cancel the entire search.
+
address@hidden Special Isearch
address@hidden Special Input for Incremental Search
+
+  An upper-case letter in the search string makes the search
+case-sensitive.  If you delete the upper-case character from the search
+string, it ceases to have this effect.  @xref{Search Case}.
+
+  To search for a newline, type @kbd{C-j}.  To search for another
+control character, such as control-S or carriage return, you must quote
+it by typing @kbd{C-q} first.  This function of @kbd{C-q} is analogous
+to its use for insertion (@pxref{Inserting Text}): it causes the
+following character to be treated the way any ``ordinary'' character is
+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.
+
+  @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.  @xref{Query
+Replace}.
+
+  Entering @key{RET} when the search string is empty launches
+nonincremental search (@pxref{Nonincremental Search}).
+
address@hidden isearch-mode-map
+  To customize the special characters that incremental search understands,
+alter their bindings in the keymap @code{isearch-mode-map}.  For a list
+of bindings, look at the documentation of @code{isearch-mode} with
address@hidden f isearch-mode @key{RET}}.
+
address@hidden Non-ASCII Isearch
address@hidden Isearch for address@hidden Characters
address@hidden searching for address@hidden characters
address@hidden input method, during incremental search
+
+  To enter address@hidden characters in an incremental search,
+you can use @kbd{C-q} (see the previous section), but it is easier to
+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 in the search string also.  Emacs indicates that by including the
+input method mnemonic in its prompt, like this:
+
address@hidden
+I-search address@hidden:
address@hidden example
+
address@hidden
address@hidden isearch-toggle-input-method
address@hidden isearch-toggle-specified-input-method
+where @var{im} is the mnemonic of the active input method.
+
+  You can toggle (enable or disable) the input method while you type
+the search string with @kbd{C-\} (@code{isearch-toggle-input-method}).
+You can turn on a certain (non-default) input method with @kbd{C-^}
+(@code{isearch-toggle-specified-input-method}), which prompts for the
+name of the input method.  The input method you enable during
+incremental search remains enabled in the current buffer afterwards.
+
address@hidden Isearch Yank
address@hidden Isearch Yanking
+
+  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.
address@hidden copies the character or word after point as part of the
+search string, advancing point over it.  (The decision, whether to
+copy a character or a word, is heuristic.)  Another @kbd{C-s} to
+repeat the search will then search for a string including that
+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.  If point is already at the end
+of a line, it grabs the entire next line.  Both @kbd{C-y} and
address@hidden 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
address@hidden 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.
address@hidden in the echo area does the same.
address@hidden
+
address@hidden Highlight Isearch
address@hidden Lazy Search Highlighting
address@hidden lazy search highlighting
address@hidden isearch-lazy-highlight
+
+  When you pause for a little while during incremental search, it
+highlights all other possible matches for the search string.  This
+makes it easier to anticipate where you can get to by typing @kbd{C-s}
+or @kbd{C-r} to repeat the search.  The short delay before highlighting
+other matches helps indicate which match is the current one.
+If you don't like this feature, you can turn it off by setting
address@hidden to @code{nil}.
+
address@hidden faces for highlighting search matches
+  You can control how this highlighting looks by customizing the faces
address@hidden (used for the current match) and @code{lazy-highlight}
+(for all the other matches).
+
address@hidden Isearch Scroll
address@hidden Scrolling During Incremental Search
+
+  You can enable the use of vertical scrolling during incremental
+search (without exiting the search) by setting the customizable
+variable @code{isearch-allow-scroll} to a address@hidden value.  This
+applies to using the vertical scroll-bar and to certain keyboard
+commands such as @address@hidden (@code{scroll-down}),
address@hidden@key{NEXT}} (@code{scroll-up}) and @kbd{C-l} (@code{recenter}).
+You must run these commands via their key sequences to stay in the
+search---typing @kbd{M-x} will terminate the search.  You can give
+prefix arguments to these commands in the usual way.
+
+  This feature won't let you scroll the current match out of visibility,
+however.
+
+  The feature also affects some other commands, such as @kbd{C-x 2}
+(@code{split-window-vertically}) and @kbd{C-x ^}
+(@code{enlarge-window}) which don't exactly scroll but do affect where
+the text appears on the screen.  In general, it applies to any command
+whose name has a address@hidden @code{isearch-scroll} property.  So you
+can control which commands are affected by changing these properties.
+
+  For example, to make @kbd{C-h l} usable within an incremental search
+in all future Emacs sessions, use @kbd{C-h c} to find what command it
+runs.  (You type @kbd{C-h c C-h l}; it says @code{view-lossage}.)
+Then you can put the following line in your @file{.emacs} file
+(@pxref{Init File}):
+
address@hidden
+(put 'view-lossage 'isearch-scroll t)
address@hidden example
+
address@hidden
+This feature can be applied to any command that doesn't permanently
+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.
+
address@hidden Slow Isearch
address@hidden Slow Terminal Incremental Search
+
+  Incremental search on a slow terminal uses a modified style of display
+that is designed to take less time.  Instead of redisplaying the buffer at
+each place the search gets to, it creates a new single-line window and uses
+that to display the line that the search has found.  The single-line window
+comes into play as soon as point moves outside of the text that is already
+on the screen.
+
+  When you terminate the search, the single-line window is removed.
+Emacs then redisplays the window in which the search was done, to show
+its new position of point.
+
address@hidden search-slow-speed
+  The slow terminal style of display is used when the terminal baud rate is
+less than or equal to the value of the variable @code{search-slow-speed},
+initially 1200.  See also the discussion of the variable @code{baud-rate}
+(@pxref{baud-rate,, Customization of Display}).
+
address@hidden search-slow-window-lines
+  The number of lines to use in slow terminal search display is controlled
+by the variable @code{search-slow-window-lines}.  Its normal value is 1.
+
address@hidden Nonincremental Search
address@hidden Nonincremental Search
address@hidden nonincremental search
+
+  Emacs also has conventional nonincremental search commands, which require
+you to type the entire search string before searching begins.
+
address@hidden @kbd
address@hidden C-s @key{RET} @var{string} @key{RET}
+Search for @var{string}.
address@hidden C-r @key{RET} @var{string} @key{RET}
+Search backward for @var{string}.
address@hidden table
+
+  To do a nonincremental search, first type @kbd{C-s @key{RET}}.  This
+enters the minibuffer to read the search string; terminate the string
+with @key{RET}, and then the search takes place.  If the string is not
+found, the search command signals an error.
+
+  When you type @kbd{C-s @key{RET}}, the @kbd{C-s} invokes incremental
+search as usual.  That command is specially programmed to invoke
+nonincremental search, @code{search-forward}, if the string you
+specify is empty.  (Such an empty argument would otherwise be
+useless.)  But it does not call @code{search-forward} right away.  First
+it checks the next input character to see if is @kbd{C-w},
+which specifies a word search.
address@hidden
address@hidden Search}.
address@hidden ifnottex
address@hidden @key{RET}} does likewise, for a reverse incremental search.
+
address@hidden search-forward
address@hidden search-backward
+  Forward and backward nonincremental searches are implemented by the
+commands @code{search-forward} and @code{search-backward}.  These
+commands may be bound to keys in the usual manner.  The feature that you
+can get to them via the incremental search commands exists for
+historical reasons, and to avoid the need to find separate key sequences
+for them.
+
address@hidden Word Search
address@hidden Word Search
address@hidden word search
+
+  Word search searches for a sequence of words without regard to how the
+words are separated.  More precisely, you type a string of many words,
+using single spaces to separate them, and the string can be found even
+if there are multiple spaces, newlines, or other punctuation characters
+between these words.
+
+  Word search is useful for editing a printed document made with a text
+formatter.  If you edit while looking at the printed, formatted version,
+you can't tell where the line breaks are in the source file.  With word
+search, you can search without having to know them.
+
address@hidden @kbd
address@hidden C-s @key{RET} C-w @var{words} @key{RET}
+Search for @var{words}, ignoring details of punctuation.
address@hidden C-r @key{RET} C-w @var{words} @key{RET}
+Search backward for @var{words}, ignoring details of punctuation.
address@hidden table
+
+  Word search as a special case of nonincremental search is invoked
+with @kbd{C-s @key{RET} C-w}.  This is followed by the search string,
+which must always be terminated with @key{RET}.  Being nonincremental,
+this search does not start until the argument is terminated.  It works
+by constructing a regular expression and searching for that; see
address@hidden Search}.
+
+  Use @kbd{C-r @key{RET} C-w} to do backward word search.
+
+  You can also invoke word search with @kbd{C-s M-e C-w} or @kbd{C-r
+M-e C-w} followed by the search string and terminated with @key{RET},
address@hidden or @kbd{C-r}.  This puts word search into incremental mode
+where you can use all keys available for incremental search.  However,
+when you type more words in incremental word search, it will fail
+until you type complete words.
+
address@hidden word-search-forward
address@hidden word-search-backward
+  Forward and backward word searches are implemented by the commands
address@hidden and @code{word-search-backward}.  These
+commands may be bound to keys in the usual manner.  They are available
+via the incremental search commands both for historical reasons and
+to avoid the need to find separate key sequences for them.
+
address@hidden Regexp Search
address@hidden Regular Expression Search
address@hidden regular expression
address@hidden regexp
+
+  A @dfn{regular expression} (@dfn{regexp}, for short) is a pattern
+that denotes a class of alternative strings to match, possibly
+infinitely many.  GNU Emacs provides both incremental and
+nonincremental ways to search for a match for a regexp.  The syntax of
+regular expressions is explained in the following section.
+
address@hidden C-M-s
address@hidden isearch-forward-regexp
address@hidden C-M-r
address@hidden isearch-backward-regexp
+  Incremental search for a regexp is done by typing @kbd{C-M-s}
+(@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}), @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
+search.  Typing @kbd{C-s} or @kbd{C-r} immediately after starting the
+search retrieves the last incremental search regexp used; that is to
+say, incremental regexp and non-regexp searches have independent
+defaults.  They also have separate search rings that you can access with
address@hidden and @kbd{M-n}.
+
address@hidden 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
address@hidden to the desired regexp.
+
+  In some cases, adding characters to the regexp in an incremental regexp
+search can make the cursor move back and start again.  For example, if
+you have searched for @samp{foo} and you add @samp{\|bar}, the cursor
+backs up in case the first @samp{bar} precedes the first @samp{foo}.
+
+  Forward and backward regexp search are not symmetrical, because
+regexp matching in Emacs always operates forward, starting with the
+beginning of the regexp.  Thus, forward regexp search scans forward,
+trying a forward match at each possible starting position.  Backward
+regexp search scans backward, trying a forward match at each possible
+starting position.  These search methods are not mirror images.
+
address@hidden re-search-forward
address@hidden re-search-backward
+  Nonincremental search for a regexp is done by the functions
address@hidden and @code{re-search-backward}.  You can invoke
+these with @kbd{M-x}, or bind them to keys, or invoke them by way of
+incremental regexp search with @kbd{C-M-s @key{RET}} and @kbd{C-M-r
address@hidden
+
+  If you use the incremental regexp search commands with a prefix
+argument, they perform ordinary string search, like
address@hidden and @code{isearch-backward}.  @xref{Incremental
+Search}.
+
address@hidden Regexps
address@hidden Syntax of Regular Expressions
address@hidden syntax of regexps
+
+  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 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
+character is a simple regular expression which matches that same
+character and nothing else.  The special characters are @samp{$},
address@hidden, @samp{.}, @samp{*}, @samp{+}, @samp{?}, @samp{[}, and
address@hidden  The character @samp{]} is special if it ends a character
+alternative (see later).  The character @samp{-} is special inside a
+character alternative.  Any other character appearing in a regular
+expression is ordinary, unless a @samp{\} precedes it.  (When you use
+regular expressions in a Lisp program, each @samp{\} must be doubled,
+see the example near the end of this section.)
+
+  For example, @samp{f} is not a special character, so it is ordinary, and
+therefore @samp{f} is a regular expression that matches the string
address@hidden and no other string.  (It does @emph{not} match the string
address@hidden)  Likewise, @samp{o} is a regular expression that matches
+only @samp{o}.  (When case distinctions are being ignored, these regexps
+also match @samp{F} and @samp{O}, but we consider this a generalization
+of ``the same string,'' rather than an exception.)
+
+  Any two regular expressions @var{a} and @var{b} can be concatenated.  The
+result is a regular expression which matches a string if @var{a} matches
+some amount of the beginning of that string and @var{b} matches the rest of
+the address@hidden
+
+  As a simple example, we can concatenate the regular expressions @samp{f}
+and @samp{o} to get the regular expression @samp{fo}, which matches only
+the string @samp{fo}.  Still trivial.  To do something nontrivial, you
+need to use one of the special characters.  Here is a list of them.
+
address@hidden @asis
address@hidden @kbd{.}@: @r{(Period)}
+is a special character that matches any single character except a newline.
+Using concatenation, we can make regular expressions like @samp{a.b}, which
+matches any three-character string that begins with @samp{a} and ends with
address@hidden@refill
+
address@hidden @kbd{*}
+is not a construct by itself; it is a postfix operator that means to
+match the preceding regular expression repetitively as many times as
+possible.  Thus, @samp{o*} matches any number of @samp{o}s (including no
address@hidden).
+
address@hidden always applies to the @emph{smallest} possible preceding
+expression.  Thus, @samp{fo*} has a repeating @samp{o}, not a repeating
address@hidden  It matches @samp{f}, @samp{fo}, @samp{foo}, and so on.
+
+The matcher processes a @samp{*} construct by matching, immediately,
+as many repetitions as can be found.  Then it continues with the rest
+of the pattern.  If that fails, backtracking occurs, discarding some
+of the matches of the @samp{*}-modified construct in case that makes
+it possible to match the rest of the pattern.  For example, in matching
address@hidden against the string @samp{caaar}, the @samp{a*} first
+tries to match all three @samp{a}s; but the rest of the pattern is
address@hidden 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 address@hidden
+
address@hidden @kbd{+}
+is a postfix operator, similar to @samp{*} except that it must match
+the preceding expression at least once.  So, for example, @samp{ca+r}
+matches the strings @samp{car} and @samp{caaaar} but not the string
address@hidden, whereas @samp{ca*r} matches all three strings.
+
address@hidden @kbd{?}
+is a postfix operator, similar to @samp{*} except that it can match the
+preceding expression either once or not at all.  For example,
address@hidden matches @samp{car} or @samp{cr}; nothing else.
+
address@hidden @kbd{*?}, @kbd{+?}, @kbd{??}
address@hidden non-greedy regexp matching
+are non-greedy variants of the operators above.  The normal operators
address@hidden, @samp{+}, @samp{?} are @dfn{greedy} in that they match as
+much as they can, as long as the overall regexp can still match.  With
+a following @samp{?}, they are non-greedy: they will match as little
+as possible.
+
+Thus, both @samp{ab*} and @samp{ab*?} can match the string @samp{a}
+and the string @samp{abbbb}; but if you try to match them both against
+the text @samp{abbb}, @samp{ab*} will match it all (the longest valid
+match), while @samp{ab*?}  will match just @samp{a} (the shortest
+valid match).
+
+Non-greedy operators match the shortest possible string starting at a
+given starting point; in a forward search, though, the earliest
+possible starting point for match is always the one chosen.  Thus, if
+you search for @samp{a.*?$} against the text @samp{abbab} followed by
+a newline, it matches the whole string.  Since it @emph{can} match
+starting at the first @samp{a}, it does.
+
address@hidden @address@hidden@address@hidden
+is a postfix operator that specifies repetition @var{n} times---that
+is, the preceding regular expression must match exactly @var{n} times
+in a row.  For example, @address@hidden@}} matches the string @samp{xxxx}
+and nothing else.
+
address@hidden @address@hidden@var{n},@address@hidden
+is a postfix operator that specifies repetition between @var{n} and
address@hidden times---that is, the preceding regular expression must match
+at least @var{n} times, but no more than @var{m} times.  If @var{m} is
+omitted, then there is no upper limit, but the preceding regular
+expression must match at least @var{n} address@hidden 
@address@hidden,address@hidden is
+equivalent to @samp{?}. @* @address@hidden,address@hidden is equivalent to
address@hidden @* @address@hidden,address@hidden is equivalent to @samp{+}.
+
address@hidden @kbd{[ @dots{} ]}
+is a @dfn{character set}, which begins with @samp{[} and is terminated
+by @samp{]}.  In the simplest case, the characters between the two
+brackets are what this set can match.
+
+Thus, @samp{[ad]} matches either one @samp{a} or one @samp{d}, and
address@hidden matches any string composed of just @samp{a}s and @samp{d}s
+(including the empty string), from which it follows that @samp{c[ad]*r}
+matches @samp{cr}, @samp{car}, @samp{cdr}, @samp{caddaar}, etc.
+
+You can also include character ranges in a character set, by writing the
+starting and ending characters with a @samp{-} between them.  Thus,
address@hidden matches any lower-case @acronym{ASCII} letter.  Ranges may be
+intermixed freely with individual characters, as in @samp{[a-z$%.]},
+which matches any lower-case @acronym{ASCII} letter or @samp{$}, @samp{%} or
+period.
+
+Note that the usual regexp special characters are not special inside a
+character set.  A completely different set of special characters exists
+inside character sets: @samp{]}, @samp{-} and @samp{^}.
+
+To include a @samp{]} in a character set, you must make it the first
+character.  For example, @samp{[]a]} matches @samp{]} or @samp{a}.  To
+include a @samp{-}, write @samp{-} as the first or last character of the
+set, or put it after a range.  Thus, @samp{[]-]} matches both @samp{]}
+and @samp{-}.
+
+To include @samp{^} in a set, put it anywhere but at the beginning of
+the set.  (At the beginning, it complements the set---see below.)
+
+When you use a range in case-insensitive search, you should write both
+ends of the range in upper case, or both in lower case, or both should
+be non-letters.  The behavior of a mixed-case range such as @samp{A-z}
+is somewhat ill-defined, and it may change in future Emacs versions.
+
address@hidden @kbd{[^ @dots{} ]}
address@hidden 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} @acronym{ASCII} letters and digits.
+
address@hidden is not special in a character set unless it is the first
+character.  The character following the @samp{^} is treated as if it
+were first (in other words, @samp{-} and @samp{]} are not special there).
+
+A complemented character set can match a newline, unless newline is
+mentioned as one of the characters not to match.  This is in contrast to
+the handling of regexps in programs such as @code{grep}.
+
address@hidden @kbd{^}
+is a special character that matches the empty string, but only at the
+beginning of a line in the text being matched.  Otherwise it fails to
+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
address@hidden(} or @samp{\|}.
+
address@hidden @kbd{$}
+is similar to @samp{^} but matches only at the end of a line.  Thus,
address@hidden matches a string of one @samp{x} or more at the end of a line.
+
+For historical compatibility reasons, @samp{$} can be used with this
+meaning only at the end of the regular expression, or before @samp{\)}
+or @samp{\|}.
+
address@hidden @kbd{\}
+has two functions: it quotes the special characters (including
address@hidden), and it introduces additional special constructs.
+
+Because @samp{\} quotes special characters, @samp{\$} is a regular
+expression that matches only @samp{$}, and @samp{\[} is a regular
+expression that matches only @samp{[}, and so on.
+
+See the following section for the special constructs that begin
+with @samp{\}.
address@hidden table
+
+  Note: for historical compatibility, special characters are treated as
+ordinary ones if they are in contexts where their special meanings make no
+sense.  For example, @samp{*foo} treats @samp{*} as ordinary since there is
+no preceding expression on which the @samp{*} can act.  It is poor practice
+to depend on this behavior; it is better to quote the special character anyway,
+regardless of where it appears.
+
+As a @samp{\} is not special inside a character alternative, it can
+never remove the special meaning of @samp{-} or @samp{]}.  So you
+should not quote these characters when they have no special meaning
+either.  This would not clarify anything, since backslashes can
+legitimately precede these characters where they @emph{have} special
+meaning, as in @samp{[^\]} (@code{"[^\\]"} for Lisp string syntax),
+which matches any single character except a backslash.
+
address@hidden Regexp Backslash
address@hidden Backslash in Regular Expressions
+
+  For the most part, @samp{\} followed by any character matches only
+that character.  However, there are several exceptions: two-character
+sequences starting with @samp{\} that have special meanings.  The
+second character in the sequence is always an ordinary character when
+used on its own.  Here is a table of @samp{\} constructs.
+
address@hidden @kbd
address@hidden \|
+specifies an alternative.  Two regular expressions @var{a} and @var{b}
+with @samp{\|} in between form an expression that matches some text if
+either @var{a} matches it or @var{b} matches it.  It works by trying to
+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 address@hidden
+
address@hidden|} applies to the largest possible surrounding expressions.  Only 
a
+surrounding @samp{\( @dots{} \)} grouping can limit the grouping power of
address@hidden|address@hidden
+
+Full backtracking capability exists to handle multiple uses of @samp{\|}.
+
address@hidden \( @dots{} \)
+is a grouping construct that serves three purposes:
+
address@hidden
address@hidden
+To enclose a set of @samp{\|} alternatives for other operations.
+Thus, @samp{\(foo\|bar\)x} matches either @samp{foox} or @samp{barx}.
+
address@hidden
+To enclose a complicated expression for the postfix operators @samp{*},
address@hidden and @samp{?} to operate on.  Thus, @samp{ba\(na\)*} matches
address@hidden, etc., with any (zero or more) number of @samp{na}
address@hidden
+
address@hidden
+To record a matched substring for future reference.
address@hidden enumerate
+
+This last application is not a consequence of the idea of a
+parenthetical grouping; it is a separate feature that is assigned as a
+second meaning to the same @samp{\( @dots{} \)} construct.  In practice
+there is usually no conflict between the two meanings; when there is
+a conflict, you can use a ``shy'' group.
+
address@hidden \(?: @dots{} \)
address@hidden shy group, in regexp
+specifies a ``shy'' group that does not record the matched substring;
+you can't refer back to it with @address@hidden  This is useful
+in mechanically combining regular expressions, so that you
+can add groups for syntactic purposes without interfering with
+the numbering of the groups that are meant to be referred to.
+
address@hidden address@hidden
address@hidden back reference, in regexp
+matches the same text that matched the @var{d}th occurrence of a
address@hidden( @dots{} \)} construct.  This is called a @dfn{back
+reference}.
+
+After the end of a @samp{\( @dots{} \)} construct, the matcher remembers
+the beginning and end of the text matched by that construct.  Then,
+later on in the regular expression, you can use @samp{\} followed by the
+digit @var{d} to mean ``match the same text matched the @var{d}th time
+by the @samp{\( @dots{} \)} construct.''
+
+The strings matching the first nine @samp{\( @dots{} \)} constructs
+appearing in a regular expression are assigned numbers 1 through 9 in
+the order that the open-parentheses appear in the regular expression.
+So you can use @samp{\1} through @samp{\9} to refer to the text matched
+by the corresponding @samp{\( @dots{} \)} constructs.
+
+For example, @samp{\(.*\)\1} matches any newline-free string that is
+composed of two identical halves.  The @samp{\(.*\)} matches the first
+half, which may be anything, but the @samp{\1} that follows must match
+the same exact text.
+
+If a particular @samp{\( @dots{} \)} construct matches more than once
+(which can easily happen if it is followed by @samp{*}), only the last
+match is recorded.
+
address@hidden \`
+matches the empty string, but only at the beginning of the string or
+buffer (or its accessible portion) being matched against.
+
address@hidden \'
+matches the empty string, but only at the end of the string or buffer
+(or its accessible portion) being matched against.
+
address@hidden \=
+matches the empty string, but only at point.
+
address@hidden \b
+matches the empty string, but only at the beginning or
+end of a word.  Thus, @samp{\bfoo\b} matches any occurrence of
address@hidden as a separate word.  @samp{\bballs?\b} matches
address@hidden or @samp{balls} as a separate address@hidden
+
address@hidden matches at the beginning or end of the buffer
+regardless of what text appears next to it.
+
address@hidden \B
+matches the empty string, but @emph{not} at the beginning or
+end of a word.
+
address@hidden \<
+matches the empty string, but only at the beginning of a word.
address@hidden<} matches at the beginning of the buffer only if a
+word-constituent character follows.
+
address@hidden \>
+matches the empty string, but only at the end of a word.  @samp{\>}
+matches at the end of the buffer only if the contents end with a
+word-constituent character.
+
address@hidden \w
+matches any word-constituent character.  The syntax table
+determines which characters these are.  @xref{Syntax}.
+
address@hidden \W
+matches any character that is not a word-constituent.
+
address@hidden \_<
+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
address@hidden or @samp{_}.  @samp{\_<} matches at the beginning of the
+buffer only if a symbol-constituent character follows.
+
address@hidden \_>
+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.
+
address@hidden address@hidden
+matches any character whose syntax is @var{c}.  Here @var{c} is a
+character that designates a particular syntax class: thus, @samp{w}
+for word constituent, @samp{-} or @samp{ } for whitespace, @samp{.}
+for ordinary punctuation, etc.  @xref{Syntax}.
+
address@hidden address@hidden
+matches any character whose syntax is not @var{c}.
+
address@hidden categories of characters
address@hidden characters which belong to a specific language
address@hidden describe-categories
address@hidden address@hidden
+matches any character that belongs to the category @var{c}.  For
+example, @samp{\cc} matches Chinese characters, @samp{\cg} matches
+Greek characters, etc.  For the description of the known categories,
+type @kbd{M-x describe-categories @key{RET}}.
+
address@hidden address@hidden
+matches any character that does @emph{not} belong to category
address@hidden
address@hidden table
+
+  The constructs that pertain to words and syntax are controlled by the
+setting of the syntax table (@pxref{Syntax}).
+
address@hidden Regexp Example
address@hidden Regular Expression Example
+
+  Here is a complicated regexp---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.
+
address@hidden
+"[.?!][]\"')]*\\($\\| $\\|\t\\|  \\)[ \t\n]*"
address@hidden example
+
address@hidden
+This contains four parts in succession: a character set matching
+period, @samp{?}, or @samp{!}; a character set matching
+close-brackets, quotes, or parentheses, repeated zero or more times; a
+set of alternatives within backslash-parentheses that matches either
+end-of-line, a space at the end of a line, a tab, or two spaces; and a
+character set matching whitespace characters, repeated any number of
+times.
+
+  To enter the same regexp in incremental search, you would type
address@hidden to enter a tab, and @kbd{C-j} to enter a newline.  You would
+also type single backslashes as themselves, instead of doubling them
+for Lisp syntax.  In commands that use ordinary minibuffer input to
+read a regexp, you would quote the @kbd{C-j} by preceding it with a
address@hidden to prevent @kbd{C-j} from exiting the minibuffer.
+
address@hidden Search Case
address@hidden Searching and Case
+
+  Incremental searches in Emacs normally ignore the case of the text
+they are searching through, if you specify the text in lower case.
+Thus, if you specify searching for @samp{foo}, then @samp{Foo} and
address@hidden are also considered a match.  Regexps, and in particular
+character sets, are included: @samp{[ab]} would match @samp{a} or
address@hidden or @samp{b} or @address@hidden
+
+  An upper-case letter anywhere in the incremental search string makes
+the search case-sensitive.  Thus, searching for @samp{Foo} does not find
address@hidden or @samp{FOO}.  This applies to regular expression search as
+well as to string search.  The effect ceases if you delete the
+upper-case letter from the search string.
+
+  Typing @kbd{M-c} within an incremental search toggles the case
+sensitivity of that search.  The effect does not extend beyond the
+current incremental search to the next one, but it does override the
+effect of including an upper-case letter in the current search.
+
address@hidden case-fold-search
address@hidden default-case-fold-search
+  If you set the variable @code{case-fold-search} to @code{nil}, then
+all letters must match exactly, including case.  This is a per-buffer
+variable; altering the variable affects only the current buffer, but
+there is a default value in @code{default-case-fold-search} that you
+can also set.  @xref{Locals}.  This variable applies to nonincremental
+searches also, including those performed by the replace commands
+(@pxref{Replace}) and the minibuffer history matching commands
+(@pxref{Minibuffer History}).
+
+  Several related variables control case-sensitivity of searching and
+matching for specific commands or activities.  For instance,
address@hidden controls case sensitivity for
address@hidden  To find these variables, do @kbd{M-x
+apropos-variable @key{RET} case-fold-search @key{RET}}.
+
address@hidden Replace
address@hidden Replacement Commands
address@hidden replacement
address@hidden search-and-replace commands
address@hidden string substitution
address@hidden global substitution
+
+  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 replaces all occurrences,
+there is @kbd{M-%} (@code{query-replace}), which presents each occurrence
+of the pattern and asks you whether to replace it.
+
+  The replace commands normally operate on the text from point to the
+end of the buffer; however, in Transient Mark mode (@pxref{Transient
+Mark}), when the mark is active, they operate on the region.  The
+basic replace commands replace one string (or regexp) with one
+replacement string.  It is possible to perform several replacements in
+parallel using the command @code{expand-region-abbrevs}
+(@pxref{Expanding Abbrevs}).
+
address@hidden
+* 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.
address@hidden menu
+
address@hidden Unconditional Replace, Regexp Replace, Replace, Replace
address@hidden Unconditional Replacement
address@hidden replace-string
+
address@hidden @kbd
address@hidden M-x replace-string @key{RET} @var{string} @key{RET} 
@var{newstring} @key{RET}
+Replace every occurrence of @var{string} with @var{newstring}.
address@hidden table
+
+  To replace every instance of @samp{foo} after point with @samp{bar},
+use the command @kbd{M-x replace-string} with the two arguments
address@hidden and @samp{bar}.  Replacement happens only in the text after
+point, so if you want to cover the whole buffer you must go to the
+beginning first.  All occurrences up to the end of the buffer are
+replaced; to limit replacement to part of the buffer, narrow to that
+part of the buffer before doing the replacement (@pxref{Narrowing}).
+In Transient Mark mode, when the region is active, replacement is
+limited to the region (@pxref{Transient Mark}).
+
+  When @code{replace-string} exits, it leaves point at the last
+occurrence replaced.  It sets the mark to the prior position of point
+(where the @code{replace-string} command was issued); use @kbd{C-u
address@hidden to move back there.
+
+  A numeric argument restricts replacement to matches that are surrounded
+by word boundaries.  The argument's value doesn't matter.
+
+  @xref{Replacement and Case}, for details about case-sensitivity in
+replace commands.
+
+  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:
+
address@hidden
+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}
address@hidden example
+
address@hidden
+This works provided the string @samp{@@TEMP@@} does not appear
+in your text.
+
address@hidden Regexp Replace, Replacement and Case, Unconditional Replace, 
Replace
address@hidden Regexp Replacement
address@hidden replace-regexp
+
+  The @kbd{M-x replace-string} command replaces exact matches for a
+single string.  The similar command @kbd{M-x replace-regexp} replaces
+any match for a specified pattern.
+
address@hidden @kbd
address@hidden M-x replace-regexp @key{RET} @var{regexp} @key{RET} 
@var{newstring} @key{RET}
+Replace every match for @var{regexp} with @var{newstring}.
address@hidden table
+
address@hidden back reference, in regexp replacement
+  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}.
address@hidden&} in @var{newstring} stands for the entire match being
+replaced.  @address@hidden in @var{newstring}, where @var{d} is a
+digit, stands for whatever matched the @var{d}th parenthesized
+grouping in @var{regexp}.  (This is called a ``back reference.'')
address@hidden 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,
+
address@hidden
+M-x replace-regexp @key{RET} c[ad]+r @key{RET} \&-safe @key{RET}
address@hidden example
+
address@hidden
+replaces (for example) @samp{cadr} with @samp{cadr-safe} and @samp{cddr}
+with @samp{cddr-safe}.
+
address@hidden
+M-x replace-regexp @key{RET} \(c[ad]+r\)-safe @key{RET} \1 @key{RET}
address@hidden example
+
address@hidden
+performs the inverse transformation.  To include a @samp{\} in the
+text to replace with, you must enter @samp{\\}.
+
+  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.
+
+  The remainder of this subsection is intended for specialized tasks
+and requires knowledge of Lisp.  Most readers can skip it.
+
+  You can 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.
address@hidden&} and @address@hidden 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 @address@hidden is @code{nil} if
+subexpression @var{n} did not match.  You can also use @samp{\#&} and
address@hidden@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:
+
address@hidden
+M-x replace-regexp @key{RET} \(x\)\|y @key{RET}
+\,(if \1 "y" "x") @key{RET}
address@hidden 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
+
address@hidden
+M-x replace-regexp @key{RET} address@hidden,address@hidden @key{RET}
+\,(format "%-72sABC%05d" \& \#) @key{RET}
address@hidden example
+
address@hidden Replacement and Case, Query Replace, Regexp Replace, Replace
address@hidden Replace Commands and Case
+
+  If the first argument of a replace command is all lower case, the
+command ignores case while searching for occurrences to
+replace---provided @code{case-fold-search} is address@hidden  If
address@hidden is set to @code{nil}, case is always significant
+in all searches.
+
address@hidden case-replace
+  In addition, when the @var{newstring} argument is all or partly lower
+case, replacement commands try to preserve the case pattern of each
+occurrence.  Thus, the command
+
address@hidden
+M-x replace-string @key{RET} foo @key{RET} bar @key{RET}
address@hidden example
+
address@hidden
+replaces a lower case @samp{foo} with a lower case @samp{bar}, an
+all-caps @samp{FOO} with @samp{BAR}, and a capitalized @samp{Foo} with
address@hidden  (These three alternatives---lower case, all caps, and
+capitalized, are the only ones that @code{replace-string} can
+distinguish.)
+
+  If upper-case letters are used in the replacement string, they remain
+upper case every time that text is inserted.  If upper-case letters are
+used in the first argument, the second argument is always substituted
+exactly as given, with no case conversion.  Likewise, if either
address@hidden or @code{case-fold-search} is set to @code{nil},
+replacement is done without case conversion.
+
address@hidden Query Replace,, Replacement and Case, Replace
address@hidden Query Replace
address@hidden query replace
+
address@hidden @kbd
address@hidden M-% @var{string} @key{RET} @var{newstring} @key{RET}
address@hidden M-x query-replace @key{RET} @var{string} @key{RET} 
@var{newstring} @key{RET}
+Replace some occurrences of @var{string} with @var{newstring}.
address@hidden C-M-% @var{regexp} @key{RET} @var{newstring} @key{RET}
address@hidden M-x query-replace-regexp @key{RET} @var{regexp} @key{RET} 
@var{newstring} @key{RET}
+Replace some matches for @var{regexp} with @var{newstring}.
address@hidden table
+
address@hidden M-%
address@hidden query-replace
+  If you want to change only some of the occurrences of @samp{foo} to
address@hidden, not all of them, then you cannot use an ordinary
address@hidden  Instead, use @kbd{M-%} (@code{query-replace}).
+This command finds occurrences of @samp{foo} one by one, displays each
+occurrence and asks you whether to replace it.  Aside from querying,
address@hidden works just like @code{replace-string}.  It
+preserves case, like @code{replace-string}, provided
address@hidden is address@hidden, as it normally is
+(@pxref{Replacement and Case}).  A numeric argument means consider
+only occurrences that are bounded by word-delimiter characters.
+
address@hidden C-M-%
address@hidden query-replace-regexp
+  @kbd{C-M-%} performs regexp search and replace (@code{query-replace-regexp}).
+It works like @code{replace-regexp} except that it queries
+like @code{query-replace}.
+
address@hidden faces for highlighting query replace
+  These commands highlight the current match using the face
address@hidden  They highlight other matches using
address@hidden just like incremental search (@pxref{Incremental
+Search}).
+
+  The characters you can type when you are shown a match for the string
+or regexp are:
+
address@hidden @c Not worth it.
address@hidden SPC @r{(query-replace)}
address@hidden DEL @r{(query-replace)}
address@hidden , @r{(query-replace)}
address@hidden RET @r{(query-replace)}
address@hidden . @r{(query-replace)}
address@hidden ! @r{(query-replace)}
address@hidden ^ @r{(query-replace)}
address@hidden C-r @r{(query-replace)}
address@hidden C-w @r{(query-replace)}
address@hidden C-l @r{(query-replace)}
address@hidden ignore
+
address@hidden WideCommands
address@hidden @kbd
address@hidden @key{SPC}
+to replace the occurrence with @var{newstring}.
+
address@hidden @key{DEL}
+to skip to the next occurrence without replacing this one.
+
address@hidden , @r{(Comma)}
+to replace this occurrence and display the result.  You are then asked
+for another input character to say what to do next.  Since the
+replacement has already been made, @key{DEL} and @key{SPC} are
+equivalent in this situation; both move to the next occurrence.
+
+You can type @kbd{C-r} at this point (see below) to alter the replaced
+text.  You can also type @kbd{C-x u} to undo the replacement; this exits
+the @code{query-replace}, so if you want to do further replacement you
+must use @kbd{C-x @key{ESC} @key{ESC} @key{RET}} to restart
+(@pxref{Repetition}).
+
address@hidden @key{RET}
+to exit without doing any more replacements.
+
address@hidden .@: @r{(Period)}
+to replace this occurrence and then exit without searching for more
+occurrences.
+
address@hidden !
+to replace all remaining occurrences without asking again.
+
address@hidden ^
+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
+reexamine it.
+
address@hidden C-r
+to enter a recursive editing level, in case the occurrence needs to be
+edited rather than just replaced with @var{newstring}.  When you are
+done, exit the recursive editing level with @kbd{C-M-c} to proceed to
+the next occurrence.  @xref{Recursive Edit}.
+
address@hidden C-w
+to delete the occurrence, and then enter a recursive editing level as in
address@hidden  Use the recursive edit to insert text to replace the deleted
+occurrence of @var{string}.  When done, exit the recursive editing level
+with @kbd{C-M-c} to proceed to the next occurrence.
+
address@hidden e
+to edit the replacement string in the minibuffer.  When you exit the
+minibuffer by typing @key{RET}, the minibuffer contents replace the
+current occurrence of the pattern.  They also become the new
+replacement string for any further occurrences.
+
address@hidden C-l
+to redisplay the screen.  Then you must type another character to
+specify what to do with this occurrence.
+
address@hidden C-h
+to display a message summarizing these options.  Then you must type
+another character to specify what to do with this occurrence.
address@hidden table
+
+  Some other characters are aliases for the ones listed above: @kbd{y},
address@hidden and @kbd{q} are equivalent to @key{SPC}, @key{DEL} and
address@hidden
+
+  Aside from this, any other character exits the @code{query-replace},
+and is then reread as part of a key sequence.  Thus, if you type
address@hidden, it exits the @code{query-replace} and then kills to end of
+line.
+
+  To restart a @code{query-replace} once it is exited, use @kbd{C-x
address@hidden @key{ESC}}, which repeats the @code{query-replace} because it
+used the minibuffer to read its arguments.  @xref{Repetition, C-x ESC
+ESC}.
+
+  @xref{Operating on Files}, for the Dired @kbd{Q} command which
+performs query replace on selected files.  See also @ref{Transforming
+File Names}, for Dired commands to rename, copy, or link files by
+replacing regexp matches in file names.
+
address@hidden Other Repeating Search
address@hidden Other Search-and-Loop Commands
+
+  Here are some other commands that find matches for a regular
+expression.  They all ignore case in matching, if the pattern contains
+no upper-case letters and @code{case-fold-search} is address@hidden
+Aside from @code{occur} and its variants, all operate on the text from
+point to the end of the buffer, or on the active region in Transient
+Mark mode.
+
address@hidden list-matching-lines
address@hidden occur
address@hidden multi-occur
address@hidden multi-occur-in-matching-buffers
address@hidden how-many
address@hidden delete-non-matching-lines
address@hidden delete-matching-lines
address@hidden flush-lines
address@hidden keep-lines
+
address@hidden @kbd
address@hidden M-x occur @key{RET} @var{regexp} @key{RET}
+Display a list showing each line in the buffer that contains a match
+for @var{regexp}.  To limit the search to part of the buffer, narrow
+to that part (@pxref{Narrowing}).  A numeric argument @var{n}
+specifies that @var{n} lines of context are to be displayed before and
+after each matching line.  Currently, @code{occur} can not correctly
+handle multiline matches.
+
address@hidden RET @r{(Occur mode)}
address@hidden o @r{(Occur mode)}
address@hidden C-o @r{(Occur mode)}
+The buffer @samp{*Occur*} containing the output serves as a menu for
+finding the occurrences in their original context.  Click
address@hidden on an occurrence listed in @samp{*Occur*}, or position
+point there and type @key{RET}; this switches to the buffer that was
+searched and moves point to the original of the chosen occurrence.
address@hidden and @kbd{C-o} display the match in another window; @kbd{C-o}
+does not select it.
+
+After using @kbd{M-x occur}, you can use @code{next-error} to visit
+the occurrences found, one by one.  @ref{Compilation Mode}.
+
address@hidden M-x list-matching-lines
+Synonym for @kbd{M-x occur}.
+
address@hidden M-x multi-occur @key{RET} @var{buffers} @key{RET} @var{regexp} 
@key{RET}
+This function is just like @code{occur}, except it is able to search
+through multiple buffers.  It asks you to specify the buffer names one by one.
+
address@hidden M-x multi-occur-in-matching-buffers @key{RET} @var{bufregexp} 
@key{RET} @var{regexp} @key{RET}
+This function is similar to @code{multi-occur}, except the buffers to
+search are specified by a regular expression that matches visited
+file names.  With a prefix argument, it uses the regular expression to match
+buffer names instead.
+
address@hidden M-x how-many @key{RET} @var{regexp} @key{RET}
+Print the number of matches for @var{regexp} that exist in the buffer
+after point.  In Transient Mark mode, if the region is active, the
+command operates on the region instead.
+
address@hidden M-x flush-lines @key{RET} @var{regexp} @key{RET}
+This command deletes each line that contains a match for @var{regexp},
+operating on the text after point; it deletes the current line
+if it contains a match starting after point.  In Transient Mark mode,
+if the region is active, the command operates on the region instead;
+it deletes a line partially contained in the region if it contains a
+match entirely contained in the region.
+
+If a match is split across lines, @code{flush-lines} deletes all those
+lines.  It deletes the lines before starting to look for the next
+match; hence, it ignores a match starting on the same line at which
+another match ended.
+
address@hidden M-x keep-lines @key{RET} @var{regexp} @key{RET}
+This command deletes each line that @emph{does not} contain a match for
address@hidden, operating on the text after point; if point is not at the
+beginning of a line, it always keeps the current line.  In Transient
+Mark mode, if the region is active, the command operates on the region
+instead; it never deletes lines that are only partially contained in
+the region (a newline that ends a line counts as part of that line).
+
+If a match is split across lines, this command keeps all those lines.
address@hidden table
+
address@hidden
+   arch-tag: fd9d8e77-66af-491c-b212-d80999613e3e
address@hidden ignore