The buffer file name is the name of the file that is visited in
that buffer. When a buffer is not visiting a file, its buffer file name
nil. Most of the time, the buffer name is the same as the
nondirectory part of the buffer file name, but the buffer file name and
the buffer name are distinct and can be set independently.
See Visiting Files.
This function returns the absolute file name of the file that
buffer is visiting. If buffer is not visiting any file,
nil. If buffer is not
supplied, it defaults to the current buffer.
(buffer-file-name (other-buffer)) ⇒ "/usr/user/lewis/manual/files.texi"
This buffer-local variable contains the name of the file being visited
in the current buffer, or
nil if it is not visiting a file. It
is a permanent local variable, unaffected by
buffer-file-name ⇒ "/usr/user/lewis/manual/buffers.texi"
It is risky to change this variable’s value without doing various other
things. Normally it is better to use
below); some of the things done there, such as changing the buffer name,
are not strictly necessary, but others are essential to avoid confusing
This buffer-local variable holds the abbreviated truename of the file
visited in the current buffer, or
nil if no file is visited.
It is a permanent local, unaffected by
kill-all-local-variables. See Truenames, and
This buffer-local variable holds the file number and directory device
number of the file visited in the current buffer, or
nil if no
file or a nonexistent file is visited. It is a permanent local,
The value is normally a list of the form
devnum). This pair of numbers uniquely identifies the file among
all files accessible on the system. See the function
file-attributes, in File Attributes, for more information
buffer-file-name is the name of a symbolic link, then both
numbers refer to the recursive target.
This function returns the buffer visiting file filename. If
there is no such buffer, it returns
nil. The argument
filename, which must be a string, is expanded (see File Name Expansion), then compared against the visited file names of all live
buffers. Note that the buffer’s
buffer-file-name must match
the expansion of filename exactly. This function will not
recognize other names for the same file.
(get-file-buffer "buffers.texi") ⇒ #<buffer buffers.texi>
In unusual circumstances, there can be more than one buffer visiting the same file name. In such cases, this function returns the first such buffer in the buffer list.
find-buffer-visitingfilename &optional predicate
This is like
get-file-buffer, except that it can return any
buffer visiting the file possibly under a different name. That
is, the buffer’s
buffer-file-name does not need to match the
expansion of filename exactly, it only needs to refer to the
same file. If predicate is non-
nil, it should be a
function of one argument, a buffer visiting filename. The
buffer is only considered a suitable return value if predicate
nil. If it can not find a suitable buffer to
set-visited-file-namefilename &optional no-query along-with-file
If filename is a non-empty string, this function changes the name of the file visited in the current buffer to filename. (If the buffer had no visited file, this gives it one.) The next time the buffer is saved it will go in the newly-specified file.
This command marks the buffer as modified, since it does not (as far as Emacs knows) match the contents of filename, even if it matched the former visited file. It also renames the buffer to correspond to the new file name, unless the new name is already in use.
If filename is
nil or the empty string, that stands for
“no visited file”. In this case,
the buffer as having no visited file, without changing the buffer’s
Normally, this function asks the user for confirmation if there
already is a buffer visiting filename. If no-query is
nil, that prevents asking this question. If there already
is a buffer visiting filename, and the user confirms or
no-query is non-
nil, this function makes the new
buffer name unique by appending a number inside of ‘<…>’ to
If along-with-file is non-
nil, that means to assume that
the former visited file has been renamed to 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
visited-file-modtime (see Modification Time). If
nil, this function clears the recorded
last file modification time, after which
When the function
set-visited-file-name is called
interactively, it prompts for filename in the minibuffer.
This buffer-local variable specifies a string to display in a buffer listing where the visited file name would go, for buffers that don’t have a visited file name. Dired buffers use this variable.