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 fancy
-replacement command called @code{query-replace} which asks interactively
-which occurrences to replace.
+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.
@menu
* Incremental Search:: Search happens as you type the string.
@kindex C-s
@findex isearch-forward
- @kbd{C-s} starts an incremental search. @kbd{C-s} reads characters from
-the keyboard and positions the cursor at the first occurrence of the
-characters that you have typed. If you type @kbd{C-s} and then @kbd{F},
-the cursor moves right after the first @samp{F}. Type an @kbd{O}, and see
-the cursor move to after the first @samp{FO}. After another @kbd{O}, the
-cursor is 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; at each step, the current search
-string is updated in the echo area.
+ @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 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 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
When you are satisfied with the place you have reached, you can type
@key{RET}, 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. @key{RET}
-is necessary only if the next command you want to type is a printing
-character, @key{DEL}, @key{RET}, or another control character that is
+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.
+@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}, or @kbd{M-s}).
+@kbd{C-y}, @kbd{M-y}, @kbd{M-r}, @kbd{M-s}, and some other
+meta-characters).
- Sometimes you search for @samp{FOO} and find it, but not the one you
+ 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.
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
-``accept what the search offered.'' Or you can type @kbd{C-g}, which
+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
@cindex searching for non-ASCII characters
@cindex input method, during incremental search
To search for non-ASCII characters, you must use an input method
-(@pxref{Input Methods}). If an input method is turned on in the
+(@pxref{Input Methods}). If an input method is enabled in the
current buffer when you start the search, you can use it while you
type the search string also. Emacs indicates that by including the
input method mnemonic in its prompt, like this:
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. Note that the input method you turn on
-during incremental search is turned on in the current buffer as well.
+name of the input method. The input method you enable during
+incremental search remains enabled in the current buffer afterwards.
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.
point, just as a forward search finds matches that begin after it.
The characters @kbd{C-y} and @kbd{C-w} can be used in incremental
-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 word after point as part of the search string,
-advancing point over that word. Another @kbd{C-s} to repeat the search
-will then search for a string including that word. @kbd{C-y} is similar
-to @kbd{C-w} but copies all the rest of the current line into the search
-string. Both @kbd{C-y} and @kbd{C-w} convert the text they copy to
-lower case if the search is currently not case-sensitive; this is so the
-search remains case-insensitive.
+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. 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.
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.
@vindex isearch-lazy-highlight-face
@cindex faces for highlighting search matches
- You can control how does the highlighting of matches look like by
-customizing the faces @code{isearch} (used for the current match) and
-@code{isearch-lazy-highlight-face} (used for the other matches).
+ You can control how this highlighting looks by customizing the faces
+@code{isearch} (used for the current match) and
+@code{isearch-lazy-highlight-face} (for all the other matches).
@vindex isearch-mode-map
To customize the special characters that incremental search understands,
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 gets outside of the text that is already
+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.
-Then Emacs redisplays the window in which the search was done, to show
+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.
+initially 1200. See @code{baud-rate} in @ref{Display Custom}.
@vindex search-slow-window-lines
The number of lines to use in slow terminal search display is controlled
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 gets an error.
-
- The way @kbd{C-s @key{RET}} works is that the @kbd{C-s} invokes
-incremental search, which is specially programmed to invoke nonincremental
-search if the argument you give it is empty. (Such an empty argument would
-otherwise be useless.) @kbd{C-r @key{RET}} also works this way.
-
- However, nonincremental searches performed using @kbd{C-s @key{RET}} do
-not call @code{search-forward} right away. The first thing done is to see
-if the next character is @kbd{C-w}, which requests a word search.
+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.
@ifinfo
@xref{Word Search}.
@end ifinfo
+@kbd{C-r @key{RET}} does likewise, for a reverse incremental search.
@findex search-forward
@findex search-backward
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 suitable key sequences
+historical reasons, and to avoid the need to find key sequences
for them.
@node Word Search, Regexp Search, Nonincremental Search, 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 between the 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,
@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. The feature that you
-can get to them via the incremental search commands exists for historical
-reasons, and to avoid the need to find suitable key sequences for them.
+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 suitable key sequences for them.
@node Regexp Search, Regexps, Word Search, Search
@section Regular Expression Search
@cindex regular expression
@cindex regexp
- A @dfn{regular expression} (@dfn{regexp}, for short) is a pattern that
-denotes a class of alternative strings to match, possibly infinitely
-many. In GNU Emacs, you can search for the next match for a regexp
-either incrementally or not.
+ 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.
@kindex C-M-s
@findex isearch-forward-regexp
@kindex C-M-r
@findex isearch-backward-regexp
Incremental search for a regexp is done by typing @kbd{C-M-s}
-(@code{isearch-forward-regexp}). 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. Invoking @kbd{C-s}
-with a prefix argument (its value does not matter) is another way to do
-a forward incremental regexp search. To search backward for a regexp,
-use @kbd{C-M-r} (@code{isearch-backward-regexp}), or @kbd{C-r} with a
-prefix argument.
+(@code{isearch-forward-regexp}), or by invoking @kbd{C-s} with a
+prefix argument (whose value does not matter). This command reads a
+search string incrementally just like @kbd{C-s}, but it treats the
+search string as a regexp rather than looking for an exact match
+against the text in the buffer. Each time you add text to the search
+string, you make the regexp longer, and the new regexp is searched
+for. To search backward for a regexp, use @kbd{C-M-r}
+(@code{isearch-backward-regexp}), or @kbd{C-r} with a prefix argument.
All of the control characters that do special things within an
ordinary incremental search have the same function in incremental regexp
@node Regexps, Search Case, Regexp Search, Search
@section Syntax of Regular Expressions
-@cindex regexp syntax
+@cindex syntax of regexps
Regular expressions have a syntax in which a few characters are
special constructs and the rest are @dfn{ordinary}. An ordinary
character and nothing else. The special characters are @samp{$},
@samp{^}, @samp{.}, @samp{*}, @samp{+}, @samp{?}, @samp{[}, @samp{]} and
@samp{\}. Any other character appearing in a regular expression is
-ordinary, unless a @samp{\} precedes it.
+ordinary, unless a @samp{\} precedes it. (When you use regular
+expressions in a Lisp program, each @samp{\} must be doubled, see the
+example near the end of this section.)
For example, @samp{f} is not a special character, so it is ordinary, and
therefore @samp{f} is a regular expression that matches the string
match), while @samp{ab*?} will match just @samp{a} (the shortest
valid match).
+Non-greedy operators match the shortest possible string starting at a
+given starting point; in a forward search, though, the earliest
+possible starting point for match is always the one chosen. Thus, if
+you search for @samp{a.*?$} 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.
+
@item \@{@var{n}\@}
is a postfix operator that specifies repetition @var{n} times---that
is, the preceding regular expression must match exactly @var{n} times
and @samp{-}.
To include @samp{^} in a set, put it anywhere but at the beginning of
-the set.
+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
@item [^ @dots{} ]
@samp{[^} begins a @dfn{complemented character set}, which matches any
character except the ones specified. Thus, @samp{[^a-z0-9A-Z]} matches
-all characters @emph{except} letters and digits.
+all characters @emph{except} ASCII letters and digits.
@samp{^} is not special in a character set unless it is the first
character. The character following the @samp{^} is treated as if it
match is recorded.
@item \`
-matches the empty string, but only at the beginning
-of the buffer or string being matched against.
+matches the empty string, but only at the beginning of the string or
+buffer (or its accessible portion) being matched against.
@item \'
-matches the empty string, but only at the end of
-the buffer or string being matched against.
+matches the empty string, but only at the end of the string or buffer
+(or its accessible portion) being matched against.
@item \=
matches the empty string, but only at point.
@item \s@var{c}
matches any character whose syntax is @var{c}. Here @var{c} is a
-character that represents a syntax code: thus, @samp{w} for word
-constituent, @samp{-} for whitespace, @samp{(} for open parenthesis,
-etc. Represent a character of whitespace (which can be a newline) by
-either @samp{-} or a space character.
+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}.
@item \S@var{c}
matches any character whose syntax is not @var{c}.
The constructs that pertain to words and syntax are controlled by the
setting of the syntax table (@pxref{Syntax}).
- Here is a complicated regexp, used by Emacs to recognize the end of a
-sentence together with any whitespace that follows. It is given in Lisp
-syntax to enable you to distinguish the spaces from the tab characters. In
-Lisp syntax, the string constant begins and ends with a double-quote.
-@samp{\"} stands for a double-quote as part of the regexp, @samp{\\} for a
-backslash as part of the regexp, @samp{\t} for a tab and @samp{\n} for a
-newline.
+ Here is a complicated regexp, stored in @code{sentence-end} and used
+by Emacs to recognize the end of a sentence together with any
+whitespace that follows. We show its Lisp syntax to distinguish the
+spaces from the tab characters. In Lisp syntax, the string constant
+begins and ends with a double-quote. @samp{\"} stands for a
+double-quote as part of the regexp, @samp{\\} for a backslash as part
+of the regexp, @samp{\t} for a tab, and @samp{\n} for a newline.
@example
-"[.?!][]\"')]*\\($\\|\t\\| \\)[ \t\n]*"
+"[.?!][]\"')]*\\($\\| $\\|\t\\| \\)[ \t\n]*"
@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 any number of times; an alternative in
-backslash-parentheses that matches end-of-line, a tab, or two spaces;
-and a character set matching whitespace characters, repeated any number
-of times.
-
- To enter the same regexp interactively, 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.
+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.
@ignore
@c I commented this out because it is missing vital information
@node Search Case, Replace, Regexps, Search
@section Searching and Case
-@vindex case-fold-search
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
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.
+
+@vindex 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
@cindex string substitution
@cindex global substitution
- Global search-and-replace operations are not needed as often in Emacs
-as they are in other editors@footnote{In some editors,
-search-and-replace operations are the only convenient way to make a
-single change in the text.}, but they are available. In addition to the
-simple @kbd{M-x replace-string} command which is like that found in most
-editors, there is a @kbd{M-x query-replace} command which asks you, for
-each occurrence of the pattern, whether to replace it.
+ Global search-and-replace operations are not needed often in Emacs,
+but they are available. In addition to the simple @kbd{M-x
+replace-string} command which is like that found in most editors,
+there is a @kbd{M-x query-replace} command which finds 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, when the mark is
-active, they operate on the region. The replace commands all 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; however, in Transient Mark mode (@pxref{Transient
+Mark}), when the mark is active, they operate on the region. The
+replace commands all 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}).
@menu
* Unconditional Replace:: Replacing all matches for a string.
@subsection Replace Commands and Case
If the first argument of a replace command is all lower case, the
-commands ignores case while searching for occurrences to
+command ignores case while searching for occurrences to
replace---provided @code{case-fold-search} is non-@code{nil}. If
@code{case-fold-search} is set to @code{nil}, case is always significant
in all searches.
@samp{bar}, not all of them, then you cannot use an ordinary
@code{replace-string}. 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. A numeric argument to
-@code{query-replace} tells it to consider only occurrences that are
-bounded by word-delimiter characters. This preserves case, just like
-@code{replace-string}, provided @code{case-replace} is non-@code{nil},
-as it normally is.
+occurrence and asks you whether to replace it. Aside from querying,
+@code{query-replace} works just like @code{replace-string}. It
+preserves case, like @code{replace-string}, provided
+@code{case-replace} is non-@code{nil}, as it normally is. A numeric
+argument means consider only occurrences that are bounded by
+word-delimiter characters.
@kindex C-M-%
@findex query-replace-regexp
- Aside from querying, @code{query-replace} works just like
-@code{replace-string}, and @code{query-replace-regexp} works just like
-@code{replace-regexp}. This command is run by @kbd{C-M-%}.
+ @kbd{C-M-%} performs regexp search and replace (@code{query-replace-regexp}).
- The things you can type when you are shown an occurrence of @var{string}
-or a match for @var{regexp} are:
+ The characters you can type when you are shown a match for the string
+or regexp are:
@ignore @c Not worth it.
@kindex SPC @r{(query-replace)}
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 non-@code{nil}.
-Aside from @code{occur}, all operate on the text from point to the end
-of the buffer, or on the active region in Transient Mark mode.
+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.
@findex list-matching-lines
@findex occur
+@findex multi-occur
+@findex multi-occur-by-filename-regexp
@findex how-many
@findex delete-non-matching-lines
@findex delete-matching-lines
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 to display @var{n} lines of context before and after each
-matching line.
+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.
+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.
@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.
+
+@item M-x multi-occur-by-filename-regexp @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 regexp on their filename.
+
@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. In Transient Mark mode, if the region is active, the
HCoop / bpt / emacs.git / blobdiff