;;; uniquify.el --- unique buffer names dependent on file name
;; Copyright (c) 1989, 1995, 1996, 1997 Free Software Foundation, Inc.
;; Author: Dick King <email@example.com>
;; Maintainer: Michael Ernst <firstname.lastname@example.org>
;; Created: 15 May 86
;; Time-stamp: <99/11/11 09:50:44 aj>
;; This file is part of GNU Emacs.
;; GNU Emacs is free software; you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation; either version 2, or (at your option)
;; any later version.
;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;; GNU General Public License for more details.
;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs; see the file COPYING. If not, write to the
;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
;; Boston, MA 02111-1307, USA.
;; Emacs's standard method for making buffer names unique adds <2>, <3>,
;; etc. to the end of (all but one of) the buffers. This file replaces
;; that behavior, for buffers visiting files and dired buffers, with a
;; uniquification that adds parts of the file name until the buffer names
;; are unique. For instance, buffers visiting /u/mernst/tmp/Makefile and
;; /usr/projects/zaphod/Makefile would be named Makefile|tmp and
;; Makefile|zaphod, respectively (instead of Makefile and Makefile<2>).
;; Other buffer name styles are also available.
;; To use this file, load it or add (require 'uniquify) to your ".emacs"
;; and set `uniquify-buffer-name-style' to one of its non-nil alternative
;; For other options, see "User-visible variables", below.
;; A version of uniquify.el that works under Emacs 18, Emacs 19, XEmacs 19,
;; and InfoDock is available from the maintainer.
;; Doesn't work under NT when backslash is used as a path separator (forward
;; slash path separator works fine). To fix, check system-type against
;; 'windows-nt, write a routine that breaks paths down into components.
;; (Surprisingly, there isn't one built in.)
;;; Change Log:
;; Originally by Dick King <email@example.com> 15 May 86
;; Converted for Emacs 18 by Stephen Gildea <firstname.lastname@example.org>
;; Make uniquify-min-dir-content 0 truly non-invasive. gildea 23 May 89
;; Some cleanup. uniquify-min-dir-content default 0. gildea 01 Jun 89
;; Don't rename to "". Michael Ernst <email@example.com> 15 Jun 94
;; Add kill-buffer-hook. Kenneth Manheimer <firstname.lastname@example.org> 09 May 95
;; Add advice for rename-buffer and create-file-buffer, handle dired buffers,
;; kill-buffer-rationalize-buffer-names-p, documentation. mernst 24 May 95
;; Remove free variables, fix typos. mernst 5 Jun 95
;; Efficiently support Emacs 19.27 & earlier. ken.manheimer, mernst 10 Jun 95
;; Rename user options to "uniquify-...", add uniquify-reverse-dir-content-p,
;; add uniquify-ask-about-buffer-names-p. king, mernst 13 Jun 95
;; Prefix functions by "uniquify-..."; rename mnemonic-buffer-names to
;; uniquify-buffer-name-style; add 'forward and 'post-forward-angle-brackets
;; styles; remove uniquify-reverse-dir-content-p; add
;; uniquify-trailing-separator-p. mernst 4 Aug 95
;; Don't call expand-file-name on nil. mernst 7 Jan 96
;; Check whether list-buffers-directory is bound. mernst 11 Oct 96
;; Ignore non-file non-dired buffers. Colin Rafferty <email@example.com> 3 Mar 97
;; Use last component, not "", for file name of directories. mernst 27 Jun 97
;; Use directory-file-name; code cleanup. mernst 6 Sep 97
;; Add uniquify-ignore-buffers-re.
;; Andre Srinivasan <firstname.lastname@example.org> 9 Sep 97
;; Valuable feedback was provided by
;; Paul Smith <email@example.com>,
;; Alastair Burt <firstname.lastname@example.org>,
;; Bob Weiner <email@example.com>,
;; Albert L. Ting <firstname.lastname@example.org>,
;; Bryan O'Sullivan <email@example.com>.
;;; User-visible variables
(defgroup uniquify nil
"Unique buffer names dependent on file name"
(defcustom uniquify-buffer-name-style nil
"*If non-nil, buffer names are uniquified with parts of directory name.
The value determines the buffer name style and is one of `forward',
`reverse', `post-forward' (the default), or `post-forward-angle-brackets'.
For example, files `/foo/bar/mumble/name' and `/baz/quux/mumble/name'
would have the following buffer names in the various styles:
forward bar/mumble/name quux/mumble/name
reverse name\\mumble\\bar name\\mumble\\quux
post-forward name|bar/mumble name|quux/mumble
post-forward-angle-brackets name<bar/mumble> name<quux/mumble>
nil name name<2>"
:type '(radio (const forward)
(const :tag "standard Emacs behavior (nil)" nil))
(defcustom uniquify-after-kill-buffer-p nil
"*If non-nil, rerationalize buffer names after a buffer has been killed.
This can be dangerous if Emacs Lisp code is keeping track of buffers by their
names (rather than keeping pointers to the buffers themselves)."
(defcustom uniquify-ask-about-buffer-names-p nil
"*If non-nil, permit user to choose names for buffers with same base file.
If the user chooses to name a buffer, uniquification is preempted and no
other buffer names are changed."
(defcustom uniquify-ignore-buffers-re nil
"*Regular expression matching buffer names that should not be uniquified.
For instance, set this to \"^draft-[0-9]+$\" to avoid having uniquify rename
draft buffers even if `uniquify-after-kill-buffer-p' is non-nil and the
visited file name isn't the same as that of the buffer."
:type '(choice (const :tag "Uniquify all buffers" nil) regexp)
(defcustom uniquify-min-dir-content 0
"*Minimum number of directory name components included in buffer name."
(defcustom uniquify-separator nil
"*String separator for buffer name components.
When `uniquify-buffer-name-style' is `post-forward', separates
base file name from directory part in buffer names (default \"|\").
When `uniquify-buffer-name-style' is `reverse', separates all
file name components (default \"\\\")."
:type '(choice (const nil) string)
(defcustom uniquify-trailing-separator-p nil
"*If non-nil, add a file name separator to dired buffer names.
If `uniquify-buffer-name-style' is `forward', add the separator at the end;
if it is `reverse', add the separator at the beginning; otherwise, this
variable is ignored."
(defmacro uniquify-push (item list)
(` (setq (, list) (cons (, item) (, list)))))
;; For directories, return the last component, not the empty string.
(defun uniquify-file-name-nondirectory (file-name)
(file-name-nondirectory (directory-file-name file-name)))
;; uniquify-fix-list data structure
(defmacro uniquify-fix-item-base (a)
(` (car (, a))))
(defmacro uniquify-fix-item-filename (a)
(` (car (cdr (, a)))))
(defmacro uniquify-fix-item-buffer (a)
(` (car (cdr (cdr (, a))))))
;; Not a macro: passed to mapcar.
(defun uniquify-fix-item-unrationalized-buffer (item)
(or (car (cdr (cdr (cdr item)))) nil)) ;maybe better in the future
(defun uniquify-fix-item-filename-lessp (fixlist1 fixlist2)
(uniquify-filename-lessp (uniquify-fix-item-filename fixlist1)
;; Internal variables used free
(defvar uniquify-non-file-buffer-names nil)
(defvar uniquify-possibly-resolvable nil)
;;; Main entry point.
(defun uniquify-rationalize-file-buffer-names (&optional newbuffile newbuf)
"Makes file buffer names unique by adding segments from file name.
If `uniquify-min-dir-content' > 0, always pulls that many
file name elements. Arguments cause only a subset of buffers to be renamed."
(let ((buffers (buffer-list)))
(let* ((buffer (car buffers))
(bfn (if (eq buffer newbuf)
(if (file-directory-p newbuffile)
(rawname (and bfn (uniquify-file-name-nondirectory bfn)))
(deserving (and rawname
(not (and uniquify-ignore-buffers-re
(or (not newbuffile)
(uniquify-push (list rawname bfn buffer nil) fix-list)
(uniquify-push (list (buffer-name buffer))
(setq buffers (cdr buffers))))
;; selects buffers whose names may need changing, and others that
;; may conflict.
(sort fix-list 'uniquify-fix-item-filename-lessp))
;; bringing conflicting names together
(uniquify-rationalize-a-list fix-list uniquify-min-dir-content)
(mapcar 'uniquify-fix-item-unrationalized-buffer fix-list)))
;; uniquify's version of buffer-file-name; result never contains trailing slash
(defun uniquify-buffer-file-name (buffer)
"Return name of file BUFFER is visiting, or nil if none.
Works on dired buffers and ordinary file-visiting buffers, but no others."
(or (buffer-file-name buffer)
(and (featurep 'dired)
(eq major-mode 'dired-mode) ; do nothing if not a dired buffer
(if (boundp 'list-buffers-directory) ; (XEmacs does define this!)
;; don't use default-directory if dired-directory is nil
(if (consp dired-directory)
;; This examines the filename components in reverse order.
(defun uniquify-filename-lessp (s1 s2)
(let ((s1f (uniquify-file-name-nondirectory s1))
(s2f (uniquify-file-name-nondirectory s2)))
(and (not (equal s2f ""))
(or (string-lessp s1f s2f)
(and (equal s1f s2f)
(let ((s1d (file-name-directory s1))
(s2d (file-name-directory s2)))
(and (not (<= (length s2d) 1))
(or (<= (length s1d) 1)
(substring s1d 0 -1)
(substring s2d 0 -1))))))))))
(defun uniquify-rationalize-a-list (fix-list depth)
(let (conflicting-sublist ; all elements have the same proposed name
(let ((item (car fix-list)))
(setq proposed-name (uniquify-get-proposed-name item depth))
(if (not (equal proposed-name old-name))
conflicting-sublist old-name depth)
(setq conflicting-sublist nil)))
(uniquify-push item conflicting-sublist)
(setq old-name proposed-name))
(setq fix-list (cdr fix-list)))
conflicting-sublist old-name depth)))
(defun uniquify-get-proposed-name (item depth)
(base (uniquify-fix-item-base item))
(fn (uniquify-fix-item-filename item)))
(while (and (> n 0)
(setq index (string-match
(setq extra-string (substring fn
(if (zerop index) 0 (1+ index))
;; (- (length base)) fails for base = "".
;; Equivalently, we could have used
;; (apply 'substring ...
;; (and (not (string= "" base))
;; (list (- (length base)))))
(- (length fn) (length base)))
n (1- n)))
(if (zerop n) (setq uniquify-possibly-resolvable t))
;; Distinguish directories by adding extra separator.
(if (and uniquify-trailing-separator-p
(not (string-equal base "")))
(cond ((eq uniquify-buffer-name-style 'forward)
(setq base (concat base "/")))
((eq uniquify-buffer-name-style 'reverse)
(setq base (concat (or uniquify-separator "\\") base)))))
;; Trim trailing separator on directory part
(if (and (not (string-equal extra-string ""))
(or (eq uniquify-buffer-name-style 'post-forward)
(eq uniquify-buffer-name-style 'post-forward-angle-brackets)))
(setq extra-string (substring extra-string 0
(- (length extra-string) 1))))
(cond ((string-equal extra-string "")
((string-equal base "")
((eq uniquify-buffer-name-style 'forward)
(concat extra-string base))
((eq uniquify-buffer-name-style 'reverse)
(concat base (uniquify-reverse-components extra-string)))
((eq uniquify-buffer-name-style 'post-forward)
(concat base (or uniquify-separator "|") extra-string))
((eq uniquify-buffer-name-style 'post-forward-angle-brackets)
(concat base "<" extra-string ">"))
(t (error "Bad value for uniquify-buffer-name-style: %s"
;; Deal with conflicting-sublist, all of whose elements have identical
;; "base" components.
(defun uniquify-rationalize-conflicting-sublist (conflicting-sublist old-name depth)
(or (null conflicting-sublist)
(and (null (cdr conflicting-sublist))
(not (assoc old-name uniquify-non-file-buffer-names))
(or (and (not (string= old-name ""))
(uniquify-rename-buffer (car conflicting-sublist) old-name))
(uniquify-rationalize-a-list conflicting-sublist (1+ depth)))))
(defun uniquify-rename-buffer (item newname)
(let ((buffer (uniquify-fix-item-buffer item)))
(if (not (equal newname (buffer-name buffer)))
(let ((unset (current-buffer))
;; avoid hooks on rename-buffer
(rplaca (nthcdr 3 item) t))
(defun uniquify-reverse-components (instring)
(let ((sofar '())
(len (length instring))
(sep (or uniquify-separator "\\")))
(while (< cursor len)
(if (= (aref instring cursor) ?/)
(setq sofar (cons sep sofar)
cursor (1+ cursor))
(let ((first-slash (or (string-match "/" instring cursor) len)))
(setq sofar (cons (substring instring cursor first-slash) sofar)
(apply (function concat) sofar)))
;;; Hooks from the rest of Emacs
;; The logical place to put all this code is in generate-new-buffer-name.
;; It's written in C, so we would add a generate-new-buffer-name-function
;; which, if non-nil, would be called instead of the C. One problem with
;; that is that generate-new-buffer-name takes a potential buffer name as
;; its argument -- not other information, such as what file the buffer will
;; The below solution works because generate-new-buffer-name is called
;; only by rename-buffer (which, as of 19.29, is never called from C) and
;; generate-new-buffer, which is called only by Lisp functions
;; create-file-buffer and rename-uniquely. Rename-uniquely generally
;; isn't used for buffers visiting files, so it's sufficient to hook
;; rename-buffer and create-file-buffer. (Setting find-file-hooks isn't
(defadvice rename-buffer (after rename-buffer-uniquify activate)
"Uniquify buffer names with parts of directory name."
(if (and uniquify-buffer-name-style
;; UNIQUE argument
;; call with no argument; rationalize vs. old name as well as new
;; call with argument: rationalize vs. new name only
(uniquify-buffer-file-name (current-buffer)) (current-buffer)))
(setq ad-return-value (buffer-name (current-buffer))))))
(defadvice create-file-buffer (after create-file-buffer-uniquify activate)
"Uniquify buffer names with parts of directory name."
(uniquify-rationalize-file-buffer-names (ad-get-arg 0) ad-return-value)))
;; Buffer deletion
;; Rerationalize after a buffer is killed, to reduce coinciding buffer names.
;; This mechanism uses `kill-buffer-hook', which runs *before* deletion.
;; That means that the kill-buffer-hook function cannot just delete the
;; buffer -- it has to set something to do the rationalization *later*.
;; It actually puts another function on `post-command-hook'. This other
;; function runs the rationalization and then removes itself from the hook.
;; Is there a better way to accomplish this?
;; (This ought to set some global variables so the work is done only for
;; buffers with names similar to the deleted buffer. -MDE)
(defun delay-uniquify-rationalize-file-buffer-names ()
"Add `delayed-uniquify-rationalize-file-buffer-names' to `post-command-hook'.
For use on, eg, `kill-buffer-hook', to rationalize *after* buffer deletion."
(if (and uniquify-buffer-name-style
(defun delayed-uniquify-rationalize-file-buffer-names ()
"Rerationalize buffer names and remove self from `post-command-hook'.
See also `delay-rationalize-file-buffer-names' for hook setter."
(add-hook 'kill-buffer-hook 'delay-uniquify-rationalize-file-buffer-names)
;;; uniquify.el ends here