2 @c This is part of the GNU Emacs Lisp Reference Manual.
3 @c Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995, 1998 Free Software Foundation, Inc.
4 @c See the file elisp.texi for copying conditions.
5 @setfilename ../info/minibuf
6 @node Minibuffers, Command Loop, Read and Print, Top
8 @cindex arguments, reading
9 @cindex complex arguments
12 A @dfn{minibuffer} is a special buffer that Emacs commands use to read
13 arguments more complicated than the single numeric prefix argument.
14 These arguments include file names, buffer names, and command names (as
15 in @kbd{M-x}). The minibuffer is displayed on the bottom line of the
16 frame, in the same place as the echo area, but only while it is in use
17 for reading an argument.
20 * Intro to Minibuffers:: Basic information about minibuffers.
21 * Text from Minibuffer:: How to read a straight text string.
22 * Object from Minibuffer:: How to read a Lisp object or expression.
23 * Minibuffer History:: Recording previous minibuffer inputs
24 so the user can reuse them.
25 * Completion:: How to invoke and customize completion.
26 * Yes-or-No Queries:: Asking a question with a simple answer.
27 * Multiple Queries:: Asking a series of similar questions.
28 * Reading a Password:: Function for reading a password.
29 * Minibuffer Misc:: Various customization hooks and variables.
32 @node Intro to Minibuffers
33 @section Introduction to Minibuffers
35 In most ways, a minibuffer is a normal Emacs buffer. Most operations
36 @emph{within} a buffer, such as editing commands, work normally in a
37 minibuffer. However, many operations for managing buffers do not apply
38 to minibuffers. The name of a minibuffer always has the form @w{@samp{
39 *Minibuf-@var{number}}}, and it cannot be changed. Minibuffers are
40 displayed only in special windows used only for minibuffers; these
41 windows always appear at the bottom of a frame. (Sometimes frames have
42 no minibuffer window, and sometimes a special kind of frame contains
43 nothing but a minibuffer window; see @ref{Minibuffers and Frames}.)
45 The minibuffer's window is normally a single line. You can resize it
46 temporarily with the window sizing commands; it reverts to its normal
47 size when the minibuffer is exited. You can resize it permanently by
48 using the window sizing commands in the frame's other window, when the
49 minibuffer is not active. If the frame contains just a minibuffer, you
50 can change the minibuffer's size by changing the frame's size.
52 If a command uses a minibuffer while there is an active minibuffer,
53 this is called a @dfn{recursive minibuffer}. The first minibuffer is
54 named @w{@samp{ *Minibuf-0*}}. Recursive minibuffers are named by
55 incrementing the number at the end of the name. (The names begin with a
56 space so that they won't show up in normal buffer lists.) Of several
57 recursive minibuffers, the innermost (or most recently entered) is the
58 active minibuffer. We usually call this ``the'' minibuffer. You can
59 permit or forbid recursive minibuffers by setting the variable
60 @code{enable-recursive-minibuffers} or by putting properties of that
61 name on command symbols (@pxref{Minibuffer Misc}).
63 Like other buffers, a minibuffer may use any of several local keymaps
64 (@pxref{Keymaps}); these contain various exit commands and in some cases
65 completion commands (@pxref{Completion}).
69 @code{minibuffer-local-map} is for ordinary input (no completion).
72 @code{minibuffer-local-ns-map} is similar, except that @key{SPC} exits
73 just like @key{RET}. This is used mainly for Mocklisp compatibility.
76 @code{minibuffer-local-completion-map} is for permissive completion.
79 @code{minibuffer-local-must-match-map} is for strict completion and
80 for cautious completion.
83 @node Text from Minibuffer
84 @section Reading Text Strings with the Minibuffer
86 Most often, the minibuffer is used to read text as a string. It can
87 also be used to read a Lisp object in textual form. The most basic
88 primitive for minibuffer input is @code{read-from-minibuffer}; it can do
91 In most cases, you should not call minibuffer input functions in the
92 middle of a Lisp function. Instead, do all minibuffer input as part of
93 reading the arguments for a command, in the @code{interactive}
94 specification. @xref{Defining Commands}.
96 @defun read-from-minibuffer prompt-string &optional initial-contents keymap read hist default inherit-input-method
97 This function is the most general way to get input through the
98 minibuffer. By default, it accepts arbitrary text and returns it as a
99 string; however, if @var{read} is non-@code{nil}, then it uses
100 @code{read} to convert the text into a Lisp object (@pxref{Input
103 The first thing this function does is to activate a minibuffer and
104 display it with @var{prompt-string} as the prompt. This value must be a
105 string. Then the user can edit text in the minibuffer.
107 When the user types a command to exit the minibuffer,
108 @code{read-from-minibuffer} constructs the return value from the text in
109 the minibuffer. Normally it returns a string containing that text.
110 However, if @var{read} is non-@code{nil}, @code{read-from-minibuffer}
111 reads the text and returns the resulting Lisp object, unevaluated.
112 (@xref{Input Functions}, for information about reading.)
114 The argument @var{default} specifies a default value to make available
115 through the history commands. It should be a string, or @code{nil}. If
116 @var{read} is non-@code{nil}, then @var{default} is also used as the
117 input to @code{read}, if the user enters empty input. However, in the
118 usual case (where @var{read} is @code{nil}), @code{read-from-minibuffer}
119 does not return @var{default} when the user enters empty input; it
120 returns an empty string, @code{""}. In this respect, it is different
121 from all the other minibuffer input functions in this chapter.
123 If @var{keymap} is non-@code{nil}, that keymap is the local keymap to
124 use in the minibuffer. If @var{keymap} is omitted or @code{nil}, the
125 value of @code{minibuffer-local-map} is used as the keymap. Specifying
126 a keymap is the most important way to customize the minibuffer for
127 various applications such as completion.
129 The argument @var{hist} specifies which history list variable to use
130 for saving the input and for history commands used in the minibuffer.
131 It defaults to @code{minibuffer-history}. @xref{Minibuffer History}.
133 If the variable @code{minibuffer-allow-text-properties} is
134 non-@code{nil}, then the string which is returned includes whatever text
135 properties were present in the minibuffer. Otherwise all the text
136 properties are stripped when the value is returned.
138 If the argument @var{inherit-input-method} is non-@code{nil}, then the
139 minibuffer inherits the current input method (@pxref{Input Methods}) and
140 the setting of @code{enable-multibyte-characters} (@pxref{Text
141 Representations}) from whichever buffer was current before entering the
144 If @var{initial-contents} is a string, @code{read-from-minibuffer}
145 inserts it into the minibuffer, leaving point at the end, before the
146 user starts to edit the text. The minibuffer appears with this text as
147 its initial contents.
149 Alternatively, @var{initial-contents} can be a cons cell of the form
150 @code{(@var{string} . @var{position})}. This means to insert
151 @var{string} in the minibuffer but put point @var{position} characters
152 from the beginning, rather than at the end.
154 @strong{Usage note:} The @var{initial-contents} argument and the
155 @var{default} argument are two alternative features for more or less the
156 same job. It does not make sense to use both features in a single call
157 to @code{read-from-minibuffer}. In general, we recommend using
158 @var{default}, since this permits the user to insert the default value
159 when it is wanted, but does not burden the user with deleting it from
160 the minibuffer on other occasions.
163 @defun read-string prompt &optional initial history default inherit-input-method
164 This function reads a string from the minibuffer and returns it. The
165 arguments @var{prompt} and @var{initial} are used as in
166 @code{read-from-minibuffer}. The keymap used is
167 @code{minibuffer-local-map}.
169 The optional argument @var{history}, if non-nil, specifies a history
170 list and optionally the initial position in the list. The optional
171 argument @var{default} specifies a default value to return if the user
172 enters null input; it should be a string. The optional argument
173 @var{inherit-input-method} specifies whether to inherit the current
174 buffer's input method.
176 This function is a simplified interface to the
177 @code{read-from-minibuffer} function:
181 (read-string @var{prompt} @var{initial} @var{history} @var{default} @var{inherit})
184 (read-from-minibuffer @var{prompt} @var{initial} nil nil
185 @var{history} @var{default} @var{inherit})))
193 @defvar minibuffer-allow-text-properties
194 If this variable is @code{nil}, then @code{read-from-minibuffer} strips
195 all text properties from the minibuffer input before returning it.
196 Since all minibuffer input uses @code{read-from-minibuffer}, this
197 variable applies to all minibuffer input.
199 Note that the completion functions discard text properties unconditionally,
200 regardless of the value of this variable.
203 @defvar minibuffer-local-map
204 This is the default local keymap for reading from the minibuffer. By
205 default, it makes the following bindings:
209 @code{exit-minibuffer}
212 @code{exit-minibuffer}
215 @code{abort-recursive-edit}
218 @code{next-history-element}
221 @code{previous-history-element}
224 @code{next-matching-history-element}
227 @code{previous-matching-history-element}
231 @c In version 18, initial is required
233 @defun read-no-blanks-input prompt &optional initial inherit-input-method
234 This function reads a string from the minibuffer, but does not allow
235 whitespace characters as part of the input: instead, those characters
236 terminate the input. The arguments @var{prompt}, @var{initial}, and
237 @var{inherit-input-method} are used as in @code{read-from-minibuffer}.
239 This is a simplified interface to the @code{read-from-minibuffer}
240 function, and passes the value of the @code{minibuffer-local-ns-map}
241 keymap as the @var{keymap} argument for that function. Since the keymap
242 @code{minibuffer-local-ns-map} does not rebind @kbd{C-q}, it @emph{is}
243 possible to put a space into the string, by quoting it.
247 (read-no-blanks-input @var{prompt} @var{initial})
249 (read-from-minibuffer @var{prompt} @var{initial} minibuffer-local-ns-map)
254 @defvar minibuffer-local-ns-map
255 This built-in variable is the keymap used as the minibuffer local keymap
256 in the function @code{read-no-blanks-input}. By default, it makes the
257 following bindings, in addition to those of @code{minibuffer-local-map}:
261 @cindex @key{SPC} in minibuffer
262 @code{exit-minibuffer}
265 @cindex @key{TAB} in minibuffer
266 @code{exit-minibuffer}
269 @cindex @kbd{?} in minibuffer
270 @code{self-insert-and-exit}
274 @node Object from Minibuffer
275 @section Reading Lisp Objects with the Minibuffer
277 This section describes functions for reading Lisp objects with the
280 @defun read-minibuffer prompt &optional initial
281 This function reads a Lisp object using the minibuffer, and returns it
282 without evaluating it. The arguments @var{prompt} and @var{initial} are
283 used as in @code{read-from-minibuffer}.
285 This is a simplified interface to the
286 @code{read-from-minibuffer} function:
290 (read-minibuffer @var{prompt} @var{initial})
292 (read-from-minibuffer @var{prompt} @var{initial} nil t)
296 Here is an example in which we supply the string @code{"(testing)"} as
302 "Enter an expression: " (format "%s" '(testing)))
304 ;; @r{Here is how the minibuffer is displayed:}
308 ---------- Buffer: Minibuffer ----------
309 Enter an expression: (testing)@point{}
310 ---------- Buffer: Minibuffer ----------
315 The user can type @key{RET} immediately to use the initial input as a
316 default, or can edit the input.
319 @defun eval-minibuffer prompt &optional initial
320 This function reads a Lisp expression using the minibuffer, evaluates
321 it, then returns the result. The arguments @var{prompt} and
322 @var{initial} are used as in @code{read-from-minibuffer}.
324 This function simply evaluates the result of a call to
325 @code{read-minibuffer}:
329 (eval-minibuffer @var{prompt} @var{initial})
331 (eval (read-minibuffer @var{prompt} @var{initial}))
336 @defun edit-and-eval-command prompt form
337 This function reads a Lisp expression in the minibuffer, and then
338 evaluates it. The difference between this command and
339 @code{eval-minibuffer} is that here the initial @var{form} is not
340 optional and it is treated as a Lisp object to be converted to printed
341 representation rather than as a string of text. It is printed with
342 @code{prin1}, so if it is a string, double-quote characters (@samp{"})
343 appear in the initial text. @xref{Output Functions}.
345 The first thing @code{edit-and-eval-command} does is to activate the
346 minibuffer with @var{prompt} as the prompt. Then it inserts the printed
347 representation of @var{form} in the minibuffer, and lets the user edit it.
348 When the user exits the minibuffer, the edited text is read with
349 @code{read} and then evaluated. The resulting value becomes the value
350 of @code{edit-and-eval-command}.
352 In the following example, we offer the user an expression with initial
353 text which is a valid form already:
357 (edit-and-eval-command "Please edit: " '(forward-word 1))
359 ;; @r{After evaluation of the preceding expression,}
360 ;; @r{the following appears in the minibuffer:}
364 ---------- Buffer: Minibuffer ----------
365 Please edit: (forward-word 1)@point{}
366 ---------- Buffer: Minibuffer ----------
371 Typing @key{RET} right away would exit the minibuffer and evaluate the
372 expression, thus moving point forward one word.
373 @code{edit-and-eval-command} returns @code{nil} in this example.
376 @node Minibuffer History
377 @section Minibuffer History
378 @cindex minibuffer history
381 A @dfn{minibuffer history list} records previous minibuffer inputs so
382 the user can reuse them conveniently. A history list is actually a
383 symbol, not a list; it is a variable whose value is a list of strings
384 (previous inputs), most recent first.
386 There are many separate history lists, used for different kinds of
387 inputs. It's the Lisp programmer's job to specify the right history
388 list for each use of the minibuffer.
390 The basic minibuffer input functions @code{read-from-minibuffer} and
391 @code{completing-read} both accept an optional argument named @var{hist}
392 which is how you specify the history list. Here are the possible
397 Use @var{variable} (a symbol) as the history list.
399 @item (@var{variable} . @var{startpos})
400 Use @var{variable} (a symbol) as the history list, and assume that the
401 initial history position is @var{startpos} (an integer, counting from
402 zero which specifies the most recent element of the history).
404 If you specify @var{startpos}, then you should also specify that element
405 of the history as the initial minibuffer contents, for consistency.
408 If you don't specify @var{hist}, then the default history list
409 @code{minibuffer-history} is used. For other standard history lists,
410 see below. You can also create your own history list variable; just
411 initialize it to @code{nil} before the first use.
413 Both @code{read-from-minibuffer} and @code{completing-read} add new
414 elements to the history list automatically, and provide commands to
415 allow the user to reuse items on the list. The only thing your program
416 needs to do to use a history list is to initialize it and to pass its
417 name to the input functions when you wish. But it is safe to modify the
418 list by hand when the minibuffer input functions are not using it.
420 Here are some of the standard minibuffer history list variables:
422 @defvar minibuffer-history
423 The default history list for minibuffer history input.
426 @defvar query-replace-history
427 A history list for arguments to @code{query-replace} (and similar
428 arguments to other commands).
431 @defvar file-name-history
432 A history list for file-name arguments.
435 @defvar buffer-name-history
436 @tindex buffer-name-history
437 A history list for buffer-name arguments.
440 @defvar regexp-history
441 A history list for regular expression arguments.
444 @defvar extended-command-history
445 A history list for arguments that are names of extended commands.
448 @defvar shell-command-history
449 A history list for arguments that are shell commands.
452 @defvar read-expression-history
453 A history list for arguments that are Lisp expressions to evaluate.
460 @dfn{Completion} is a feature that fills in the rest of a name
461 starting from an abbreviation for it. Completion works by comparing the
462 user's input against a list of valid names and determining how much of
463 the name is determined uniquely by what the user has typed. For
464 example, when you type @kbd{C-x b} (@code{switch-to-buffer}) and then
465 type the first few letters of the name of the buffer to which you wish
466 to switch, and then type @key{TAB} (@code{minibuffer-complete}), Emacs
467 extends the name as far as it can.
469 Standard Emacs commands offer completion for names of symbols, files,
470 buffers, and processes; with the functions in this section, you can
471 implement completion for other kinds of names.
473 The @code{try-completion} function is the basic primitive for
474 completion: it returns the longest determined completion of a given
475 initial string, with a given set of strings to match against.
477 The function @code{completing-read} provides a higher-level interface
478 for completion. A call to @code{completing-read} specifies how to
479 determine the list of valid names. The function then activates the
480 minibuffer with a local keymap that binds a few keys to commands useful
481 for completion. Other functions provide convenient simple interfaces
482 for reading certain kinds of names with completion.
485 * Basic Completion:: Low-level functions for completing strings.
486 (These are too low level to use the minibuffer.)
487 * Minibuffer Completion:: Invoking the minibuffer with completion.
488 * Completion Commands:: Minibuffer commands that do completion.
489 * High-Level Completion:: Convenient special cases of completion
490 (reading buffer name, file name, etc.)
491 * Reading File Names:: Using completion to read file names.
492 * Programmed Completion:: Finding the completions for a given file name.
495 @node Basic Completion
496 @subsection Basic Completion Functions
498 The two functions @code{try-completion} and @code{all-completions}
499 have nothing in themselves to do with minibuffers. We describe them in
500 this chapter so as to keep them near the higher-level completion
501 features that do use the minibuffer.
503 @defun try-completion string collection &optional predicate
504 This function returns the longest common substring of all possible
505 completions of @var{string} in @var{collection}. The value of
506 @var{collection} must be an alist, an obarray, or a function that
507 implements a virtual set of strings (see below).
509 Completion compares @var{string} against each of the permissible
510 completions specified by @var{collection}; if the beginning of the
511 permissible completion equals @var{string}, it matches. If no permissible
512 completions match, @code{try-completion} returns @code{nil}. If only
513 one permissible completion matches, and the match is exact, then
514 @code{try-completion} returns @code{t}. Otherwise, the value is the
515 longest initial sequence common to all the permissible completions that
518 If @var{collection} is an alist (@pxref{Association Lists}), the
519 @sc{car}s of the alist elements form the set of permissible completions.
521 @cindex obarray in completion
522 If @var{collection} is an obarray (@pxref{Creating Symbols}), the names
523 of all symbols in the obarray form the set of permissible completions. The
524 global variable @code{obarray} holds an obarray containing the names of
525 all interned Lisp symbols.
527 Note that the only valid way to make a new obarray is to create it
528 empty and then add symbols to it one by one using @code{intern}.
529 Also, you cannot intern a given symbol in more than one obarray.
531 If the argument @var{predicate} is non-@code{nil}, then it must be a
532 function of one argument. It is used to test each possible match, and
533 the match is accepted only if @var{predicate} returns non-@code{nil}.
534 The argument given to @var{predicate} is either a cons cell from the alist
535 (the @sc{car} of which is a string) or else it is a symbol (@emph{not} a
536 symbol name) from the obarray.
538 You can also use a symbol that is a function as @var{collection}. Then
539 the function is solely responsible for performing completion;
540 @code{try-completion} returns whatever this function returns. The
541 function is called with three arguments: @var{string}, @var{predicate}
542 and @code{nil}. (The reason for the third argument is so that the same
543 function can be used in @code{all-completions} and do the appropriate
544 thing in either case.) @xref{Programmed Completion}.
546 In the first of the following examples, the string @samp{foo} is
547 matched by three of the alist @sc{car}s. All of the matches begin with
548 the characters @samp{fooba}, so that is the result. In the second
549 example, there is only one possible match, and it is exact, so the value
556 '(("foobar1" 1) ("barfoo" 2) ("foobaz" 3) ("foobar2" 4)))
561 (try-completion "foo" '(("barfoo" 2) ("foo" 3)))
566 In the following example, numerous symbols begin with the characters
567 @samp{forw}, and all of them begin with the word @samp{forward}. In
568 most of the symbols, this is followed with a @samp{-}, but not in all,
569 so no more than @samp{forward} can be completed.
573 (try-completion "forw" obarray)
578 Finally, in the following example, only two of the three possible
579 matches pass the predicate @code{test} (the string @samp{foobaz} is
580 too short). Both of those begin with the string @samp{foobar}.
585 (> (length (car s)) 6))
591 '(("foobar1" 1) ("barfoo" 2) ("foobaz" 3) ("foobar2" 4))
598 @defun all-completions string collection &optional predicate nospace
599 This function returns a list of all possible completions of
600 @var{string}. The arguments to this function are the same as those of
601 @code{try-completion}.
603 If @var{collection} is a function, it is called with three arguments:
604 @var{string}, @var{predicate} and @code{t}; then @code{all-completions}
605 returns whatever the function returns. @xref{Programmed Completion}.
607 If @var{nospace} is non-@code{nil}, completions that start with a space
608 are ignored unless @var{string} also starts with a space.
610 Here is an example, using the function @code{test} shown in the
611 example for @code{try-completion}:
616 (> (length (car s)) 6))
623 '(("foobar1" 1) ("barfoo" 2) ("foobaz" 3) ("foobar2" 4))
625 @result{} ("foobar1" "foobar2")
630 @defvar completion-ignore-case
631 If the value of this variable is
632 non-@code{nil}, Emacs does not consider case significant in completion.
635 @node Minibuffer Completion
636 @subsection Completion and the Minibuffer
638 This section describes the basic interface for reading from the
639 minibuffer with completion.
641 @defun completing-read prompt collection &optional predicate require-match initial hist default inherit-input-method
642 This function reads a string in the minibuffer, assisting the user by
643 providing completion. It activates the minibuffer with prompt
644 @var{prompt}, which must be a string.
646 The actual completion is done by passing @var{collection} and
647 @var{predicate} to the function @code{try-completion}. This happens in
648 certain commands bound in the local keymaps used for completion.
650 If @var{require-match} is @code{nil}, the exit commands work regardless
651 of the input in the minibuffer. If @var{require-match} is @code{t}, the
652 usual minibuffer exit commands won't exit unless the input completes to
653 an element of @var{collection}. If @var{require-match} is neither
654 @code{nil} nor @code{t}, then the exit commands won't exit unless the
655 input already in the buffer matches an element of @var{collection}.
657 However, empty input is always permitted, regardless of the value of
658 @var{require-match}; in that case, @code{completing-read} returns
659 @var{default}. The value of @var{default} (if non-@code{nil}) is also
660 available to the user through the history commands.
662 The user can exit with null input by typing @key{RET} with an empty
663 minibuffer. Then @code{completing-read} returns @code{""}. This is how
664 the user requests whatever default the command uses for the value being
665 read. The user can return using @key{RET} in this way regardless of the
666 value of @var{require-match}, and regardless of whether the empty string
667 is included in @var{collection}.
669 The function @code{completing-read} works by calling
670 @code{read-minibuffer}. It uses @code{minibuffer-local-completion-map}
671 as the keymap if @var{require-match} is @code{nil}, and uses
672 @code{minibuffer-local-must-match-map} if @var{require-match} is
673 non-@code{nil}. @xref{Completion Commands}.
675 The argument @var{hist} specifies which history list variable to use for
676 saving the input and for minibuffer history commands. It defaults to
677 @code{minibuffer-history}. @xref{Minibuffer History}.
679 If @var{initial} is non-@code{nil}, @code{completing-read} inserts it
680 into the minibuffer as part of the input. Then it allows the user to
681 edit the input, providing several commands to attempt completion.
682 In most cases, we recommend using @var{default}, and not @var{initial}.
684 If the argument @var{inherit-input-method} is non-@code{nil}, then the
685 minibuffer inherits the current input method (@pxref{Input
686 Methods}) and the setting of @code{enable-multibyte-characters}
687 (@pxref{Text Representations}) from whichever buffer was current before
688 entering the minibuffer.
690 Completion ignores case when comparing the input against the possible
691 matches, if the built-in variable @code{completion-ignore-case} is
692 non-@code{nil}. @xref{Basic Completion}.
694 Here's an example of using @code{completing-read}:
700 '(("foobar1" 1) ("barfoo" 2) ("foobaz" 3) ("foobar2" 4))
705 ;; @r{After evaluation of the preceding expression,}
706 ;; @r{the following appears in the minibuffer:}
708 ---------- Buffer: Minibuffer ----------
709 Complete a foo: fo@point{}
710 ---------- Buffer: Minibuffer ----------
715 If the user then types @kbd{@key{DEL} @key{DEL} b @key{RET}},
716 @code{completing-read} returns @code{barfoo}.
718 The @code{completing-read} function binds three variables to pass
719 information to the commands that actually do completion. These
720 variables are @code{minibuffer-completion-table},
721 @code{minibuffer-completion-predicate} and
722 @code{minibuffer-completion-confirm}. For more information about them,
723 see @ref{Completion Commands}.
726 @node Completion Commands
727 @subsection Minibuffer Commands That Do Completion
729 This section describes the keymaps, commands and user options used in
730 the minibuffer to do completion.
732 @defvar minibuffer-local-completion-map
733 @code{completing-read} uses this value as the local keymap when an
734 exact match of one of the completions is not required. By default, this
735 keymap makes the following bindings:
739 @code{minibuffer-completion-help}
742 @code{minibuffer-complete-word}
745 @code{minibuffer-complete}
749 with other characters bound as in @code{minibuffer-local-map}
750 (@pxref{Text from Minibuffer}).
753 @defvar minibuffer-local-must-match-map
754 @code{completing-read} uses this value as the local keymap when an
755 exact match of one of the completions is required. Therefore, no keys
756 are bound to @code{exit-minibuffer}, the command that exits the
757 minibuffer unconditionally. By default, this keymap makes the following
762 @code{minibuffer-completion-help}
765 @code{minibuffer-complete-word}
768 @code{minibuffer-complete}
771 @code{minibuffer-complete-and-exit}
774 @code{minibuffer-complete-and-exit}
778 with other characters bound as in @code{minibuffer-local-map}.
781 @defvar minibuffer-completion-table
782 The value of this variable is the alist or obarray used for completion
783 in the minibuffer. This is the global variable that contains what
784 @code{completing-read} passes to @code{try-completion}. It is used by
785 minibuffer completion commands such as @code{minibuffer-complete-word}.
788 @defvar minibuffer-completion-predicate
789 This variable's value is the predicate that @code{completing-read}
790 passes to @code{try-completion}. The variable is also used by the other
791 minibuffer completion functions.
794 @deffn Command minibuffer-complete-word
795 This function completes the minibuffer contents by at most a single
796 word. Even if the minibuffer contents have only one completion,
797 @code{minibuffer-complete-word} does not add any characters beyond the
798 first character that is not a word constituent. @xref{Syntax Tables}.
801 @deffn Command minibuffer-complete
802 This function completes the minibuffer contents as far as possible.
805 @deffn Command minibuffer-complete-and-exit
806 This function completes the minibuffer contents, and exits if
807 confirmation is not required, i.e., if
808 @code{minibuffer-completion-confirm} is @code{nil}. If confirmation
809 @emph{is} required, it is given by repeating this command
810 immediately---the command is programmed to work without confirmation
811 when run twice in succession.
814 @defvar minibuffer-completion-confirm
815 When the value of this variable is non-@code{nil}, Emacs asks for
816 confirmation of a completion before exiting the minibuffer. The
817 function @code{minibuffer-complete-and-exit} checks the value of this
818 variable before it exits.
821 @deffn Command minibuffer-completion-help
822 This function creates a list of the possible completions of the
823 current minibuffer contents. It works by calling @code{all-completions}
824 using the value of the variable @code{minibuffer-completion-table} as
825 the @var{collection} argument, and the value of
826 @code{minibuffer-completion-predicate} as the @var{predicate} argument.
827 The list of completions is displayed as text in a buffer named
828 @samp{*Completions*}.
831 @defun display-completion-list completions
832 This function displays @var{completions} to the stream in
833 @code{standard-output}, usually a buffer. (@xref{Read and Print}, for more
834 information about streams.) The argument @var{completions} is normally
835 a list of completions just returned by @code{all-completions}, but it
836 does not have to be. Each element may be a symbol or a string, either
837 of which is simply printed, or a list of two strings, which is printed
838 as if the strings were concatenated.
840 This function is called by @code{minibuffer-completion-help}. The
841 most common way to use it is together with
842 @code{with-output-to-temp-buffer}, like this:
845 (with-output-to-temp-buffer "*Completions*"
846 (display-completion-list
847 (all-completions (buffer-string) my-alist)))
851 @defopt completion-auto-help
852 If this variable is non-@code{nil}, the completion commands
853 automatically display a list of possible completions whenever nothing
854 can be completed because the next character is not uniquely determined.
857 @node High-Level Completion
858 @subsection High-Level Completion Functions
860 This section describes the higher-level convenient functions for
861 reading certain sorts of names with completion.
863 In most cases, you should not call these functions in the middle of a
864 Lisp function. When possible, do all minibuffer input as part of
865 reading the arguments for a command, in the @code{interactive}
866 specification. @xref{Defining Commands}.
868 @defun read-buffer prompt &optional default existing
869 This function reads the name of a buffer and returns it as a string.
870 The argument @var{default} is the default name to use, the value to
871 return if the user exits with an empty minibuffer. If non-@code{nil},
872 it should be a string or a buffer. It is mentioned in the prompt, but
873 is not inserted in the minibuffer as initial input.
875 If @var{existing} is non-@code{nil}, then the name specified must be
876 that of an existing buffer. The usual commands to exit the minibuffer
877 do not exit if the text is not valid, and @key{RET} does completion to
878 attempt to find a valid name. (However, @var{default} is not checked
879 for validity; it is returned, whatever it is, if the user exits with the
882 In the following example, the user enters @samp{minibuffer.t}, and
883 then types @key{RET}. The argument @var{existing} is @code{t}, and the
884 only buffer name starting with the given input is
885 @samp{minibuffer.texi}, so that name is the value.
888 (read-buffer "Buffer name? " "foo" t)
890 ;; @r{After evaluation of the preceding expression,}
891 ;; @r{the following prompt appears,}
892 ;; @r{with an empty minibuffer:}
896 ---------- Buffer: Minibuffer ----------
897 Buffer name? (default foo) @point{}
898 ---------- Buffer: Minibuffer ----------
902 ;; @r{The user types @kbd{minibuffer.t @key{RET}}.}
903 @result{} "minibuffer.texi"
908 @defvar read-buffer-function
909 This variable specifies how to read buffer names. For example, if you
910 set this variable to @code{iswitchb-read-buffer}, all Emacs commands
911 that call @code{read-buffer} to read a buffer name will actually use the
912 @code{iswitchb} package to read it.
915 @defun read-command prompt &optional default
916 This function reads the name of a command and returns it as a Lisp
917 symbol. The argument @var{prompt} is used as in
918 @code{read-from-minibuffer}. Recall that a command is anything for
919 which @code{commandp} returns @code{t}, and a command name is a symbol
920 for which @code{commandp} returns @code{t}. @xref{Interactive Call}.
922 The argument @var{default} specifies what to return if the user enters
923 null input. It can be a symbol or a string; if it is a string,
924 @code{read-command} interns it before returning it. If @var{default} is
925 @code{nil}, that means no default has been specified; then if the user
926 enters null input, the return value is @code{nil}.
929 (read-command "Command name? ")
932 ;; @r{After evaluation of the preceding expression,}
933 ;; @r{the following prompt appears with an empty minibuffer:}
937 ---------- Buffer: Minibuffer ----------
939 ---------- Buffer: Minibuffer ----------
944 If the user types @kbd{forward-c @key{RET}}, then this function returns
947 The @code{read-command} function is a simplified interface to
948 @code{completing-read}. It uses the variable @code{obarray} so as to
949 complete in the set of extant Lisp symbols, and it uses the
950 @code{commandp} predicate so as to accept only command names:
952 @cindex @code{commandp} example
955 (read-command @var{prompt})
957 (intern (completing-read @var{prompt} obarray
963 @defun read-variable prompt &optional default
964 This function reads the name of a user variable and returns it as a
967 The argument @var{default} specifies what to return if the user enters
968 null input. It can be a symbol or a string; if it is a string,
969 @code{read-variable} interns it before returning it. If @var{default}
970 is @code{nil}, that means no default has been specified; then if the
971 user enters null input, the return value is @code{nil}.
975 (read-variable "Variable name? ")
977 ;; @r{After evaluation of the preceding expression,}
978 ;; @r{the following prompt appears,}
979 ;; @r{with an empty minibuffer:}
983 ---------- Buffer: Minibuffer ----------
984 Variable name? @point{}
985 ---------- Buffer: Minibuffer ----------
990 If the user then types @kbd{fill-p @key{RET}}, @code{read-variable}
991 returns @code{fill-prefix}.
993 This function is similar to @code{read-command}, but uses the
994 predicate @code{user-variable-p} instead of @code{commandp}:
996 @cindex @code{user-variable-p} example
999 (read-variable @var{prompt})
1002 (completing-read @var{prompt} obarray
1003 'user-variable-p t nil))
1008 See also the functions @code{read-coding-system} and
1009 @code{read-non-nil-coding-system}, in @ref{User-Chosen Coding Systems}.
1011 @node Reading File Names
1012 @subsection Reading File Names
1014 Here is another high-level completion function, designed for reading a
1015 file name. It provides special features including automatic insertion
1016 of the default directory.
1018 @defun read-file-name prompt &optional directory default existing initial
1019 This function reads a file name in the minibuffer, prompting with
1020 @var{prompt} and providing completion. If @var{default} is
1021 non-@code{nil}, then the function returns @var{default} if the user just
1022 types @key{RET}. @var{default} is not checked for validity; it is
1023 returned, whatever it is, if the user exits with the minibuffer empty.
1025 If @var{existing} is non-@code{nil}, then the user must specify the name
1026 of an existing file; @key{RET} performs completion to make the name
1027 valid if possible, and then refuses to exit if it is not valid. If the
1028 value of @var{existing} is neither @code{nil} nor @code{t}, then
1029 @key{RET} also requires confirmation after completion. If
1030 @var{existing} is @code{nil}, then the name of a nonexistent file is
1033 The argument @var{directory} specifies the directory to use for
1034 completion of relative file names. If @code{insert-default-directory}
1035 is non-@code{nil}, @var{directory} is also inserted in the minibuffer as
1036 initial input. It defaults to the current buffer's value of
1037 @code{default-directory}.
1040 If you specify @var{initial}, that is an initial file name to insert in
1041 the buffer (after @var{directory}, if that is inserted). In this
1042 case, point goes at the beginning of @var{initial}. The default for
1043 @var{initial} is @code{nil}---don't insert any file name. To see what
1044 @var{initial} does, try the command @kbd{C-x C-v}. @strong{Note:} we
1045 recommend using @var{default} rather than @var{initial} in most cases.
1051 (read-file-name "The file is ")
1053 ;; @r{After evaluation of the preceding expression,}
1054 ;; @r{the following appears in the minibuffer:}
1058 ---------- Buffer: Minibuffer ----------
1059 The file is /gp/gnu/elisp/@point{}
1060 ---------- Buffer: Minibuffer ----------
1065 Typing @kbd{manual @key{TAB}} results in the following:
1069 ---------- Buffer: Minibuffer ----------
1070 The file is /gp/gnu/elisp/manual.texi@point{}
1071 ---------- Buffer: Minibuffer ----------
1075 @c Wordy to avoid overfull hbox in smallbook mode.
1077 If the user types @key{RET}, @code{read-file-name} returns the file name
1078 as the string @code{"/gp/gnu/elisp/manual.texi"}.
1081 @defopt insert-default-directory
1082 This variable is used by @code{read-file-name}. Its value controls
1083 whether @code{read-file-name} starts by placing the name of the default
1084 directory in the minibuffer, plus the initial file name if any. If the
1085 value of this variable is @code{nil}, then @code{read-file-name} does
1086 not place any initial input in the minibuffer (unless you specify
1087 initial input with the @var{initial} argument). In that case, the
1088 default directory is still used for completion of relative file names,
1089 but is not displayed.
1095 ;; @r{Here the minibuffer starts out with the default directory.}
1096 (let ((insert-default-directory t))
1097 (read-file-name "The file is "))
1101 ---------- Buffer: Minibuffer ----------
1102 The file is ~lewis/manual/@point{}
1103 ---------- Buffer: Minibuffer ----------
1107 ;; @r{Here the minibuffer is empty and only the prompt}
1108 ;; @r{appears on its line.}
1109 (let ((insert-default-directory nil))
1110 (read-file-name "The file is "))
1114 ---------- Buffer: Minibuffer ----------
1115 The file is @point{}
1116 ---------- Buffer: Minibuffer ----------
1121 @node Programmed Completion
1122 @subsection Programmed Completion
1123 @cindex programmed completion
1125 Sometimes it is not possible to create an alist or an obarray
1126 containing all the intended possible completions. In such a case, you
1127 can supply your own function to compute the completion of a given string.
1128 This is called @dfn{programmed completion}.
1130 To use this feature, pass a symbol with a function definition as the
1131 @var{collection} argument to @code{completing-read}. The function
1132 @code{completing-read} arranges to pass your completion function along
1133 to @code{try-completion} and @code{all-completions}, which will then let
1134 your function do all the work.
1136 The completion function should accept three arguments:
1140 The string to be completed.
1143 The predicate function to filter possible matches, or @code{nil} if
1144 none. Your function should call the predicate for each possible match,
1145 and ignore the possible match if the predicate returns @code{nil}.
1148 A flag specifying the type of operation.
1151 There are three flag values for three operations:
1155 @code{nil} specifies @code{try-completion}. The completion function
1156 should return the completion of the specified string, or @code{t} if the
1157 string is a unique and exact match already, or @code{nil} if the string
1158 matches no possibility.
1160 If the string is an exact match for one possibility, but also matches
1161 other longer possibilities, the function should return the string, not
1165 @code{t} specifies @code{all-completions}. The completion function
1166 should return a list of all possible completions of the specified
1170 @code{lambda} specifies a test for an exact match. The completion
1171 function should return @code{t} if the specified string is an exact
1172 match for some possibility; @code{nil} otherwise.
1175 It would be consistent and clean for completion functions to allow
1176 lambda expressions (lists that are functions) as well as function
1177 symbols as @var{collection}, but this is impossible. Lists as
1178 completion tables are already assigned another meaning---as alists. It
1179 would be unreliable to fail to handle an alist normally because it is
1180 also a possible function. So you must arrange for any function you wish
1181 to use for completion to be encapsulated in a symbol.
1183 Emacs uses programmed completion when completing file names.
1184 @xref{File Name Completion}.
1186 @node Yes-or-No Queries
1187 @section Yes-or-No Queries
1188 @cindex asking the user questions
1189 @cindex querying the user
1190 @cindex yes-or-no questions
1192 This section describes functions used to ask the user a yes-or-no
1193 question. The function @code{y-or-n-p} can be answered with a single
1194 character; it is useful for questions where an inadvertent wrong answer
1195 will not have serious consequences. @code{yes-or-no-p} is suitable for
1196 more momentous questions, since it requires three or four characters to
1199 If either of these functions is called in a command that was invoked
1200 using the mouse---more precisely, if @code{last-nonmenu-event}
1201 (@pxref{Command Loop Info}) is either @code{nil} or a list---then it
1202 uses a dialog box or pop-up menu to ask the question. Otherwise, it
1203 uses keyboard input. You can force use of the mouse or use of keyboard
1204 input by binding @code{last-nonmenu-event} to a suitable value around
1207 Strictly speaking, @code{yes-or-no-p} uses the minibuffer and
1208 @code{y-or-n-p} does not; but it seems best to describe them together.
1210 @defun y-or-n-p prompt
1211 This function asks the user a question, expecting input in the echo
1212 area. It returns @code{t} if the user types @kbd{y}, @code{nil} if the
1213 user types @kbd{n}. This function also accepts @key{SPC} to mean yes
1214 and @key{DEL} to mean no. It accepts @kbd{C-]} to mean ``quit'', like
1215 @kbd{C-g}, because the question might look like a minibuffer and for
1216 that reason the user might try to use @kbd{C-]} to get out. The answer
1217 is a single character, with no @key{RET} needed to terminate it. Upper
1218 and lower case are equivalent.
1220 ``Asking the question'' means printing @var{prompt} in the echo area,
1221 followed by the string @w{@samp{(y or n) }}. If the input is not one of
1222 the expected answers (@kbd{y}, @kbd{n}, @kbd{@key{SPC}},
1223 @kbd{@key{DEL}}, or something that quits), the function responds
1224 @samp{Please answer y or n.}, and repeats the request.
1226 This function does not actually use the minibuffer, since it does not
1227 allow editing of the answer. It actually uses the echo area (@pxref{The
1228 Echo Area}), which uses the same screen space as the minibuffer. The
1229 cursor moves to the echo area while the question is being asked.
1231 The answers and their meanings, even @samp{y} and @samp{n}, are not
1232 hardwired. The keymap @code{query-replace-map} specifies them.
1233 @xref{Search and Replace}.
1235 In the following example, the user first types @kbd{q}, which is
1236 invalid. At the next prompt the user types @kbd{y}.
1240 (y-or-n-p "Do you need a lift? ")
1242 ;; @r{After evaluation of the preceding expression,}
1243 ;; @r{the following prompt appears in the echo area:}
1247 ---------- Echo area ----------
1248 Do you need a lift? (y or n)
1249 ---------- Echo area ----------
1252 ;; @r{If the user then types @kbd{q}, the following appears:}
1255 ---------- Echo area ----------
1256 Please answer y or n. Do you need a lift? (y or n)
1257 ---------- Echo area ----------
1260 ;; @r{When the user types a valid answer,}
1261 ;; @r{it is displayed after the question:}
1264 ---------- Echo area ----------
1265 Do you need a lift? (y or n) y
1266 ---------- Echo area ----------
1271 We show successive lines of echo area messages, but only one actually
1272 appears on the screen at a time.
1275 @defun y-or-n-p-with-timeout prompt seconds default-value
1276 Like @code{y-or-n-p}, except that if the user fails to answer within
1277 @var{seconds} seconds, this function stops waiting and returns
1278 @var{default-value}. It works by setting up a timer; see @ref{Timers}.
1279 The argument @var{seconds} may be an integer or a floating point number.
1282 @defun yes-or-no-p prompt
1283 This function asks the user a question, expecting input in the
1284 minibuffer. It returns @code{t} if the user enters @samp{yes},
1285 @code{nil} if the user types @samp{no}. The user must type @key{RET} to
1286 finalize the response. Upper and lower case are equivalent.
1288 @code{yes-or-no-p} starts by displaying @var{prompt} in the echo area,
1289 followed by @w{@samp{(yes or no) }}. The user must type one of the
1290 expected responses; otherwise, the function responds @samp{Please answer
1291 yes or no.}, waits about two seconds and repeats the request.
1293 @code{yes-or-no-p} requires more work from the user than
1294 @code{y-or-n-p} and is appropriate for more crucial decisions.
1300 (yes-or-no-p "Do you really want to remove everything? ")
1302 ;; @r{After evaluation of the preceding expression,}
1303 ;; @r{the following prompt appears,}
1304 ;; @r{with an empty minibuffer:}
1308 ---------- Buffer: minibuffer ----------
1309 Do you really want to remove everything? (yes or no)
1310 ---------- Buffer: minibuffer ----------
1315 If the user first types @kbd{y @key{RET}}, which is invalid because this
1316 function demands the entire word @samp{yes}, it responds by displaying
1317 these prompts, with a brief pause between them:
1321 ---------- Buffer: minibuffer ----------
1322 Please answer yes or no.
1323 Do you really want to remove everything? (yes or no)
1324 ---------- Buffer: minibuffer ----------
1329 @node Multiple Queries
1330 @section Asking Multiple Y-or-N Questions
1332 When you have a series of similar questions to ask, such as ``Do you
1333 want to save this buffer'' for each buffer in turn, you should use
1334 @code{map-y-or-n-p} to ask the collection of questions, rather than
1335 asking each question individually. This gives the user certain
1336 convenient facilities such as the ability to answer the whole series at
1339 @defun map-y-or-n-p prompter actor list &optional help action-alist
1340 This function asks the user a series of questions, reading a
1341 single-character answer in the echo area for each one.
1343 The value of @var{list} specifies the objects to ask questions about.
1344 It should be either a list of objects or a generator function. If it is
1345 a function, it should expect no arguments, and should return either the
1346 next object to ask about, or @code{nil} meaning stop asking questions.
1348 The argument @var{prompter} specifies how to ask each question. If
1349 @var{prompter} is a string, the question text is computed like this:
1352 (format @var{prompter} @var{object})
1356 where @var{object} is the next object to ask about (as obtained from
1359 If not a string, @var{prompter} should be a function of one argument
1360 (the next object to ask about) and should return the question text. If
1361 the value is a string, that is the question to ask the user. The
1362 function can also return @code{t} meaning do act on this object (and
1363 don't ask the user), or @code{nil} meaning ignore this object (and don't
1366 The argument @var{actor} says how to act on the answers that the user
1367 gives. It should be a function of one argument, and it is called with
1368 each object that the user says yes for. Its argument is always an
1369 object obtained from @var{list}.
1371 If the argument @var{help} is given, it should be a list of this form:
1374 (@var{singular} @var{plural} @var{action})
1378 where @var{singular} is a string containing a singular noun that
1379 describes the objects conceptually being acted on, @var{plural} is the
1380 corresponding plural noun, and @var{action} is a transitive verb
1381 describing what @var{actor} does.
1383 If you don't specify @var{help}, the default is @code{("object"
1384 "objects" "act on")}.
1386 Each time a question is asked, the user may enter @kbd{y}, @kbd{Y}, or
1387 @key{SPC} to act on that object; @kbd{n}, @kbd{N}, or @key{DEL} to skip
1388 that object; @kbd{!} to act on all following objects; @key{ESC} or
1389 @kbd{q} to exit (skip all following objects); @kbd{.} (period) to act on
1390 the current object and then exit; or @kbd{C-h} to get help. These are
1391 the same answers that @code{query-replace} accepts. The keymap
1392 @code{query-replace-map} defines their meaning for @code{map-y-or-n-p}
1393 as well as for @code{query-replace}; see @ref{Search and Replace}.
1395 You can use @var{action-alist} to specify additional possible answers
1396 and what they mean. It is an alist of elements of the form
1397 @code{(@var{char} @var{function} @var{help})}, each of which defines one
1398 additional answer. In this element, @var{char} is a character (the
1399 answer); @var{function} is a function of one argument (an object from
1400 @var{list}); @var{help} is a string.
1402 When the user responds with @var{char}, @code{map-y-or-n-p} calls
1403 @var{function}. If it returns non-@code{nil}, the object is considered
1404 ``acted upon'', and @code{map-y-or-n-p} advances to the next object in
1405 @var{list}. If it returns @code{nil}, the prompt is repeated for the
1408 If @code{map-y-or-n-p} is called in a command that was invoked using the
1409 mouse---more precisely, if @code{last-nonmenu-event} (@pxref{Command
1410 Loop Info}) is either @code{nil} or a list---then it uses a dialog box
1411 or pop-up menu to ask the question. In this case, it does not use
1412 keyboard input or the echo area. You can force use of the mouse or use
1413 of keyboard input by binding @code{last-nonmenu-event} to a suitable
1414 value around the call.
1416 The return value of @code{map-y-or-n-p} is the number of objects acted on.
1419 @node Reading a Password
1420 @section Reading a Password
1422 This function is useful for reading passwords.
1424 @defun read-password prompt default
1425 @tindex read-password
1426 This function reads a password, echoing @samp{.} in the echo area
1427 for each character entered, and returns it as a string. It prompts
1428 with @var{prompt}, and returns @var{default} if the user enters the
1432 @node Minibuffer Misc
1433 @section Minibuffer Miscellany
1435 This section describes some basic functions and variables related to
1438 @deffn Command exit-minibuffer
1439 This command exits the active minibuffer. It is normally bound to
1440 keys in minibuffer local keymaps.
1443 @deffn Command self-insert-and-exit
1444 This command exits the active minibuffer after inserting the last
1445 character typed on the keyboard (found in @code{last-command-char};
1446 @pxref{Command Loop Info}).
1449 @deffn Command previous-history-element n
1450 This command replaces the minibuffer contents with the value of the
1451 @var{n}th previous (older) history element.
1454 @deffn Command next-history-element n
1455 This command replaces the minibuffer contents with the value of the
1456 @var{n}th more recent history element.
1459 @deffn Command previous-matching-history-element pattern
1460 This command replaces the minibuffer contents with the value of the
1461 previous (older) history element that matches @var{pattern} (a regular
1465 @deffn Command next-matching-history-element pattern
1466 This command replaces the minibuffer contents with the value of the next
1467 (newer) history element that matches @var{pattern} (a regular
1471 @defun minibuffer-prompt
1472 This function returns the prompt string of the currently active
1473 minibuffer. If no minibuffer is active, it returns @code{nil}.
1476 @defun minibuffer-prompt-width
1477 This function returns the display width of the prompt string of the
1478 currently active minibuffer. If no minibuffer is active, it returns 0.
1481 @defvar minibuffer-setup-hook
1482 This is a normal hook that is run whenever the minibuffer is entered.
1486 @defvar minibuffer-exit-hook
1487 This is a normal hook that is run whenever the minibuffer is exited.
1491 @defvar minibuffer-help-form
1492 The current value of this variable is used to rebind @code{help-form}
1493 locally inside the minibuffer (@pxref{Help Functions}).
1496 @defun active-minibuffer-window
1497 This function returns the currently active minibuffer window, or
1498 @code{nil} if none is currently active.
1501 @defun minibuffer-window &optional frame
1502 This function returns the minibuffer window used for frame @var{frame}.
1503 If @var{frame} is @code{nil}, that stands for the current frame. Note
1504 that the minibuffer window used by a frame need not be part of that
1505 frame---a frame that has no minibuffer of its own necessarily uses some
1506 other frame's minibuffer window.
1510 @defun window-minibuffer-p window
1511 This function returns non-@code{nil} if @var{window} is a minibuffer window.
1514 It is not correct to determine whether a given window is a minibuffer by
1515 comparing it with the result of @code{(minibuffer-window)}, because
1516 there can be more than one minibuffer window if there is more than one
1519 @defun minibuffer-window-active-p window
1520 This function returns non-@code{nil} if @var{window}, assumed to be
1521 a minibuffer window, is currently active.
1524 @defvar minibuffer-scroll-window
1525 If the value of this variable is non-@code{nil}, it should be a window
1526 object. When the function @code{scroll-other-window} is called in the
1527 minibuffer, it scrolls this window.
1530 Finally, some functions and variables deal with recursive minibuffers
1531 (@pxref{Recursive Editing}):
1533 @defun minibuffer-depth
1534 This function returns the current depth of activations of the
1535 minibuffer, a nonnegative integer. If no minibuffers are active, it
1539 @defopt enable-recursive-minibuffers
1540 If this variable is non-@code{nil}, you can invoke commands (such as
1541 @code{find-file}) that use minibuffers even while the minibuffer window
1542 is active. Such invocation produces a recursive editing level for a new
1543 minibuffer. The outer-level minibuffer is invisible while you are
1544 editing the inner one.
1546 If this variable is @code{nil}, you cannot invoke minibuffer
1547 commands when the minibuffer window is active, not even if you switch to
1548 another window to do it.
1552 If a command name has a property @code{enable-recursive-minibuffers}
1553 that is non-@code{nil}, then the command can use the minibuffer to read
1554 arguments even if it is invoked from the minibuffer. The minibuffer
1555 command @code{next-matching-history-element} (normally @kbd{M-s} in the
1556 minibuffer) uses this feature.