@c Copyright (C) 1990-1995, 1998-1999, 2001-2012
@c Free Software Foundation, Inc.
@c See the file elisp.texi for copying conditions.
-@setfilename ../../info/buffers
-@node Buffers, Windows, Backups and Auto-Saving, Top
+@node Buffers
@chapter Buffers
@cindex buffer
* Buffer File Name:: The buffer file name indicates which file is visited.
* Buffer Modification:: A buffer is @dfn{modified} if it needs to be saved.
* Modification Time:: Determining whether the visited file was changed
- ``behind Emacs's back''.
+ "behind Emacs's back".
* Read Only Buffers:: Modifying text is not allowed in a read-only buffer.
* The Buffer List:: How to look at all the existing buffers.
* Creating Buffers:: Functions that create buffers.
@end menu
@node Buffer Basics
-@comment node-name, next, previous, up
@section Buffer Basics
@ifnottex
use.
If @var{filename} is @code{nil} or the empty string, that stands for
-``no visited file.'' In this case, @code{set-visited-file-name} marks
+``no visited file''. In this case, @code{set-visited-file-name} marks
the buffer as having no visited file, without changing the buffer's
modified flag.
@end defun
@node Modification Time
-@comment node-name, next, previous, up
@section Buffer Modification Time
@cindex comparing file modification time
@cindex modification time of buffer
@c Emacs 19 feature
@defun visited-file-modtime
This function returns the current buffer's recorded last file
-modification time, as a list of the form @code{(@var{high} @var{low})}.
+modification time, as a list of the form @code{(@var{high} @var{low}
+@var{microsec} @var{picosec})}.
(This is the same format that @code{file-attributes} uses to return
time values; see @ref{File Attributes}.)
visited file.
If @var{time} is neither @code{nil} nor zero, it should have the form
-@code{(@var{high} . @var{low})} or @code{(@var{high} @var{low})}, in
-either case containing two integers, each of which holds 16 bits of the
-time.
+@code{(@var{high} @var{low} @var{microsec} @var{picosec})},
+the format used by @code{current-time} (@pxref{Time of Day}).
This function is useful if the buffer was not read from the file
normally, or if the file itself has been changed for some known benign
@defvar inhibit-read-only
If this variable is non-@code{nil}, then read-only buffers and,
depending on the actual value, some or all read-only characters may be
-modified. Read-only characters in a buffer are those that have
-non-@code{nil} @code{read-only} properties (either text properties or
-overlay properties). @xref{Special Properties}, for more information
-about text properties. @xref{Overlays}, for more information about
-overlays and their properties.
+modified. Read-only characters in a buffer are those that have a
+non-@code{nil} @code{read-only} text property. @xref{Special
+Properties}, for more information about text properties.
If @code{inhibit-read-only} is @code{t}, all @code{read-only} character
properties have no effect. If @code{inhibit-read-only} is a list, then
of the list (comparison is done with @code{eq}).
@end defvar
-@deffn Command toggle-read-only &optional arg
-This command toggles whether the current buffer is read-only. It is
-intended for interactive use; do not use it in programs (it may have
-side-effects, such as enabling View mode, and does not affect
-read-only text properties). To change the read-only state of a buffer in
-a program, explicitly set @code{buffer-read-only} to the proper value.
-To temporarily ignore a read-only state, bind @code{inhibit-read-only}.
-
-If @var{arg} is non-@code{nil}, it should be a raw prefix argument.
-@code{toggle-read-only} sets @code{buffer-read-only} to @code{t} if
-the numeric value of that prefix argument is positive and to
-@code{nil} otherwise. @xref{Prefix Command Arguments}.
+@deffn Command read-only-mode &optional arg
+This is the mode command for Read Only minor mode, a buffer-local
+minor mode. When the mode is enabled, @code{buffer-read-only} is
+non-@code{nil} in the buffer; when disabled, @code{buffer-read-only}
+is @code{nil} in the buffer. The calling convention is the same as
+for other minor mode commands (@pxref{Minor Mode Conventions}).
+
+This minor mode mainly serves as a wrapper for
+@code{buffer-read-only}; unlike most minor modes, there is no separate
+@code{read-only-mode} variable. Even when Read Only mode is disabled,
+characters with non-@code{nil} @code{read-only} text properties remain
+read-only. To temporarily ignore all read-only states, bind
+@code{inhibit-read-only}, as described above.
+
+When enabling Read Only mode, this mode command also enables View mode
+if the option @code{view-read-only} is non-@code{nil}. @xref{Misc
+Buffer,,Miscellaneous Buffer Operations, emacs, The GNU Emacs Manual}.
+When disabling Read Only mode, it disables View mode if View mode was
+enabled.
@end deffn
@defun barf-if-buffer-read-only
resort. If @var{visible-ok} is non-@code{nil}, then it does not matter
whether a buffer is displayed somewhere or not.
-If no suitable buffer exists, the buffer @samp{*scratch*} is returned
+If no suitable buffer exists, the buffer @file{*scratch*} is returned
(and created, if necessary).
@end defun
The argument @var{visible-ok} is handled as with @code{other-buffer},
see above. If no suitable buffer can be found, the buffer
-@samp{*scratch*} is returned.
+@file{*scratch*} is returned.
@end defun
@deffn Command bury-buffer &optional buffer-or-name
@code{other-buffer} to return. The argument can be either a buffer
itself or the name of one.
-This functions operates on each frame's @code{buffer-list} parameter as
+This function operates on each frame's @code{buffer-list} parameter as
well as the fundamental buffer list; therefore, the buffer that you bury
will come last in the value of @code{(buffer-list @var{frame})} and in
the value of @code{(buffer-list)}. In addition, it also puts the buffer
If @var{buffer-or-name} is @code{nil} or omitted, this means to bury the
current buffer. In addition, if the current buffer is displayed in the
selected window, this makes sure that the window is either deleted or
-another buffer is shown in it. More precisely, if the window is
-dedicated (@pxref{Dedicated Windows}) and there are other windows on its
-frame, the window is deleted. If the window is both dedicated and the
-only window on its frame's terminal, the function specified by
-@code{frame-auto-hide-function} (@pxref{Quitting Windows}) will deal
-with the window. If the window is not dedicated to its buffer, it calls
-@code{switch-to-prev-buffer} (@pxref{Window History}) to show another
-buffer in that window. If @var{buffer-or-name} is displayed in some
-other window, it remains displayed there.
+another buffer is shown in it. More precisely, if the selected window
+is dedicated (@pxref{Dedicated Windows}) and there are other windows on
+its frame, the window is deleted. If it is the only window on its frame
+and that frame is not the only frame on its terminal, the frame is
+``dismissed'' by calling the function specified by
+@code{frame-auto-hide-function} (@pxref{Quitting Windows}). Otherwise,
+it calls @code{switch-to-prev-buffer} (@pxref{Window History}) to show
+another buffer in that window. If @var{buffer-or-name} is displayed in
+some other window, it remains displayed there.
To replace a buffer in all the windows that display it, use
@code{replace-buffer-in-windows}, @xref{Buffers and Windows}.
@defun gap-size
This function returns the current gap size of the current buffer.
@end defun
-
HCoop / bpt / emacs.git / blobdiff