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Various changes in addition to:

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(Buffer File Name): Add `find-buffer-visiting'.
(Buffer Modification): Mention optional ARG to `not-modified'.
(Indirect Buffers): Mention optional CLONE argument to `make-indirect-buffer'.
This commit is contained in:
Luc Teirlinck 2004-04-14 02:48:08 +00:00
parent 19efcb4634
commit 619fb950d6
2 changed files with 162 additions and 58 deletions
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17
lispref/ChangeLog
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@ -1,3 +1,20 @@
2004-04-13 Luc Teirlinck <teirllm@auburn.edu>
* buffers.texi: Various changes in addition to:
(Buffer File Name): Add `find-buffer-visiting'.
(Buffer Modification): Mention optional ARG to `not-modified'.
(Indirect Buffers): Mention optional CLONE argument to
`make-indirect-buffer'.
* files.texi: Various changes in addition to:
(Visiting Functions): `find-file-hook' is now a normal hook.
(File Name Expansion): Explain difference between the way that
`expand-file-name' and `file-truename' treat `..'.
(Contents of Directories): Mention optional ID-FORMAT argument to
`directory-files-and-attributes'.
(Format Conversion): Mention new optional CONFIRM argument to
`format-write-file'.
2004-04-12 Miles Bader <miles@gnu.org>
* macros.texi (Expansion): Add description of `macroexpand-all'.

203
lispref/buffers.texi
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@ -215,12 +215,16 @@ of course. Instead, whichever buffer was current just before exit
remains current.
@end defspec
@defmac with-current-buffer buffer body...
@defmac with-current-buffer buffer-or-name body...
The @code{with-current-buffer} macro saves the identity of the current
buffer, makes @var{buffer} current, evaluates the @var{body} forms, and
finally restores the buffer. The return value is the value of the last
form in @var{body}. The current buffer is restored even in case of an
abnormal exit via @code{throw} or error (@pxref{Nonlocal Exits}).
buffer, makes @var{buffer-or-name} current, evaluates the @var{body}
forms, and finally restores the buffer. The return value is the value
of the last form in @var{body}. The current buffer is restored even
in case of an abnormal exit via @code{throw} or error (@pxref{Nonlocal
Exits}).
An error is signaled if @var{buffer-or-name} does not identify an
existing buffer.
@end defmac
@anchor{Definition of with-temp-buffer}
@ -237,9 +241,10 @@ return the contents of the temporary buffer by using
The current buffer is restored even in case of an abnormal exit via
@code{throw} or error (@pxref{Nonlocal Exits}).
@end defmac
See also @code{with-temp-file} in @ref{Writing to Files}.
See also @code{with-temp-file} in @ref{Definition of with-temp-file,,
Writing to Files}.
@end defmac
@node Buffer Names
@section Buffer Names
@ -293,8 +298,7 @@ foo
@deffn Command rename-buffer newname &optional unique
This function renames the current buffer to @var{newname}. An error
is signaled if @var{newname} is not a string, or if there is already a
buffer with that name. The function returns @var{newname}.
is signaled if @var{newname} is not a string.
@c Emacs 19 feature
Ordinarily, @code{rename-buffer} signals an error if @var{newname} is
@ -302,6 +306,8 @@ already in use. However, if @var{unique} is non-@code{nil}, it modifies
@var{newname} to make a name that is not in use. Interactively, you can
make @var{unique} non-@code{nil} with a numeric prefix argument.
(This is how the command @code{rename-uniquely} is implemented.)
This function returns the name actually given to the buffer.
@end deffn
@defun get-buffer buffer-or-name
@ -330,11 +336,12 @@ See also the function @code{get-buffer-create} in @ref{Creating Buffers}.
@end defun
@c Emacs 19 feature
@defun generate-new-buffer-name starting-name &rest ignore
@defun generate-new-buffer-name starting-name &optional ignore
This function returns a name that would be unique for a new buffer---but
does not create the buffer. It starts with @var{starting-name}, and
produces a name not currently in use for any buffer by appending a
number inside of @samp{<@dots{}>}.
number inside of @samp{<@dots{}>}. It starts at 2 and keeps
incrementing the number until it is not the name of an existing buffer.
If the optional second argument @var{ignore} is non-@code{nil}, it
should be a string; it makes a difference if it is a name in the
@ -404,9 +411,11 @@ Emacs.
@end defvar
@defvar buffer-file-truename
This buffer-local variable holds the truename of the file visited in the
current buffer, or @code{nil} if no file is visited. It is a permanent
local, unaffected by @code{kill-all-local-variables}. @xref{Truenames}.
This buffer-local variable holds the abbreviated truename of the file
visited in the current buffer, or @code{nil} if no file is visited.
It is a permanent local, unaffected by
@code{kill-all-local-variables}. @xref{Truenames}, and
@ref{Definition of abbreviate-file-name}.
@end defvar
@defvar buffer-file-number
@ -420,6 +429,9 @@ The value is normally a list of the form @code{(@var{filenum}
all files accessible on the system. See the function
@code{file-attributes}, in @ref{File Attributes}, for more information
about them.
If @code{buffer-file-name} is the name of a symbolic link, then both
numbers refer to the recursive target.
@end defvar
@defun get-file-buffer filename
@ -427,7 +439,9 @@ This function returns the buffer visiting file @var{filename}. If
there is no such buffer, it returns @code{nil}. The argument
@var{filename}, which must be a string, is expanded (@pxref{File Name
Expansion}), then compared against the visited file names of all live
buffers.
buffers. Note that the buffer's @code{buffer-file-name} must match
the expansion of @var{filename} exactly. This function will not
recognize other names for the same file.
@example
@group
@ -441,6 +455,18 @@ the same file name. In such cases, this function returns the first
such buffer in the buffer list.
@end defun
@defun find-buffer-visiting filename &optional predicate
This is like @code{get-file-buffer}, except that it can return any
buffer visiting the file @emph{possibly under a different name}. That
is, the buffer's @code{buffer-file-name} does not need to match the
expansion of @var{filename} exactly, it only needs to refer to the
same file. If @var{predicate} is non-@code{nil}, it should be a
function of one argument, a buffer visiting @var{filename}. The
buffer is only considered a suitable return value if @var{predicate}
returns non-@code{nil}. If it can not find a suitable buffer to
return, @code{find-buffer-visiting} returns @code{nil}.
@end defun
@deffn Command set-visited-file-name filename &optional no-query along-with-file
If @var{filename} is a non-empty string, this function changes the
name of the file visited in the current buffer to @var{filename}. (If the
@ -455,14 +481,24 @@ 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
the buffer as having no visited file.
the buffer as having no visited file, without changing the buffer's
modified flag.
Normally, this function asks the user for confirmation if the specified
file already exists. If @var{no-query} is non-@code{nil}, that prevents
asking this question.
Normally, this function asks the user for confirmation if there
already is a buffer visiting @var{filename}. If @var{no-query} is
non-@code{nil}, that prevents asking this question. If there already
is a buffer visiting @var{filename}, and the user confirms or
@var{query} is non-@code{nil}, this function makes the new buffer name
unique by appending a number inside of @samp{<@dots{}>} to @var{filename}.
If @var{along-with-file} is non-@code{nil}, that means to assume that the
former visited file has been renamed to @var{filename}.
If @var{along-with-file} is non-@code{nil}, that means to assume that
the former visited file has been renamed to @var{filename}. In this
case, the command does not change the buffer's modified flag, nor the
buffer's recorded last file modification time as reported by
@code{visited-file-modtime} (@pxref{Modification Time}). If
@var{along-with-file} is @code{nil}, this function clears the recorded
last file modification time, after which @code{visited-file-modtime}
returns zero.
@c Wordy to avoid overfull hbox. --rjc 16mar92
When the function @code{set-visited-file-name} is called interactively, it
@ -523,10 +559,11 @@ Like @code{set-buffer-modified-p}, but does not force redisplay
of mode lines.
@end defun
@deffn Command not-modified
This command marks the current buffer as unmodified, and not needing to
be saved. With prefix arg, it marks the buffer as modified, so that it
will be saved at the next suitable occasion.
@deffn Command not-modified &optional arg
This command marks the current buffer as unmodified, and not needing
to be saved. If @var{arg} is non-@code{nil}, it marks the buffer as
modified, so that it will be saved at the next suitable occasion.
Interactively, @var{arg} is the prefix argument.
Don't use this function in programs, since it prints a message in the
echo area; use @code{set-buffer-modified-p} (above) instead.
@ -537,6 +574,7 @@ echo area; use @code{set-buffer-modified-p} (above) instead.
This function returns @var{buffer}'s modification-count. This is a
counter that increments every time the buffer is modified. If
@var{buffer} is @code{nil} (or omitted), the current buffer is used.
The counter can wrap around occasionally.
@end defun
@node Modification Time
@ -561,6 +599,16 @@ visited or saved it.
The function returns @code{t} if the last actual modification time and
Emacs's recorded modification time are the same, @code{nil} otherwise.
It also returns @code{t} if the buffer has no recorded last
modification time, that is if @code{visited-file-modtime} would return
zero.
It always returns @code{t} for buffers that are not visiting a file,
even if @code{visited-file-modtime} returns a non-zero value. For
instance, it always returns @code{t} for dired buffers. It returns
@code{t} for buffers that are visiting a file that does not exist and
never existed, but @code{nil} for file-visiting buffers whose file has
been deleted.
@end defun
@defun clear-visited-file-modtime
@ -576,10 +624,30 @@ file should not be done.
@c Emacs 19 feature
@defun visited-file-modtime
This function returns the buffer's recorded last file modification time,
as a list of the form @code{(@var{high} . @var{low})}. (This is the
same format that @code{file-attributes} uses to return time values; see
@ref{File Attributes}.)
This function returns the current buffer's recorded last file
modification time, as a list of the form @code{(@var{high} .
@var{low})}. (This is the same format that @code{file-attributes}
uses to return time values; see @ref{File Attributes}.)
The function returns zero if the buffer has no recorded last
modification time, which can happen, for instance, if the record has
been explicitly cleared by @code{clear-visited-file-modtime} or if the
buffer is not visiting a file. Note, however, that
@code{visited-file-modtime} can return a non-zero value for some
buffers that are not visiting files, but are nevertheless closely
associated with a file. This happens, for instance, with dired
buffers listing a directory. For such buffers,
@code{visited-file-modtime} returns the last modification time of that
directory, as recorded by dired.
For a new buffer visiting a not yet existing file, @var{high} is
@minus{}1 and @var{low} is 65535, that is,
@ifnottex
@w{2**16 - 1.}
@end ifnottex
@tex
@math{2^{16}-1}.
@end tex
@end defun
@c Emacs 19 feature
@ -589,7 +657,7 @@ of the visited file, to the value specified by @var{time} if @var{time}
is not @code{nil}, and otherwise to the last modification time of the
visited file.
If @var{time} is not @code{nil}, it should have the form
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.
@ -655,12 +723,13 @@ The buffer is read-only if this variable is non-@code{nil}.
@end defvar
@defvar inhibit-read-only
If this variable is non-@code{nil}, then read-only buffers and 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.
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.
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
@ -816,12 +885,14 @@ buffer and gives it a unique name.
subprocess can also create a buffer (@pxref{Processes}).
@defun get-buffer-create name
This function returns a buffer named @var{name}. It returns an existing
This function returns a buffer named @var{name}. It returns a live
buffer with that name, if one exists; otherwise, it creates a new
buffer. The buffer does not become the current buffer---this function
does not change which buffer is current.
An error is signaled if @var{name} is not a string.
If @var{name} is a buffer instead of a string, it is returned, even if
it is dead. An error is signaled if @var{name} is neither a string
nor a buffer.
@example
@group
@ -830,8 +901,8 @@ An error is signaled if @var{name} is not a string.
@end group
@end example
The major mode for the new buffer is set to Fundamental mode. The
variable @code{default-major-mode} is handled at a higher level.
The major mode for a newly created buffer is set to Fundamental mode.
The variable @code{default-major-mode} is handled at a higher level.
@xref{Auto Major Mode}.
@end defun
@ -905,8 +976,8 @@ this feature to test whether a buffer has been killed:
@deffn Command kill-buffer buffer-or-name
This function kills the buffer @var{buffer-or-name}, freeing all its
memory for other uses or to be returned to the operating system. It
returns @code{nil}.
memory for other uses or to be returned to the operating system. If
@var{buffer-or-name} is @code{nil}, it kills the current buffer.
Any processes that have this buffer as the @code{process-buffer} are
sent the @code{SIGHUP} signal, which normally causes them to terminate.
@ -921,16 +992,20 @@ for confirmation, clear the modified flag before calling
Killing a buffer that is already dead has no effect.
This function returns @code{t} if it actually killed the buffer. It
returns @code{nil} if the user refuses to confirm or if
@var{buffer-or-name} was already dead.
@smallexample
(kill-buffer "foo.unchanged")
@result{} nil
@result{} t
(kill-buffer "foo.changed")
---------- Buffer: Minibuffer ----------
Buffer foo.changed modified; kill anyway? (yes or no) @kbd{yes}
---------- Buffer: Minibuffer ----------
@result{} nil
@result{} t
@end smallexample
@end deffn
@ -953,13 +1028,15 @@ is not cleared by changing major modes.
@defvar buffer-offer-save
This variable, if non-@code{nil} in a particular buffer, tells
@code{save-buffers-kill-emacs} and @code{save-some-buffers} to offer to
save that buffer, just as they offer to save file-visiting buffers. The
variable @code{buffer-offer-save} automatically becomes buffer-local
when set for any reason. @xref{Buffer-Local Variables}.
@code{save-buffers-kill-emacs} and @code{save-some-buffers} (if the
second optional argument to that function is @code{t}) to offer to
save that buffer, just as they offer to save file-visiting buffers.
@xref{Definition of save-some-buffers}. The variable
@code{buffer-offer-save} automatically becomes buffer-local when set
for any reason. @xref{Buffer-Local Variables}.
@end defvar
@defun buffer-live-p buffer
@defun buffer-live-p object
This function returns @code{t} if @var{object} is a buffer which has
not been killed, @code{nil} otherwise.
@end defun
@ -994,19 +1071,29 @@ buffer.
the base buffer effectively kills the indirect buffer in that it cannot
ever again be the current buffer.
@deffn Command make-indirect-buffer base-buffer name
This creates an indirect buffer named @var{name} whose base buffer
is @var{base-buffer}. The argument @var{base-buffer} may be a buffer
or a string.
@deffn Command make-indirect-buffer base-buffer name &optional clone
This creates and returns an indirect buffer named @var{name} whose
base buffer is @var{base-buffer}. The argument @var{base-buffer} may
be a live buffer or the name (a string) of an existing buffer. If
@var{name} is the name of an existing buffer, an error is signaled.
If @var{clone} is non-@code{nil}, then the indirect buffer originally
shares the ``state'' of @var{base-buffer} such as major mode, minor
modes, buffer local variables and so on. If @var{clone} is omitted
or @code{nil} the indirect buffer's state is set to the default state
for new buffers.
If @var{base-buffer} is an indirect buffer, its base buffer is used as
the base for the new buffer.
the base for the new buffer. If, in addition, @var{clone} is
non-@code{nil}, the initial state is copied from the actual base
buffer, not from @var{base-buffer}.
@end deffn
@defun buffer-base-buffer buffer
This function returns the base buffer of @var{buffer}. If @var{buffer}
is not indirect, the value is @code{nil}. Otherwise, the value is
another buffer, which is never an indirect buffer.
@defun buffer-base-buffer &optional buffer
This function returns the base buffer of @var{buffer}, which defaults
to the current buffer. If @var{buffer} is not indirect, the value is
@code{nil}. Otherwise, the value is another buffer, which is never an
indirect buffer.
@end defun
@node Buffer Gap