@c -*-texinfo-*-
@c This is part of the GNU Emacs Lisp Reference Manual.
-@c Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995, 1998, 1999, 2001
+@c Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995, 1998, 1999,
+@c 2001, 2004
@c Free Software Foundation, Inc.
@c See the file elisp.texi for copying conditions.
@setfilename ../info/minibuf
* Object from Minibuffer:: How to read a Lisp object or expression.
* Minibuffer History:: Recording previous minibuffer inputs
so the user can reuse them.
+* Initial Input:: Specifying initial contents for the minibuffer.
* Completion:: How to invoke and customize completion.
* Yes-or-No Queries:: Asking a question with a simple answer.
* Multiple Queries:: Asking a series of similar questions.
just a minibuffer, you can change the minibuffer's size by changing the
frame's size.
+ Use of the minibuffer reads input events, and that alters the values
+of variables such as @code{this-command} and @code{last-command}
+(@pxref{Command Loop Info}). Your program should bind them around the
+code that uses the minibuffer, if you do not want that to change them.
+
If a command uses a minibuffer while there is an active minibuffer,
this is called a @dfn{recursive minibuffer}. The first minibuffer is
named @w{@samp{ *Minibuf-0*}}. Recursive minibuffers are named by
Most often, the minibuffer is used to read text as a string. It can
also be used to read a Lisp object in textual form. The most basic
primitive for minibuffer input is @code{read-from-minibuffer}; it can do
-either one.
+either one. There are also specialized commands for reading
+commands, variables, file names, etc. (@pxref{Completion}).
In most cases, you should not call minibuffer input functions in the
middle of a Lisp function. Instead, do all minibuffer input as part of
reading the arguments for a command, in the @code{interactive}
specification. @xref{Defining Commands}.
-@defun read-from-minibuffer prompt-string &optional initial-contents keymap read hist default inherit-input-method
+@defun read-from-minibuffer prompt-string &optional initial-contents keymap read hist default inherit-input-method keep-all
This function is the most general way to get input through the
minibuffer. By default, it accepts arbitrary text and returns it as a
string; however, if @var{read} is non-@code{nil}, then it uses
(@xref{Input Functions}, for information about reading.)
The argument @var{default} specifies a default value to make available
-through the history commands. It should be a string, or @code{nil}. If
-@var{read} is non-@code{nil}, then @var{default} is also used as the
-input to @code{read}, if the user enters empty input. However, in the
-usual case (where @var{read} is @code{nil}), @code{read-from-minibuffer}
-does not return @var{default} when the user enters empty input; it
-returns an empty string, @code{""}. In this respect, it is different
-from all the other minibuffer input functions in this chapter.
+through the history commands. It should be a string, or @code{nil}.
+If non-@code{nil}, the user can access it using
+@code{next-history-element}, usually bound in the minibuffer to
+@kbd{M-n}. If @var{read} is non-@code{nil}, then @var{default} is
+also used as the input to @code{read}, if the user enters empty input.
+(If @var{read} is non-@code{nil} and @var{default} is @code{nil}, empty
+input results in an @code{end-of-file} error.) However, in the usual
+case (where @var{read} is @code{nil}), @code{read-from-minibuffer}
+ignores @var{default} when the user enters empty input and returns an
+empty string, @code{""}. In this respect, it is different from all
+the other minibuffer input functions in this chapter.
If @var{keymap} is non-@code{nil}, that keymap is the local keymap to
use in the minibuffer. If @var{keymap} is omitted or @code{nil}, the
Representations}) from whichever buffer was current before entering the
minibuffer.
-If @var{initial-contents} is a string, @code{read-from-minibuffer}
-inserts it into the minibuffer, leaving point at the end, before the
-user starts to edit the text. The minibuffer appears with this text as
-its initial contents.
-
-Alternatively, @var{initial-contents} can be a cons cell of the form
-@code{(@var{string} . @var{position})}. This means to insert
-@var{string} in the minibuffer but put point @var{position} characters
-from the beginning, rather than at the end.
-
-@strong{Usage note:} The @var{initial-contents} argument and the
-@var{default} argument are two alternative features for more or less the
-same job. It does not make sense to use both features in a single call
-to @code{read-from-minibuffer}. In general, we recommend using
-@var{default}, since this permits the user to insert the default value
-when it is wanted, but does not burden the user with deleting it from
-the minibuffer on other occasions.
+If @var{keep-all} is non-@code{nil}, even empty and duplicate inputs
+are added to the history list.
+
+Use of @var{initial-contents} is mostly deprecated; we recommend using
+a non-@code{nil} value only in conjunction with specifying a cons cell
+for @var{hist}. @xref{Initial Input}.
@end defun
@defun read-string prompt &optional initial history default inherit-input-method
This function reads a string from the minibuffer and returns it. The
-arguments @var{prompt} and @var{initial} are used as in
-@code{read-from-minibuffer}. The keymap used is
-@code{minibuffer-local-map}.
+arguments @var{prompt}, @var{initial}, @var{history} and
+@var{inherit-input-method} are used as in @code{read-from-minibuffer}.
+The keymap used is @code{minibuffer-local-map}.
-The optional argument @var{history}, if non-@code{nil}, specifies a
-history list and optionally the initial position in the list. The
-optional argument @var{default} specifies a default value to return if
-the user enters null input; it should be a string. The optional
-argument @var{inherit-input-method} specifies whether to inherit the
-current buffer's input method.
+The optional argument @var{default} is used as in
+@code{read-from-minibuffer}, except that, if non-@code{nil}, it also
+specifies a default value to return if the user enters null input. As
+in @code{read-from-minibuffer} it should be a string, or @code{nil},
+which is equivalent to an empty string.
This function is a simplified interface to the
@code{read-from-minibuffer} function:
(let ((value
(read-from-minibuffer @var{prompt} @var{initial} nil nil
@var{history} @var{default} @var{inherit})))
- (if (equal value "")
+ (if (and (equal value "") @var{default})
@var{default}
value))
@end group
@defvar minibuffer-allow-text-properties
If this variable is @code{nil}, then @code{read-from-minibuffer} strips
all text properties from the minibuffer input before returning it.
-Since all minibuffer input uses @code{read-from-minibuffer}, this
-variable applies to all minibuffer input.
-
-Note that the completion functions discard text properties unconditionally,
-regardless of the value of this variable.
+This variable also affects @code{read-string}. However,
+@code{read-no-blanks-input} (see below), as well as
+@code{read-minibuffer} and related functions (@pxref{Object from
+Minibuffer,, Reading Lisp Objects With the Minibuffer}), and all
+functions that do minibuffer input with completion, discard text
+properties unconditionally, regardless of the value of this variable.
@end defvar
@defvar minibuffer-local-map
+@anchor{Definition of minibuffer-local-map}
This is the default local keymap for reading from the minibuffer. By
default, it makes the following bindings:
@code{abort-recursive-edit}
@item @kbd{M-n}
+@itemx @key{DOWN}
@code{next-history-element}
@item @kbd{M-p}
+@itemx @key{UP}
@code{previous-history-element}
-@item @kbd{M-r}
+@item @kbd{M-s}
@code{next-matching-history-element}
-@item @kbd{M-s}
+@item @kbd{M-r}
@code{previous-matching-history-element}
@end table
@end defvar
@code{minibuffer-local-ns-map} does not rebind @kbd{C-q}, it @emph{is}
possible to put a space into the string, by quoting it.
+This function discards text properties, regardless of the value of
+@code{minibuffer-allow-text-properties}.
+
@smallexample
@group
(read-no-blanks-input @var{prompt} @var{initial})
@equiv{}
-(read-from-minibuffer @var{prompt} @var{initial} minibuffer-local-ns-map)
+(let (minibuffer-allow-text-properties)
+ (read-from-minibuffer @var{prompt} @var{initial} minibuffer-local-ns-map))
@end group
@end smallexample
@end defun
@group
(read-minibuffer @var{prompt} @var{initial})
@equiv{}
-(read-from-minibuffer @var{prompt} @var{initial} nil t)
+(let (minibuffer-allow-text-properties)
+ (read-from-minibuffer @var{prompt} @var{initial} nil t))
@end group
@end smallexample
@item (@var{variable} . @var{startpos})
Use @var{variable} (a symbol) as the history list, and assume that the
-initial history position is @var{startpos} (an integer, counting from
-zero which specifies the most recent element of the history).
-
-If you specify @var{startpos}, then you should also specify that element
-of the history as the initial minibuffer contents, for consistency.
+initial history position is @var{startpos} (a nonnegative integer).
+
+Specifying 0 for @var{startpos} is equivalent to just specifying the
+symbol @var{variable}. @code{previous-history-element} will display
+the most recent element of the history list in the minibuffer. If you
+specify a positive @var{startpos}, the minibuffer history functions
+behave as if @code{(elt @var{variable} (1- @var{STARTPOS}))} were the
+history element currently shown in the minibuffer.
+
+For consistency, you should also specify that element of the history
+as the initial minibuffer contents, using the @var{initial} argument
+to the minibuffer input function (@pxref{Initial Input}).
@end table
If you don't specify @var{hist}, then the default history list
@code{history-length} specifies the maximum length for most history
lists. To specify a different maximum length for a particular history
list, put the length in the @code{history-length} property of the
-history list symbol.
+history list symbol. The variable @code{history-delete-duplicates}
+specifies whether to delete duplicates in history.
@defvar history-length
The value of this variable specifies the maximum length for all
history lists that don't specify their own maximum lengths. If the
value is @code{t}, that means there no maximum (don't delete old
elements).
+@end defvar
+
+@defvar history-delete-duplicates
+If the value of this variable is @code{t}, that means when adding a
+new history element, all previous identical elements are deleted.
@end defvar
Here are some of the standard minibuffer history list variables:
A history list for arguments that are Lisp expressions to evaluate.
@end defvar
+@node Initial Input
+@section Initial Input
+
+Several of the functions for minibuffer input have an argument called
+@var{initial} or @var{initial-contents}. This is a mostly-deprecated
+feature for specifiying that the minibuffer should start out with
+certain text, instead of empty as usual.
+
+If @var{initial} is a string, the minibuffer starts out containing the
+text of the string, with point at the end, when the user starts to
+edit the text. If the user simply types @key{RET} to exit the
+minibuffer, it will use the initial input string to determine the
+value to return.
+
+@strong{We discourage use of a non-@code{nil} value for
+@var{initial}}, because initial input is an intrusive interface.
+History lists and default values provide a much more convenient method
+to offer useful default inputs to the user.
+
+There is just one situation where you should specify a string for an
+@var{initial} argument. This is when you specify a cons cell for the
+@var{hist} or @var{history} argument. @xref{Minibuffer History}.
+
+@var{initial} can also be a cons cell of the form @code{(@var{string}
+. @var{position})}. This means to insert @var{string} in the
+minibuffer but put point at @var{position} within the string's text.
+
+As a historical accident, @var{position} was implemented
+inconsistently in different functions. In @code{completing-read},
+@var{position}'s value is interpreted as origin-zero; that is, a value
+of 0 means the beginning of the string, 1 means after the first
+character, etc. In @code{read-minibuffer}, and the other
+non-completion minibuffer input functions that support this argument,
+1 means the beginning of the string 2 means after the first character,
+etc.
+
+Use of a cons cell as the value for @var{initial} arguments is
+deprecated in user code.
+
@node Completion
@section Completion
@cindex completion
@defun try-completion string collection &optional predicate
This function returns the longest common substring of all possible
completions of @var{string} in @var{collection}. The value of
-@var{collection} must be a list of strings, an alist, an obarray, or a
-function that implements a virtual set of strings (see below).
+@var{collection} must be a list of strings or symbols, an alist, an
+obarray, a hash table, or a function that implements a virtual set of
+strings (see below).
Completion compares @var{string} against each of the permissible
completions specified by @var{collection}; if the beginning of the
match.
If @var{collection} is an alist (@pxref{Association Lists}), the
-@sc{car}s of the alist elements form the set of permissible completions.
+permissible completions are the elements of the alist that are either
+strings, symbols, or conses whose @sc{car} is a string or symbol.
+Symbols are converted to strings using @code{symbol-name}.
+Other elements of the alist are ignored. (Remember that in Emacs Lisp,
+the elements of alists do not @emph{have} to be conses.) As all
+elements of the alist can be strings, this case actually includes
+lists of strings or symbols, even though we usually do not think of
+such lists as alists.
@cindex obarray in completion
If @var{collection} is an obarray (@pxref{Creating Symbols}), the names
empty and then add symbols to it one by one using @code{intern}.
Also, you cannot intern a given symbol in more than one obarray.
+If @var{collection} is a hash table, then the keys that are strings
+are the possible completions. Other keys are ignored.
+
You can also use a symbol that is a function as @var{collection}. Then
the function is solely responsible for performing completion;
@code{try-completion} returns whatever this function returns. The
thing in either case.) @xref{Programmed Completion}.
If the argument @var{predicate} is non-@code{nil}, then it must be a
-function of one argument. It is used to test each possible match, and
-the match is accepted only if @var{predicate} returns non-@code{nil}.
-The argument given to @var{predicate} is either a string from the
-list, a cons cell from the alist (the @sc{car} of which is a string)
-or a symbol (@emph{not} a symbol name) from the obarray.
+function of one argument, unless @var{collection} is a hash table, in
+which case it should be a function of two arguments. It is used to
+test each possible match, and the match is accepted only if
+@var{predicate} returns non-@code{nil}. The argument given to
+@var{predicate} is either a string or a cons cell (the @sc{car} of
+which is a string) from the alist, or a symbol (@emph{not} a symbol
+name) from the obarray. If @var{collection} is a hash table,
+@var{predicate} is called with two arguments, the string key and the
+associated value.
+
+In addition, to be acceptable, a completion must also match all the
+regular expressions in @code{completion-regexp-list}. (Unless
+@var{collection} is a function, in which case that function has to
+handle @code{completion-regexp-list} itself.)
In the first of the following examples, the string @samp{foo} is
matched by three of the alist @sc{car}s. All of the matches begin with
@defun all-completions string collection &optional predicate nospace
This function returns a list of all possible completions of
-@var{string}. The arguments to this function (aside from @var{nospace})
-are the same as those of @code{try-completion}. If @var{nospace} is
-non-@code{nil}, completions that start with a space are ignored unless
-@var{string} also starts with a space.
+@var{string}. The arguments to this function (aside from
+@var{nospace}) are the same as those of @code{try-completion}. Also,
+this function uses @code{completion-regexp-list} in the same way that
+@code{try-completion} does. The optional argument @var{nospace} only
+matters if @var{string} is the empty string. In that case, if
+@var{nospace} is non-@code{nil}, completions that start with a space
+are ignored.
If @var{collection} is a function, it is called with three arguments:
@var{string}, @var{predicate} and @code{t}; then @code{all-completions}
@end defun
@defun test-completion string collection &optional predicate
+@anchor{Definition of test-completion}
This function returns non-@code{nil} if @var{string} is a valid
completion possibility specified by @var{collection} and
-@var{predicate}. The other arguments are the same as in
-@code{try-completion}. For instance, if @var{collection} is a list,
-this is true if @var{string} appears in the list and @var{predicate}
-is satisfied.
+@var{predicate}. The arguments are the same as in
+@code{try-completion}. For instance, if @var{collection} is a list of
+strings, this is true if @var{string} appears in the list and
+@var{predicate} is satisfied.
+
+@code{test-completion} uses @code{completion-regexp-list} in the same
+way that @code{try-completion} does.
+
+If @var{predicate} is non-@code{nil} and if @var{collection} contains
+several strings that are equal to each other, as determined by
+@code{compare-strings} according to @code{completion-ignore-case},
+then @var{predicate} should accept either all or none of them.
+Otherwise, the return value of @code{test-completion} is essentially
+unpredictable.
If @var{collection} is a function, it is called with three arguments,
the values @var{string}, @var{predicate} and @code{lambda}; whatever
consider case significant in completion.
@end defvar
+@defvar completion-regexp-list
+This is a list of regular expressions. The completion functions only
+consider a completion acceptable if it matches all regular expressions
+in this list, with @code{case-fold-search} (@pxref{Searching and Case})
+bound to the value of @code{completion-ignore-case}.
+@end defvar
+
@defmac lazy-completion-table var fun &rest args
This macro provides a way to initialize the variable @var{var} as a
collection for completion in a lazy way, not computing its actual
@var{prompt}, which must be a string.
The actual completion is done by passing @var{collection} and
-@var{predicate} to the function @code{try-completion}. This happens in
-certain commands bound in the local keymaps used for completion.
+@var{predicate} to the function @code{try-completion}. This happens
+in certain commands bound in the local keymaps used for completion.
+Some of these commands also call @code{test-completion}. Thus, if
+@var{predicate} is non-@code{nil}, it should be compatible with
+@var{collection} and @code{completion-ignore-case}. @xref{Definition
+of test-completion}.
If @var{require-match} is @code{nil}, the exit commands work regardless
of the input in the minibuffer. If @var{require-match} is @code{t}, the
However, empty input is always permitted, regardless of the value of
@var{require-match}; in that case, @code{completing-read} returns
-@var{default}. The value of @var{default} (if non-@code{nil}) is also
-available to the user through the history commands.
-
-The user can exit with null input by typing @key{RET} with an empty
-minibuffer. Then @code{completing-read} returns @code{""}. This is how
-the user requests whatever default the command uses for the value being
-read. The user can return using @key{RET} in this way regardless of the
-value of @var{require-match}, and regardless of whether the empty string
-is included in @var{collection}.
-
-The function @code{completing-read} works by calling
-@code{read-minibuffer}. It uses @code{minibuffer-local-completion-map}
-as the keymap if @var{require-match} is @code{nil}, and uses
+@var{default}, or @code{""}, if @var{default} is @code{nil}. The
+value of @var{default} (if non-@code{nil}) is also available to the
+user through the history commands.
+
+The function @code{completing-read} uses
+@code{minibuffer-local-completion-map} as the keymap if
+@var{require-match} is @code{nil}, and uses
@code{minibuffer-local-must-match-map} if @var{require-match} is
non-@code{nil}. @xref{Completion Commands}.
saving the input and for minibuffer history commands. It defaults to
@code{minibuffer-history}. @xref{Minibuffer History}.
-If @var{initial} is non-@code{nil}, @code{completing-read} inserts it
-into the minibuffer as part of the input. Then it allows the user to
-edit the input, providing several commands to attempt completion.
-In most cases, we recommend using @var{default}, and not @var{initial}.
-
-@strong{We discourage use of a non-@code{nil} value for
-@var{initial}}, because it is an intrusive interface. The history
-list feature (which did not exist when we introduced @var{initial})
-offers a far more convenient and general way for the user to get the
-default and edit it, and it is always available.
+The argument @var{initial} is mostly deprecated; we recommend using a
+non-@code{nil} value only in conjunction with specifying a cons cell
+for @var{hist}. @xref{Initial Input}. For default input, use
+@var{default} instead.
If the argument @var{inherit-input-method} is non-@code{nil}, then the
minibuffer inherits the current input method (@pxref{Input
(@pxref{Text Representations}) from whichever buffer was current before
entering the minibuffer.
-Completion ignores case when comparing the input against the possible
-matches, if the built-in variable @code{completion-ignore-case} is
-non-@code{nil}. @xref{Basic Completion}.
+If the built-in variable @code{completion-ignore-case} is
+non-@code{nil}, completion ignores case when comparing the input
+against the possible matches. @xref{Basic Completion}. In this mode
+of operation, @var{predicate} must also ignore case, or you will get
+surprising results.
Here's an example of using @code{completing-read}:
@node Completion Commands
@subsection Minibuffer Commands that Do Completion
- This section describes the keymaps, commands and user options used in
-the minibuffer to do completion.
+ This section describes the keymaps, commands and user options used
+in the minibuffer to do completion. The description refers to the
+situation when Partial Completion mode is disabled (as it is by
+default). When enabled, this minor mode uses its own alternatives to
+some of the commands described below. @xref{Completion Options,,,
+emacs, The GNU Emacs Manual}, for a short description of Partial
+Completion mode.
@defvar minibuffer-local-completion-map
@code{completing-read} uses this value as the local keymap when an
@noindent
with other characters bound as in @code{minibuffer-local-map}
-(@pxref{Text from Minibuffer}).
+(@pxref{Definition of minibuffer-local-map}).
@end defvar
@defvar minibuffer-local-must-match-map
@end defvar
@defvar minibuffer-completion-table
-The value of this variable is the alist or obarray used for completion
-in the minibuffer. This is the global variable that contains what
+The value of this variable is the collection used for completion in
+the minibuffer. This is the global variable that contains what
@code{completing-read} passes to @code{try-completion}. It is used by
minibuffer completion commands such as @code{minibuffer-complete-word}.
@end defvar
information about streams.) The argument @var{completions} is normally
a list of completions just returned by @code{all-completions}, but it
does not have to be. Each element may be a symbol or a string, either
-of which is simply printed, or a list of two strings, which is printed
-as if the strings were concatenated.
+of which is simply printed. It can also be a list of two strings,
+which is printed as if the strings were concatenated. The first of
+the two strings is the actual completion, the second string serves as
+annotation.
This function is called by @code{minibuffer-completion-help}. The
most common way to use it is together with
If @var{existing} is non-@code{nil}, then the name specified must be
that of an existing buffer. The usual commands to exit the minibuffer
do not exit if the text is not valid, and @key{RET} does completion to
-attempt to find a valid name. (However, @var{default} is not checked
-for validity; it is returned, whatever it is, if the user exits with the
-minibuffer empty.)
+attempt to find a valid name. If @var{existing} is neither @code{nil}
+nor @code{t}, confirmation is required after completion. (However,
+@var{default} is not checked for validity; it is returned, whatever it
+is, if the user exits with the minibuffer empty.)
In the following example, the user enters @samp{minibuffer.t}, and
then types @key{RET}. The argument @var{existing} is @code{t}, and the
null input. It can be a symbol or a string; if it is a string,
@code{read-command} interns it before returning it. If @var{default} is
@code{nil}, that means no default has been specified; then if the user
-enters null input, the return value is @code{nil}.
+enters null input, the return value is @code{(intern "")}, that is, a
+symbol whose name is an empty string.
@example
(read-command "Command name? ")
@end defun
@defun read-variable prompt &optional default
+@anchor{Definition of read-variable}
This function reads the name of a user variable and returns it as a
symbol.
null input. It can be a symbol or a string; if it is a string,
@code{read-variable} interns it before returning it. If @var{default}
is @code{nil}, that means no default has been specified; then if the
-user enters null input, the return value is @code{nil}.
+user enters null input, the return value is @code{(intern "")}.
@example
@group
@defun read-file-name prompt &optional directory default existing initial predicate
This function reads a file name in the minibuffer, prompting with
-@var{prompt} and providing completion. If @var{default} is
-non-@code{nil}, then the function returns @var{default} if the user just
-types @key{RET}. @var{default} is not checked for validity; it is
-returned, whatever it is, if the user exits with the minibuffer empty.
+@var{prompt} and providing completion.
If @var{existing} is non-@code{nil}, then the user must specify the name
of an existing file; @key{RET} performs completion to make the name
acceptable.
The argument @var{directory} specifies the directory to use for
-completion of relative file names. If @code{insert-default-directory}
-is non-@code{nil}, @var{directory} is also inserted in the minibuffer as
-initial input. It defaults to the current buffer's value of
-@code{default-directory}.
+completion of relative file names. It should be an absolute directory
+name. If @code{insert-default-directory} is non-@code{nil},
+@var{directory} is also inserted in the minibuffer as initial input.
+It defaults to the current buffer's value of @code{default-directory}.
@c Emacs 19 feature
-If you specify @var{initial}, that is an initial file name to insert in
-the buffer (after @var{directory}, if that is inserted). In this
+If you specify @var{initial}, that is an initial file name to insert
+in the buffer (after @var{directory}, if that is inserted). In this
case, point goes at the beginning of @var{initial}. The default for
@var{initial} is @code{nil}---don't insert any file name. To see what
-@var{initial} does, try the command @kbd{C-x C-v}. @strong{Note:} we
-recommend using @var{default} rather than @var{initial} in most cases.
+@var{initial} does, try the command @kbd{C-x C-v}. @strong{Please
+note:} we recommend using @var{default} rather than @var{initial} in
+most cases.
+
+If @var{default} is non-@code{nil}, then the function returns
+@var{default} if the user exits the minibuffer with the same non-empty
+contents that @code{read-file-name} inserted initially. The initial
+minibuffer contents are always non-empty if
+@code{insert-default-directory} is non-@code{nil}, as it is by
+default. @var{default} is not checked for validity, regardless of the
+value of @var{existing}. However, if @var{existing} is
+non-@code{nil}, the initial minibuffer contents should be a valid file
+(or directory) name. Otherwise @code{read-file-name} attempts
+completion if the user exits without any editing, and does not return
+@var{default}. @var{default} is also available through the history
+commands.
+
+If @var{default} is @code{nil}, @code{read-file-name} tries to find a
+substitute default to use in its place, which it treats in exactly the
+same way as if it had been specified explicitly. If @var{default} is
+@code{nil}, but @var{initial} is non-@code{nil}, then the default is
+the absolute file name obtained from @var{directory} and
+@var{initial}. If both @var{default} and @var{initial} are @code{nil}
+and the buffer is visiting a file, @code{read-file-name} uses the
+absolute file name of that file as default. If the buffer is not
+visiting a file, then there is no default. In that case, if the user
+types @key{RET} without any editing, @code{read-file-name} simply
+returns the pre-inserted contents of the minibuffer.
+
+If the user types @key{RET} in an empty minibuffer, this function
+returns an empty string, regardless of the value of @var{existing}.
+This is, for instance, how the user can make the current buffer visit
+no file using @code{M-x set-visited-file-name}.
If @var{predicate} is non-@code{nil}, it specifies a function of one
argument that decides which file names are acceptable completion
possibilities. A file name is an acceptable value if @var{predicate}
returns non-@code{nil} for it.
+@code{read-file-name} does not automatically expand file names. You
+must call @code{expand-file-name} yourself if an absolute file name is
+required.
+
Here is an example:
@example
as the string @code{"/gp/gnu/elisp/manual.texi"}.
@end defun
+@defvar read-file-name-function
+If non-@code{nil}, this should be a function that accepts the same
+arguments as @code{read-file-name}. When @code{read-file-name} is
+called, it calls this function with the supplied arguments instead of
+doing its usual work.
+@end defvar
+
+@defvar read-file-name-completion-ignore-case
+If this variable is non-@code{nil}, @code{read-file-name} ignores case
+when performing completion.
+@end defvar
+
@defun read-directory-name prompt &optional directory default existing initial
This function is like @code{read-file-name} but allows only directory
names as completion possibilities.
+
+If @var{default} is @code{nil} and @var{initial} is non-@code{nil},
+@code{read-directory-name} constructs a substitute default by
+combining @var{directory} (or the current buffer's default directory
+if @var{directory} is @code{nil}) and @var{initial}. If both
+@var{default} and @var{initial} are @code{nil}, this function uses the
+current buffer's default directory as substitute default, ignoring
+@var{directory}.
@end defun
@defopt insert-default-directory
-This variable is used by @code{read-file-name}. Its value controls
-whether @code{read-file-name} starts by placing the name of the default
-directory in the minibuffer, plus the initial file name if any. If the
-value of this variable is @code{nil}, then @code{read-file-name} does
-not place any initial input in the minibuffer (unless you specify
-initial input with the @var{initial} argument). In that case, the
-default directory is still used for completion of relative file names,
-but is not displayed.
+This variable is used by @code{read-file-name}, and thus, indirectly,
+by most commands reading file names. (This includes all commands that
+use the code letters @samp{f} or @samp{F} in their interactive form.
+@xref{Interactive Codes,, Code Characters for interactive}.) Its
+value controls whether @code{read-file-name} starts by placing the
+name of the default directory in the minibuffer, plus the initial file
+name if any. If the value of this variable is @code{nil}, then
+@code{read-file-name} does not place any initial input in the
+minibuffer (unless you specify initial input with the @var{initial}
+argument). In that case, the default directory is still used for
+completion of relative file names, but is not displayed.
+
+If this variable is @code{nil} and the initial minibuffer contents are
+empty, the user may have to explicitly fetch the next history element
+to access a default value. If the variable is non-@code{nil}, the
+initial minibuffer contents are always non-empty and the user can
+always request a default value by immediately typing @key{RET} in an
+unedited minibuffer. (See above.)
For example:
@defun minibuffer-prompt-end
@tindex minibuffer-prompt-end
-This function, available starting in Emacs 21, returns the current
+This function returns the current
position of the end of the minibuffer prompt, if a minibuffer is
current. Otherwise, it returns the minimum valid buffer position.
@end defun
@defun minibuffer-contents
@tindex minibuffer-contents
-This function, available starting in Emacs 21, returns the editable
+This function returns the editable
contents of the minibuffer (that is, everything except the prompt) as
a string, if a minibuffer is current. Otherwise, it returns the
entire contents of the current buffer.
@defun delete-minibuffer-contents
@tindex delete-minibuffer-contents
-This function, available starting in Emacs 21, erases the editable
+This function erases the editable
contents of the minibuffer (that is, everything except the prompt), if
a minibuffer is current. Otherwise, it erases the entire buffer.
@end defun
@end defvar
@defvar minibuffer-help-form
+@anchor{Definition of minibuffer-help-form}
The current value of this variable is used to rebind @code{help-form}
locally inside the minibuffer (@pxref{Help Functions}).
@end defvar
-@defun minibufferp &optional buffer
-This function returns non-@code{nil} if @var{buffer} is a minibuffer.
-If @var{buffer} is omitted, it tests the current buffer.
+@defun minibufferp &optional buffer-or-name
+This function returns non-@code{nil} if @var{buffer-or-name} is a
+minibuffer. If @var{buffer-or-name} is omitted, it tests the current
+buffer.
@end defun
@defun active-minibuffer-window
@end defun
@defun minibuffer-window &optional frame
+@anchor{Definition of minibuffer-window}
This function returns the minibuffer window used for frame @var{frame}.
If @var{frame} is @code{nil}, that stands for the current frame. Note
that the minibuffer window used by a frame need not be part of that
other frame's minibuffer window.
@end defun
+@defun set-minibuffer-window window
+This function specifies @var{window} as the minibuffer window to use.
+This affects where the minibuffer is displayed if you put text in it
+without invoking the usual minibuffer commands. It has no effect on
+the usual minibuffer input functions because they all start by
+choosing the minibuffer window according to the current frame.
+@end defun
+
@c Emacs 19 feature
-@defun window-minibuffer-p window
-This function returns non-@code{nil} if @var{window} is a minibuffer window.
+@defun window-minibuffer-p &optional window
+This function returns non-@code{nil} if @var{window} is a minibuffer
+window.
+@var{window} defaults to the selected window.
@end defun
It is not correct to determine whether a given window is a minibuffer by
@end defun
@defvar minibuffer-scroll-window
+@anchor{Definition of minibuffer-scroll-window}
If the value of this variable is non-@code{nil}, it should be a window
object. When the function @code{scroll-other-window} is called in the
minibuffer, it scrolls this window.
@end defvar
+@defun minibuffer-selected-window
+This function returns the window which was selected when the
+minibuffer was entered. If selected window is not a minibuffer
+window, it returns @code{nil}.
+@end defun
+
Finally, some functions and variables deal with recursive minibuffers
(@pxref{Recursive Editing}):
@c Emacs 19 feature
If a command name has a property @code{enable-recursive-minibuffers}
that is non-@code{nil}, then the command can use the minibuffer to read
-arguments even if it is invoked from the minibuffer. The minibuffer
-command @code{next-matching-history-element} (normally @kbd{M-s} in the
-minibuffer) uses this feature.
+arguments even if it is invoked from the minibuffer. A command can
+also achieve this by binding @code{enable-recursive-minibuffers}
+to @code{t} in the interactive declaration (@pxref{Using Interactive}).
+The minibuffer command @code{next-matching-history-element} (normally
+@kbd{M-s} in the minibuffer) does the latter.
-@defun minibuffer-message string &optional timeout
+@defun minibuffer-message string
This function displays @var{string} temporarily at the end of the
-minibuffer text, for @var{timeout} seconds. (The default is 2
-seconds.)
+minibuffer text, for two seconds, or until the next input event
+arrives, whichever comes first.
@end defun
+
+@ignore
+ arch-tag: bba7f945-9078-477f-a2ce-18818a6e1218
+@end ignore
HCoop / bpt / emacs.git / blobdiff