@c This is part of the Emacs manual.
-@c Copyright (C) 1985, 1986, 1987, 1993, 1994, 1995, 1997, 2000, 2001, 2002,
-@c 2003, 2004, 2005, 2006, 2007, 2008 Free Software Foundation, Inc.
+@c Copyright (C) 1985-1987, 1993-1995, 1997, 2000-2012
+@c Free Software Foundation, Inc.
@c See file emacs.texi for copying conditions.
-@node Search, Fixit, Display, Top
+@node Search
@chapter Searching and Replacement
@cindex searching
@cindex 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
-@dfn{incremental}; it begins to search before you have finished typing the
-search string. There are also nonincremental search commands more like
-those of other editors.
+ Like other editors, Emacs has commands to search for occurrences of
+a string. Emacs also has commands to replace occurrences of a string
+with a different string. There are also commands that do the same
+thing, but search for patterns instead of fixed strings.
- 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
+ You can also search multiple files under the 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}).
-
@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.
-* 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.
+* 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 `\'.
+* 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.
@end menu
@node Incremental Search
@cindex incremental search
@cindex 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}.
+ The principal search command in Emacs is @dfn{incremental}: it
+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}.
@table @kbd
@item C-s
* 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.
+* Isearch Minibuffer:: Incremental search of the minibuffer history.
@end menu
@node Basic Isearch
@subsection Basics of Incremental Search
+@table @kbd
+@item C-s
+Begin incremental search (@code{isearch-forward}).
+@item C-r
+Begin reverse incremental search (@code{isearch-backward}).
+@end table
+
@kindex C-s
@findex 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
-@samp{FO} may or may not be the first @samp{F}). After another
-@kbd{O}, 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
-@kbd{C-g} as described below.
-
- When you are satisfied with the place you have reached, you can type
-@key{RET}, which stops searching, leaving the cursor where the search
+ @kbd{C-s} (@code{isearch-forward}) starts a forward incremental
+search. It reads characters from the keyboard, and moves point just
+past the end of the next occurrence of those characters in the buffer.
+
+ For instance, if you type @kbd{C-s} and then @kbd{F}, that puts the
+cursor after the first @samp{F} that occurs in the buffer after the
+starting point. Then if you then type @kbd{O}, the cursor moves to
+just after the first @samp{FO}; the @samp{F} in that @samp{FO} might
+not be the first @samp{F} previously found. After another @kbd{O},
+the cursor moves to just after the first @samp{FOO}.
+
+@cindex faces for highlighting search matches
+ At each step, Emacs highlights the @dfn{current match}---the buffer
+text that matches the search string---using the @code{isearch} face
+(@pxref{Faces}). The current search string is also displayed in the
+echo area.
+
+ If you make a mistake typing the search string, type @key{DEL}.
+Each @key{DEL} cancels the last character of the search string.
+
+ When you are satisfied with the place you have reached, type
+@key{RET}. This 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.
+exits the search and then moves to the beginning of the line.
@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-c}, @kbd{M-e}, and some other
-meta-characters).
+@kbd{C-y}, @kbd{M-y}, @kbd{M-r}, @kbd{M-c}, @kbd{M-e}, and some others
+described below).
+
+ As a special exception, entering @key{RET} when the search string is
+empty launches nonincremental search (@pxref{Nonincremental Search}).
When you exit the incremental search, it adds the original value of
-point to the mark ring, without activating the mark. You can thus use
-@kbd{C-@key{SPC}} to return to where you were before beginning the
+point to the mark ring, without activating the mark; you can thus use
+@kbd{C-u C-@key{SPC}} to return to where you were before beginning the
search. @xref{Mark Ring}. It only does this if the mark was not
already active.
+@kindex C-r
+@findex isearch-backward
+ To search backwards, use @kbd{C-r} (@code{isearch-backward}) instead
+of @kbd{C-s} to start the search. A backward search finds matches
+that end before the starting point, just as a forward search finds
+matches that begin after it.
+
@node Repeat Isearch
@subsection 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}.
+ Suppose you search forward for @samp{FOO} and find a match, but not
+the one you expected to find: the @samp{FOO} you were aiming for
+occurs later in the buffer. 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}. Similarly, each @kbd{C-r} in a backward
+incremental search repeats the backward search.
+
+@cindex lazy search highlighting
+@vindex isearch-lazy-highlight
+ If you pause for a little while during incremental search, Emacs
+highlights all the other possible matches for the search string that
+are present on the screen. This helps you anticipate where you can
+get to by typing @kbd{C-s} or @kbd{C-r} to repeat the search. The
+other matches are highlighted differently from the current match,
+using the customizable face @code{lazy-highlight} (@pxref{Faces}). If
+you don't like this feature, you can disable it by setting
+@code{isearch-lazy-highlight} to @code{nil}.
+
+ After exiting 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''. Similarly, @kbd{C-r C-r} searches backward for the last
+search string. In determining the last search string, it doesn't
+matter whether the string was searched for with @kbd{C-s} or
+@kbd{C-r}.
- 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 you are searching forward but you realize you were looking for
+something before the starting point, type @kbd{C-r} to switch to a
+backward search, leaving the search string unchanged. Similarly,
+@kbd{C-s} in a backward search switches to a forward search.
If a search is failing and you ask to repeat it by typing another
@kbd{C-s}, it starts again from the beginning of the buffer.
@samp{Overwrapped}, which means that you are revisiting matches that
you have already seen.
+@cindex search ring
+@kindex M-n @r{(Incremental search)}
+@kindex M-p @r{(Incremental search)}
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
-@kbd{C-r} 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}.
+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.
-@kindex C-r
-@findex isearch-backward
- If you know initially that you want to search backwards, you can use
-@kbd{C-r} 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.
+@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
+@kbd{C-s} or @kbd{C-r} to finish editing the string and search for it.
@node Error in Isearch
@subsection 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
-@samp{FOOT}, 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
-@samp{T} in @samp{FOOT}), leaving those that were found (the @samp{FOO} in
+I-Search}, and the cursor moves past the place where Emacs found as
+much of your string as it could. Thus, if you search for @samp{FOOT},
+and there is no @samp{FOOT}, you might see the cursor after the
+@samp{FOO} in @samp{FOOL}. In the echo area, the part of the search
+string that failed to match is highlighted using the face
+@code{isearch-fail}.
+
+ At this point, there are several things you can do. If your string
+was mistyped, you can use @key{DEL} to erase some of it and correct
+it. If you like the place you have found, you can type @key{RET} to
+remain there. Or you can type @kbd{C-g}, which removes from the
+search string the characters that could not be found (the @samp{T} in
+@samp{FOOT}), leaving those that were found (the @samp{FOO} in
@samp{FOOT}). A second @kbd{C-g} at that point cancels the search
entirely, returning point to where it was when the search started.
@cindex 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
-@kbd{C-g} 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.
+@kindex C-g @r{(Incremental search)}
+ The quit command, @kbd{C-g}, 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, moving the cursor back to where you started
+the search. If @kbd{C-g} 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.
@node Special Isearch
@subsection 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}).
+ Some of the characters you type during incremental search have
+special effects.
-@vindex 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
-@kbd{C-h f isearch-mode @key{RET}}.
-
-@node Non-ASCII Isearch
-@subsection Isearch for Non-@acronym{ASCII} Characters
-@cindex searching for non-@acronym{ASCII} characters
-@cindex input method, during incremental search
-
- To enter non-@acronym{ASCII} 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:
+@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
+delete the upper-case character from the search string, it ceases to
+have this effect. @xref{Search Case}.
+
+ To search for a newline character, type @kbd{C-j}.
+
+ To search for other control characters, such as @key{control-S},
+quote it by typing @kbd{C-q} first (@pxref{Inserting Text}). To
+search for non-@acronym{ASCII} characters, you can either use
+@kbd{C-q} and enter its octal code, or 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. While typing the search string, you can toggle the input method
+with the command @kbd{C-\} (@code{isearch-toggle-input-method}). You
+can also turn on a non-default input method with @kbd{C-^}
+(@code{isearch-toggle-specified-input-method}), which prompts for the
+name of the input method. When an input method is active during
+incremental search, the search prompt includes the input method
+mnemonic, like this:
@example
I-search [@var{im}]:
@noindent
@findex isearch-toggle-input-method
@findex isearch-toggle-specified-input-method
-where @var{im} is the mnemonic of the active input method.
+where @var{im} is the mnemonic of the active input method. Any input
+method you enable during incremental search remains enabled in the
+current buffer afterwards.
- 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.
+@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}.
-@node Isearch Yank
-@subsection Isearch Yanking
+@kindex M-TAB @r{(Incremental search)}
+ Typing @kbd{M-@key{TAB}} in incremental search invokes
+@code{isearch-complete}, which attempts to complete the search string
+using the search ring as a list of completion alternatives.
+@xref{Completion}. In many operating systems, the @kbd{M-@key{TAB}}
+key sequence is captured by the window manager; you then need to
+rebind @code{isearch-complete} to another key sequence if you want to
+use it (@pxref{Rebinding}).
- 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
-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
-@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.
-@kbd{Mouse-2} in the echo area does the same.
-@xref{Yanking}.
-
-@node Highlight Isearch
-@subsection Lazy Search Highlighting
-@cindex lazy search highlighting
-@vindex isearch-lazy-highlight
+@vindex isearch-mode-map
+ When incremental search is active, you can type @kbd{C-h C-h} to
+access interactive help options, including a list of special key
+bindings. These key bindings are part of the keymap
+@code{isearch-mode-map} (@pxref{Keymaps}).
- 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
-@code{isearch-lazy-highlight} to @code{nil}.
+@node Isearch Yank
+@subsection Isearch Yanking
-@cindex faces for highlighting search matches
- You can control how this highlighting looks by customizing the faces
-@code{isearch} (used for the current match) and @code{lazy-highlight}
-(for all the other matches).
+@kindex C-y @r{(Incremental search)}
+@kindex M-y @r{(Incremental search)}
+@findex isearch-yank-kill
+@findex isearch-yank-pop
+ Within incremental search, @kbd{C-y} (@code{isearch-yank-kill})
+appends the current kill to the search string. @kbd{M-y}
+(@code{isearch-yank-pop}), if called after @kbd{C-y}, replaces that
+appended text with an earlier kill, similar to the usual @kbd{M-y}
+(@code{yank-pop}) command (@pxref{Yanking}). @kbd{Mouse-2} appends
+the current X selection (@pxref{Primary Selection}).
+
+@kindex C-w @r{(Incremental search)}
+@findex isearch-yank-word-or-char
+ @kbd{C-w} (@code{isearch-yank-word-or-char}) appends the next
+character or word at point to the search string. This is an easy way
+to search for another occurrence of the text at point. (The decision
+of whether to copy a character or a word is heuristic.)
+
+@kindex M-s C-e @r{(Incremental search)}
+@findex isearch-yank-line
+ Similarly, @kbd{M-s C-e} (@code{isearch-yank-line}) appends the rest
+of the current line to the search string. If point is already at the
+end of a line, it appends the next line.
+
+ If the search is currently case-insensitive, both @kbd{C-w} and
+@kbd{M-s C-e} convert the text they copy to lower case, so that the
+search remains case-insensitive.
+
+@kindex C-M-w @r{(Incremental search)}
+@kindex C-M-y @r{(Incremental search)}
+@findex isearch-del-char
+@findex isearch-yank-char
+ @kbd{C-M-w} (@code{isearch-del-char}) deletes the last character
+from the search string, and @kbd{C-M-y} (@code{isearch-yank-char})
+appends the character after point to the search string. An
+alternative method to add the character after point is to enter the
+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
- 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 non-@code{nil} value. This
-applies to using the vertical scroll-bar and to certain keyboard
-commands such as @kbd{@key{PRIOR}} (@code{scroll-down}),
-@kbd{@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 non-@code{nil} @code{isearch-scroll} property. So you
-can control which commands are affected by changing these properties.
+@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,
+that enables the use of the scroll-bar, as well as keyboard scrolling
+commands like @kbd{C-v}, @kbd{M-v}, and @kbd{C-l} (@pxref{Scrolling}).
+This applies only to calling these commands via their bound key
+sequences---typing @kbd{M-x} will still exit 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 @code{isearch-allow-scroll} feature also affects some other
+commands, such as @kbd{C-x 2} (@code{split-window-below}) and @kbd{C-x
+^} (@code{enlarge-window}), which don't exactly scroll but do affect
+where the text appears on the screen. It applies to any command whose
+name has a non-@code{nil} @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}):
+runs (@pxref{Key Help}), which is @code{view-lossage}. Then you can
+put the following line in your init file (@pxref{Init File}):
@example
(put 'view-lossage 'isearch-scroll t)
or the selected window and frame. The command must not itself attempt
an incremental search.
-@node Slow Isearch
-@subsection 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.
-
-@vindex 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}).
-
-@vindex 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.
+@node Isearch Minibuffer
+@subsection Searching the Minibuffer
+@cindex minibuffer history, searching
+
+If you start an incremental search while the minibuffer is active,
+Emacs searches the contents of the minibuffer. Unlike searching an
+ordinary buffer, the search string is not shown in the echo area,
+because that is used to display the minibuffer.
+
+If an incremental search fails in the minibuffer, it tries searching
+the minibuffer history. @xref{Minibuffer History}. You can visualize
+the minibuffer and its history as a series of ``pages'', with the
+earliest history element on the first page and the current minibuffer
+on the last page. A forward search, @kbd{C-s}, searches forward to
+later pages; a reverse search, @kbd{C-r}, searches backwards to
+earlier pages. Like in ordinary buffer search, a failing search can
+wrap around, going from the last page to the first page or vice versa.
+
+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
+afterwards. Canceling the search, with @kbd{C-g}, restores the
+contents of the minibuffer when you began the search.
@node Nonincremental Search
@section Nonincremental Search
Search backward for @var{string}.
@end 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.
-@ifnottex
-@xref{Word Search}.
-@end ifnottex
-@kbd{C-r @key{RET}} does likewise, for a reverse incremental search.
+ To start 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.
@findex search-forward
@findex 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.
+ When you type @kbd{C-s @key{RET}}, the @kbd{C-s} invokes incremental
+search as usual. That command is specially programmed to invoke the
+command for nonincremental search, @code{search-forward}, if the
+string you specify is empty. (Such an empty argument would otherwise
+be useless.) @kbd{C-r @key{RET}} does likewise, invoking the command
+@code{search-backward}.
@node Word Search
@section Word Search
@cindex 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.
+ A @dfn{word search} finds a sequence of words without regard to the
+type of punctuation between them. For instance, if you enter a search
+string that consists of two words separated by a single space, the
+search matches any sequence of those two words separated by one or
+more spaces, newlines, or other punctuation characters. This is
+particularly useful for searching text documents, because you don't
+have to worry whether the words you are looking for are separated by
+newlines or spaces.
@table @kbd
-@item C-s @key{RET} C-w @var{words} @key{RET}
-Search for @var{words}, ignoring details of punctuation.
-@item C-r @key{RET} C-w @var{words} @key{RET}
-Search backward for @var{words}, ignoring details of punctuation.
+@item M-s w
+If incremental search is active, toggle word search mode
+(@code{isearch-toggle-word}); otherwise, begin an incremental forward
+word search (@code{isearch-forward-word}).
+@item M-s w @key{RET} @var{words} @key{RET}
+Search for @var{words}, using a forward nonincremental word search.
+@item M-s w C-r @key{RET} @var{words} @key{RET}
+Search backward for @var{words}, using a nonincremental word search.
@end 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
-@ref{Regexp 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},
-@kbd{C-s} 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.
+@kindex M-s w
+@findex isearch-forward-word
+ To begin a forward incremental word search, type @kbd{M-s w}. If
+incremental search is not already active, this runs the command
+@code{isearch-forward-word}. If incremental search is already active
+(whether a forward or backward search), @kbd{M-s w} switches to a word
+search while keeping the direction of the search and the current
+search string unchanged. You can toggle word search back off by
+typing @kbd{M-s w} again.
@findex word-search-forward
@findex word-search-backward
- Forward and backward word searches are implemented by the commands
-@code{word-search-forward} 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.
+ To begin a nonincremental word search, type @kbd{M-s w @key{RET}}
+for a forward search, or @kbd{M-s w C-r @key{RET}} for a backward search.
+These run the commands @code{word-search-forward} and
+@code{word-search-backward} respectively.
+
+ Incremental and nonincremental word searches differ slightly in the
+way they find a match. In a nonincremental word search, the last word
+in the search string must exactly match a whole word. In an
+incremental word search, the matching is more lax: the last word in
+the search string can match part of a word, so that the matching
+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 _ @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 _
+@findex isearch-forward-symbol
+ To begin a forward incremental symbol search, type @kbd{M-s _}. 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 regular expression
-@cindex regexp
+@cindex regexp search
+@cindex search for a regular expression
- 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.
+ A @dfn{regular expression} (or @dfn{regexp} for short) is a pattern
+that denotes a class of alternative strings to match. Emacs
+provides both incremental and nonincremental ways to search for a
+match for a regexp. The syntax of regular expressions is explained in
+the next section.
+
+@table @kbd
+@item C-M-s
+Begin incremental regexp search (@code{isearch-forward-regexp}).
+@item C-M-r
+Begin reverse incremental regexp search (@code{isearch-backward-regexp}).
+@end table
@kindex C-M-s
@findex isearch-forward-regexp
(@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
+ All of the special key sequences in an ordinary incremental search
+do similar things in an incremental regexp search. For instance,
+typing @kbd{C-s} immediately after starting the search retrieves the
+last incremental search regexp used and searches forward for it.
+Incremental regexp and non-regexp searches have independent defaults.
+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 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}.
+ 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}. @xref{Regexps}.
Forward and backward regexp search are not symmetrical, because
regexp matching in Emacs always operates forward, starting with the
@findex re-search-forward
@findex re-search-backward
- Nonincremental search for a regexp is done by the functions
-@code{re-search-forward} 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
-@key{RET}}.
+ Nonincremental search for a regexp is done with the commands
+@code{re-search-forward} and @code{re-search-backward}. You can
+invoke these with @kbd{M-x}, or by way of incremental regexp search
+with @kbd{C-M-s @key{RET}} and @kbd{C-M-r @key{RET}}.
If you use the incremental regexp search commands with a prefix
argument, they perform ordinary string search, like
@node Regexps
@section Syntax of Regular Expressions
@cindex syntax of regexps
+@cindex regular expression
+@cindex 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 Emacs Lisp Reference Manual}.
+typically use. @xref{Regular Expressions,,, elisp, The Emacs Lisp
+Reference Manual}, for additional features used mainly in Lisp
+programs.
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{$},
-@samp{^}, @samp{.}, @samp{*}, @samp{+}, @samp{?}, @samp{[}, and
-@samp{\}. The character @samp{]} is special if it ends a character
-alternative (see later). The character @samp{-} is special inside a
-character alternative. Any other character appearing in a regular
-expression is ordinary, unless a @samp{\} precedes it. (When you use
-regular expressions in a Lisp program, each @samp{\} must be doubled,
-see the example near the end of this section.)
+character matches that same character and nothing else. The special
+characters are @samp{$^.*+?[\}. 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
@samp{ff}.) 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 string.@refill
+of ``the same string'', rather than an exception.)
- 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.
+ 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 string. For example, concatenating the
+regular expressions @samp{f} and @samp{o} gives 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.
@table @asis
@item @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
-@samp{b}.@refill
+is a special character that matches any single character except a
+newline. For example, the regular expressions @samp{a.b} matches any
+three-character string that begins with @samp{a} and ends with
+@samp{b}.
@item @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
-@samp{o}s).
+match the preceding regular expression repetitively any number of
+times, as many times as possible. Thus, @samp{o*} matches any number
+of @samp{o}s, including no @samp{o}s.
@samp{*} always applies to the @emph{smallest} possible preceding
expression. Thus, @samp{fo*} has a repeating @samp{o}, not a repeating
@item @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
-@samp{cr}, whereas @samp{ca*r} matches all three strings.
+the preceding expression at least once. Thus, @samp{ca+r} matches the
+strings @samp{car} and @samp{caaaar} but not the string @samp{cr},
+whereas @samp{ca*r} matches all three strings.
@item @kbd{?}
-is a postfix operator, similar to @samp{*} except that it can match the
-preceding expression either once or not at all. For example,
-@samp{ca?r} matches @samp{car} or @samp{cr}; nothing else.
+is a postfix operator, similar to @samp{*} except that it can match
+the preceding expression either once or not at all. Thus, @samp{ca?r}
+matches @samp{car} or @samp{cr}, and nothing else.
@item @kbd{*?}, @kbd{+?}, @kbd{??}
@cindex non-greedy regexp matching
-are non-greedy variants of the operators above. The normal operators
-@samp{*}, @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.
+are non-@dfn{greedy} variants of the operators above. The normal
+operators @samp{*}, @samp{+}, @samp{?} match as much as they can, as
+long as the overall regexp can still match. With a following
+@samp{?}, 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
starting at the first @samp{a}, it does.
@item @kbd{\@{@var{n}\@}}
-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, @samp{x\@{4\@}} matches the string @samp{xxxx}
-and nothing else.
+is a postfix operator specifying @var{n} repetitions---that is, the
+preceding regular expression must match exactly @var{n} times in a
+row. For example, @samp{x\@{4\@}} matches the string @samp{xxxx} and
+nothing else.
@item @kbd{\@{@var{n},@var{m}\@}}
-is a postfix operator that specifies repetition between @var{n} and
-@var{m} 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
+is a postfix operator specifying between @var{n} and @var{m}
+repetitions---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} times.@* @samp{\@{0,1\@}} is
equivalent to @samp{?}. @* @samp{\@{0,\@}} is equivalent to
@samp{*}. @* @samp{\@{1,\@}} is equivalent to @samp{+}.
@item @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.
+is a @dfn{character set}, beginning with @samp{[} and terminated by
+@samp{]}.
-Thus, @samp{[ad]} matches either one @samp{a} or one @samp{d}, and
-@samp{[ad]*} 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.
+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 @samp{[ad]*} matches any string composed of just
+@samp{a}s and @samp{d}s (including the empty string). 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,
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{^}.
+You can also include certain special @dfn{character classes} in a
+character set. A @samp{[:} and balancing @samp{:]} enclose a
+character class inside a character alternative. For instance,
+@samp{[[:alnum:]]} matches any letter or digit. @xref{Char Classes,,,
+elisp, The Emacs Lisp Reference Manual}, for a list of character
+classes.
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
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.''
+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
word-constituent character.
@item \w
-matches any word-constituent character. The syntax table
-determines which characters these are. @xref{Syntax}.
+matches any word-constituent character. The syntax table determines
+which characters these are. @xref{Syntax Tables,, Syntax Tables,
+elisp, The Emacs Lisp Reference Manual}.
@item \W
matches any character that is not a word-constituent.
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}.
+for ordinary punctuation, etc. @xref{Syntax Tables,, Syntax Tables,
+elisp, The Emacs Lisp Reference Manual}.
@item \S@var{c}
matches any character whose syntax is not @var{c}.
@var{c}.
@end table
- The constructs that pertain to words and syntax are controlled by the
-setting of the syntax table (@pxref{Syntax}).
+ The constructs that pertain to words and syntax are controlled by
+the setting of the syntax table. @xref{Syntax Tables,, Syntax Tables,
+elisp, The Emacs Lisp Reference Manual}.
@node Regexp Example
@section 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.
+ Here is an example of a regexp---similar to the regexp that Emacs
+uses, by default, to recognize the end of a sentence, not including
+the following space (i.e., the variable @code{sentence-end-base}):
@example
-"[.?!][]\"')]*\\($\\| $\\|\t\\| \\)[ \t\n]*"
+@verbatim
+[.?!][]\"')}]*
+@end verbatim
@end example
@noindent
-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
-@key{TAB} 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
-@kbd{C-q} to prevent @kbd{C-j} from exiting the minibuffer.
+This contains two parts in succession: a character set matching
+period, @samp{?}, or @samp{!}, and a character set matching
+close-brackets, quotes, or parentheses, repeated zero or more times.
@node Search Case
@section 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
-@samp{foo} are also considered a match. Regexps, and in particular
-character sets, are included: @samp{[ab]} would match @samp{a} or
-@samp{A} or @samp{b} or @samp{B}.@refill
+ 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 @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
An upper-case letter anywhere in the incremental search string makes
the search case-sensitive. Thus, searching for @samp{Foo} does not find
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.
+effect of adding or removing an upper-case letter in the current
+search.
@vindex case-fold-search
-@vindex 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}).
+variable; altering the variable normally affects only the current buffer,
+unless you change its default value. @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,
@cindex string substitution
@cindex 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.
+ Emacs provides several commands for performing search-and-replace
+operations. In addition to the simple @kbd{M-x replace-string}
+command, 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. When the mark is active, they operate on the
-region instead (@pxref{Mark}). 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}).
+end of the buffer. When the region is active, they operate on it
+instead (@pxref{Mark}). The basic replace commands replace one
+@dfn{search string} (or regexp) with one @dfn{replacement string}. It
+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.
-* 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
+@node Unconditional Replace
@subsection Unconditional Replacement
@findex replace-string
@samp{foo} 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}).
-When the region is active, replacement is limited to the region
-(@pxref{Mark}).
+replaced; to limit replacement to part of the buffer, activate the
+region around that part. When the region is active, replacement is
+limited to the region (@pxref{Mark}).
When @code{replace-string} exits, it leaves point at the last
occurrence replaced. It adds the prior position of point (where the
activating the mark; use @kbd{C-u C-@key{SPC}} to move back there.
@xref{Mark Ring}.
- A numeric argument restricts replacement to matches that are surrounded
-by word boundaries. The argument's value doesn't matter.
+ A prefix argument restricts replacement to matches that are
+surrounded by word boundaries.
@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:
-
-@example
-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
-This works provided the string @samp{@@TEMP@@} does not appear
-in your text.
-
-@node Regexp Replace, Replacement and Case, Unconditional Replace, Replace
+@node Regexp Replace
@subsection Regexp Replacement
@findex replace-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}. (This is called a ``back reference.'')
+grouping in @var{regexp}. (This is called a ``back reference''.)
@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
\,(format "%-72sABC%05d" \& \#) @key{RET}
@end example
-@node Replacement and Case, Query Replace, Regexp Replace, Replace
+@node Replacement and Case
@subsection Replace Commands and Case
If the first argument of a replace command is all lower case, the
@code{case-replace} or @code{case-fold-search} is set to @code{nil},
replacement is done without case conversion.
-@node Query Replace,, Replacement and Case, Replace
+@node Query Replace
@subsection Query Replace
@cindex query replace
@table @kbd
@item M-% @var{string} @key{RET} @var{newstring} @key{RET}
-@itemx M-x query-replace @key{RET} @var{string} @key{RET} @var{newstring} @key{RET}
Replace some occurrences of @var{string} with @var{newstring}.
@item C-M-% @var{regexp} @key{RET} @var{newstring} @key{RET}
-@itemx M-x query-replace-regexp @key{RET} @var{regexp} @key{RET} @var{newstring} @key{RET}
Replace some matches for @var{regexp} with @var{newstring}.
@end table
@code{query-replace} works just like @code{replace-string}
(@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 consider
+(@pxref{Replacement and Case}). A numeric argument means to consider
only occurrences that are bounded by word-delimiter characters.
@kindex C-M-%
These commands highlight the current match using the face
@code{query-replace}. They highlight other matches using
@code{lazy-highlight} just like incremental search (@pxref{Incremental
-Search}). By default, @code{query-replace-regexp} will show
+Search}). By default, @code{query-replace-regexp} will show the
substituted replacement string for the current match in the
minibuffer. If you want to keep special sequences @samp{\&} and
@samp{\@var{n}} unexpanded, customize
@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
@findex multi-occur
@findex multi-occur-in-matching-buffers
@findex how-many
-@findex delete-non-matching-lines
-@findex delete-matching-lines
@findex flush-lines
@findex keep-lines
@table @kbd
-@item 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.
+@item M-x multi-isearch-buffers
+Prompt for one or more buffer names, ending with @key{RET}; then,
+begin a multi-buffer incremental search in those buffers. (If the
+search fails in one buffer, the next @kbd{C-s} tries searching the
+next specified buffer, and so forth.) With a prefix argument, prompt
+for a regexp and begin a multi-buffer incremental search in buffers
+matching that regexp.
+
+@item M-x multi-isearch-buffers-regexp
+This command is just like @code{multi-isearch-buffers}, except it
+performs an incremental regexp search.
+
+@cindex Occur mode
+@cindex mode, Occur
+@item M-x occur
+Prompt for a regexp, and display a list showing each line in the
+buffer that contains a match for it. 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.
@kindex RET @r{(Occur mode)}
@kindex o @r{(Occur mode)}
@kindex 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
-@kbd{Mouse-2} 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.
-@kbd{o} 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}.
-
-@item M-x list-matching-lines
-Synonym for @kbd{M-x occur}.
-
-@item 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.
-
-@item 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.
-
-@item 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. If the region is active, this operates on the region
-instead.
-
-@item 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. If the region is active, it
-operates on the region instead; if a line partially contained in the
-region contains a match entirely contained in the region, it is
-deleted.
+In the @file{*Occur*} buffer, you can click on each entry, or move
+point there and type @key{RET}, to visit the corresponding position in
+the buffer that was searched. @kbd{o} and @kbd{C-o} display the match
+in another window; @kbd{C-o} does not select it. Alternatively, you
+can use the @kbd{C-x `} (@code{next-error}) command to visit the
+occurrences one by one (@pxref{Compilation Mode}).
+
+@cindex Occur Edit mode
+@cindex mode, Occur Edit
+Typing @kbd{e} in the @file{*Occur*} buffer switches to Occur Edit
+mode, in which edits made to the entries are also applied to the text
+in the originating buffer. Type @kbd{C-c C-c} to return to Occur
+mode.
+
+The command @kbd{M-x list-matching-lines} is a synonym for @kbd{M-x
+occur}.
+
+@kindex M-s o
+@item M-s o
+Run @code{occur} using the search string of the last incremental
+string search. You can also run @kbd{M-s o} when an incremental
+search is active; this uses the current search string.
+
+@item M-x multi-occur
+This command 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.
+
+@item M-x multi-occur-in-matching-buffers
+This command 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.
+
+@item M-x how-many
+Prompt for a regexp, and print the number of matches for it in the
+buffer after point. If the region is active, this operates on the
+region instead.
+
+@item M-x flush-lines
+Prompt for a regexp, and delete each line that contains a match for
+it, operating on the text after point. This command deletes the
+current line if it contains a match starting after point. If the
+region is active, it operates on the region instead; if a line
+partially contained in the region contains a match entirely contained
+in the region, it is deleted.
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.
-@item M-x keep-lines @key{RET} @var{regexp} @key{RET}
-This command deletes each line that @emph{does not} contain a match
-for @var{regexp}, operating on the text after point; if point is not
-at the beginning of a line, it always keeps the current line. 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).
+@item M-x keep-lines
+Prompt for a regexp, and delete each line that @emph{does not} contain
+a match for it, operating on the text after point. If point is not at
+the beginning of a line, this command always keeps the current line.
+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.
@end table
-
-@ignore
- arch-tag: fd9d8e77-66af-491c-b212-d80999613e3e
-@end ignore