1;;; files.el --- file input and output commands for Emacs
2
3;; Copyright (C) 1985, 1986, 1987, 1992, 1993, 1994, 1995, 1996,
4;;   1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
5;;   2006, 2007 Free Software Foundation, Inc.
6
7;; Maintainer: FSF
8
9;; This file is part of GNU Emacs.
10
11;; GNU Emacs is free software; you can redistribute it and/or modify
12;; it under the terms of the GNU General Public License as published by
13;; the Free Software Foundation; either version 2, or (at your option)
14;; any later version.
15
16;; GNU Emacs is distributed in the hope that it will be useful,
17;; but WITHOUT ANY WARRANTY; without even the implied warranty of
18;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
19;; GNU General Public License for more details.
20
21;; You should have received a copy of the GNU General Public License
22;; along with GNU Emacs; see the file COPYING.  If not, write to the
23;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
24;; Boston, MA 02110-1301, USA.
25
26;;; Commentary:
27
28;; Defines most of Emacs's file- and directory-handling functions,
29;; including basic file visiting, backup generation, link handling,
30;; ITS-id version control, load- and write-hook handling, and the like.
31
32;;; Code:
33
34(defvar font-lock-keywords)
35
36
37(defgroup backup nil
38  "Backups of edited data files."
39  :group 'files)
40
41(defgroup find-file nil
42  "Finding files."
43  :group 'files)
44
45
46(defcustom delete-auto-save-files t
47  "Non-nil means delete auto-save file when a buffer is saved or killed.
48
49Note that the auto-save file will not be deleted if the buffer is killed
50when it has unsaved changes."
51  :type 'boolean
52  :group 'auto-save)
53
54(defcustom directory-abbrev-alist
55  nil
56  "Alist of abbreviations for file directories.
57A list of elements of the form (FROM . TO), each meaning to replace
58FROM with TO when it appears in a directory name.  This replacement is
59done when setting up the default directory of a newly visited file.
60*Every* FROM string should start with `^'.
61
62Do not use `~' in the TO strings.
63They should be ordinary absolute directory names.
64
65Use this feature when you have directories which you normally refer to
66via absolute symbolic links.  Make TO the name of the link, and FROM
67the name it is linked to."
68  :type '(repeat (cons :format "%v"
69		       :value ("" . "")
70		       (regexp :tag "From")
71		       (regexp :tag "To")))
72  :group 'abbrev
73  :group 'find-file)
74
75;; Turn off backup files on VMS since it has version numbers.
76(defcustom make-backup-files (not (eq system-type 'vax-vms))
77  "Non-nil means make a backup of a file the first time it is saved.
78This can be done by renaming the file or by copying.
79
80Renaming means that Emacs renames the existing file so that it is a
81backup file, then writes the buffer into a new file.  Any other names
82that the old file had will now refer to the backup file.  The new file
83is owned by you and its group is defaulted.
84
85Copying means that Emacs copies the existing file into the backup
86file, then writes the buffer on top of the existing file.  Any other
87names that the old file had will now refer to the new (edited) file.
88The file's owner and group are unchanged.
89
90The choice of renaming or copying is controlled by the variables
91`backup-by-copying', `backup-by-copying-when-linked',
92`backup-by-copying-when-mismatch' and
93`backup-by-copying-when-privileged-mismatch'.  See also `backup-inhibited'."
94  :type 'boolean
95  :group 'backup)
96
97;; Do this so that local variables based on the file name
98;; are not overridden by the major mode.
99(defvar backup-inhibited nil
100  "Non-nil means don't make a backup, regardless of the other parameters.
101This variable is intended for use by making it local to a buffer.
102But it is local only if you make it local.")
103(put 'backup-inhibited 'permanent-local t)
104
105(defcustom backup-by-copying nil
106 "Non-nil means always use copying to create backup files.
107See documentation of variable `make-backup-files'."
108 :type 'boolean
109 :group 'backup)
110
111(defcustom backup-by-copying-when-linked nil
112 "Non-nil means use copying to create backups for files with multiple names.
113This causes the alternate names to refer to the latest version as edited.
114This variable is relevant only if `backup-by-copying' is nil."
115 :type 'boolean
116 :group 'backup)
117
118(defcustom backup-by-copying-when-mismatch nil
119  "Non-nil means create backups by copying if this preserves owner or group.
120Renaming may still be used (subject to control of other variables)
121when it would not result in changing the owner or group of the file;
122that is, for files which are owned by you and whose group matches
123the default for a new file created there by you.
124This variable is relevant only if `backup-by-copying' is nil."
125  :type 'boolean
126  :group 'backup)
127
128(defcustom backup-by-copying-when-privileged-mismatch 200
129  "Non-nil means create backups by copying to preserve a privileged owner.
130Renaming may still be used (subject to control of other variables)
131when it would not result in changing the owner of the file or if the owner
132has a user id greater than the value of this variable.  This is useful
133when low-numbered uid's are used for special system users (such as root)
134that must maintain ownership of certain files.
135This variable is relevant only if `backup-by-copying' and
136`backup-by-copying-when-mismatch' are nil."
137  :type '(choice (const nil) integer)
138  :group 'backup)
139
140(defvar backup-enable-predicate 'normal-backup-enable-predicate
141  "Predicate that looks at a file name and decides whether to make backups.
142Called with an absolute file name as argument, it returns t to enable backup.")
143
144(defcustom buffer-offer-save nil
145  "Non-nil in a buffer means always offer to save buffer on exit.
146Do so even if the buffer is not visiting a file.
147Automatically local in all buffers."
148  :type 'boolean
149  :group 'backup)
150(make-variable-buffer-local 'buffer-offer-save)
151
152(defcustom find-file-existing-other-name t
153  "Non-nil means find a file under alternative names, in existing buffers.
154This means if any existing buffer is visiting the file you want
155under another name, you get the existing buffer instead of a new buffer."
156  :type 'boolean
157  :group 'find-file)
158
159(defcustom find-file-visit-truename nil
160  "*Non-nil means visit a file under its truename.
161The truename of a file is found by chasing all links
162both at the file level and at the levels of the containing directories."
163  :type 'boolean
164  :group 'find-file)
165(put 'find-file-visit-truename 'safe-local-variable 'boolean)
166
167(defcustom revert-without-query nil
168  "Specify which files should be reverted without query.
169The value is a list of regular expressions.
170If the file name matches one of these regular expressions,
171then `revert-buffer' reverts the file without querying
172if the file has changed on disk and you have not edited the buffer."
173  :type '(repeat regexp)
174  :group 'find-file)
175
176(defvar buffer-file-number nil
177  "The device number and file number of the file visited in the current buffer.
178The value is a list of the form (FILENUM DEVNUM).
179This pair of numbers uniquely identifies the file.
180If the buffer is visiting a new file, the value is nil.")
181(make-variable-buffer-local 'buffer-file-number)
182(put 'buffer-file-number 'permanent-local t)
183
184(defvar buffer-file-numbers-unique (not (memq system-type '(windows-nt)))
185  "Non-nil means that `buffer-file-number' uniquely identifies files.")
186
187(defvar buffer-file-read-only nil
188  "Non-nil if visited file was read-only when visited.")
189(make-variable-buffer-local 'buffer-file-read-only)
190
191(defcustom temporary-file-directory
192  (file-name-as-directory
193   (cond ((memq system-type '(ms-dos windows-nt))
194	  (or (getenv "TEMP") (getenv "TMPDIR") (getenv "TMP") "c:/temp"))
195	 ((memq system-type '(vax-vms axp-vms))
196	  (or (getenv "TMPDIR") (getenv "TMP") (getenv "TEMP") "SYS$SCRATCH:"))
197	 (t
198	  (or (getenv "TMPDIR") (getenv "TMP") (getenv "TEMP") "/tmp"))))
199  "The directory for writing temporary files."
200  :group 'files
201  :type 'directory)
202
203(defcustom small-temporary-file-directory
204  (if (eq system-type 'ms-dos) (getenv "TMPDIR"))
205  "The directory for writing small temporary files.
206If non-nil, this directory is used instead of `temporary-file-directory'
207by programs that create small temporary files.  This is for systems that
208have fast storage with limited space, such as a RAM disk."
209  :group 'files
210  :type '(choice (const nil) directory))
211
212;; The system null device. (Should reference NULL_DEVICE from C.)
213(defvar null-device "/dev/null" "The system null device.")
214
215(defvar file-name-invalid-regexp
216  (cond ((and (eq system-type 'ms-dos) (not (msdos-long-file-names)))
217	 (concat "^\\([^A-Z[-`a-z]\\|..+\\)?:\\|" ; colon except after drive
218		 "[+, ;=|<>\"?*]\\|\\[\\|\\]\\|"  ; invalid characters
219		 "[\000-\031]\\|"		  ; control characters
220		 "\\(/\\.\\.?[^/]\\)\\|"	  ; leading dots
221		 "\\(/[^/.]+\\.[^/.]*\\.\\)"))	  ; more than a single dot
222	((memq system-type '(ms-dos windows-nt cygwin))
223	 (concat "^\\([^A-Z[-`a-z]\\|..+\\)?:\\|" ; colon except after drive
224		 "[|<>\"?*\000-\031]"))		  ; invalid characters
225	(t "[\000]"))
226  "Regexp recognizing file names which aren't allowed by the filesystem.")
227
228(defcustom file-precious-flag nil
229  "Non-nil means protect against I/O errors while saving files.
230Some modes set this non-nil in particular buffers.
231
232This feature works by writing the new contents into a temporary file
233and then renaming the temporary file to replace the original.
234In this way, any I/O error in writing leaves the original untouched,
235and there is never any instant where the file is nonexistent.
236
237Note that this feature forces backups to be made by copying.
238Yet, at the same time, saving a precious file
239breaks any hard links between it and other files."
240  :type 'boolean
241  :group 'backup)
242
243(defcustom version-control nil
244  "Control use of version numbers for backup files.
245When t, make numeric backup versions unconditionally.
246When nil, make them for files that have some already.
247The value `never' means do not make them."
248  :type '(choice (const :tag "Never" never)
249		 (const :tag "If existing" nil)
250		 (other :tag "Always" t))
251  :group 'backup
252  :group 'vc)
253(put 'version-control 'safe-local-variable
254     '(lambda (x) (or (booleanp x) (equal x 'never))))
255
256(defcustom dired-kept-versions 2
257  "When cleaning directory, number of versions to keep."
258  :type 'integer
259  :group 'backup
260  :group 'dired)
261
262(defcustom delete-old-versions nil
263  "If t, delete excess backup versions silently.
264If nil, ask confirmation.  Any other value prevents any trimming."
265  :type '(choice (const :tag "Delete" t)
266		 (const :tag "Ask" nil)
267		 (other :tag "Leave" other))
268  :group 'backup)
269
270(defcustom kept-old-versions 2
271  "Number of oldest versions to keep when a new numbered backup is made."
272  :type 'integer
273  :group 'backup)
274(put 'kept-old-versions 'safe-local-variable 'integerp)
275
276(defcustom kept-new-versions 2
277  "Number of newest versions to keep when a new numbered backup is made.
278Includes the new backup.  Must be > 0"
279  :type 'integer
280  :group 'backup)
281(put 'kept-new-versions 'safe-local-variable 'integerp)
282
283(defcustom require-final-newline nil
284  "Whether to add a newline automatically at the end of the file.
285
286A value of t means do this only when the file is about to be saved.
287A value of `visit' means do this right after the file is visited.
288A value of `visit-save' means do it at both of those times.
289Any other non-nil value means ask user whether to add a newline, when saving.
290A value of nil means don't add newlines.
291
292Certain major modes set this locally to the value obtained
293from `mode-require-final-newline'."
294  :type '(choice (const :tag "When visiting" visit)
295		 (const :tag "When saving" t)
296		 (const :tag "When visiting or saving" visit-save)
297		 (const :tag "Don't add newlines" nil)
298		 (other :tag "Ask each time" ask))
299  :group 'editing-basics)
300
301(defcustom mode-require-final-newline t
302  "Whether to add a newline at end of file, in certain major modes.
303Those modes set `require-final-newline' to this value when you enable them.
304They do so because they are often used for files that are supposed
305to end in newlines, and the question is how to arrange that.
306
307A value of t means do this only when the file is about to be saved.
308A value of `visit' means do this right after the file is visited.
309A value of `visit-save' means do it at both of those times.
310Any other non-nil value means ask user whether to add a newline, when saving.
311
312A value of nil means do not add newlines.  That is a risky choice in this
313variable since this value is used for modes for files that ought to have
314final newlines.  So if you set this to nil, you must explicitly check and
315add a final newline, whenever you save a file that really needs one."
316  :type '(choice (const :tag "When visiting" visit)
317		 (const :tag "When saving" t)
318		 (const :tag "When visiting or saving" visit-save)
319		 (const :tag "Don't add newlines" nil)
320		 (other :tag "Ask each time" ask))
321  :group 'editing-basics
322  :version "22.1")
323
324(defcustom auto-save-default t
325  "Non-nil says by default do auto-saving of every file-visiting buffer."
326  :type 'boolean
327  :group 'auto-save)
328
329(defcustom auto-save-visited-file-name nil
330  "Non-nil says auto-save a buffer in the file it is visiting, when practical.
331Normally auto-save files are written under other names."
332  :type 'boolean
333  :group 'auto-save)
334
335(defcustom auto-save-file-name-transforms
336  `(("\\`/[^/]*:\\([^/]*/\\)*\\([^/]*\\)\\'"
337     ;; Don't put "\\2" inside expand-file-name, since it will be
338     ;; transformed to "/2" on DOS/Windows.
339     ,(concat temporary-file-directory "\\2") t))
340  "Transforms to apply to buffer file name before making auto-save file name.
341Each transform is a list (REGEXP REPLACEMENT UNIQUIFY):
342REGEXP is a regular expression to match against the file name.
343If it matches, `replace-match' is used to replace the
344matching part with REPLACEMENT.
345If the optional element UNIQUIFY is non-nil, the auto-save file name is
346constructed by taking the directory part of the replaced file-name,
347concatenated with the buffer file name with all directory separators
348changed to `!' to prevent clashes.  This will not work
349correctly if your filesystem truncates the resulting name.
350
351All the transforms in the list are tried, in the order they are listed.
352When one transform applies, its result is final;
353no further transforms are tried.
354
355The default value is set up to put the auto-save file into the
356temporary directory (see the variable `temporary-file-directory') for
357editing a remote file.
358
359On MS-DOS filesystems without long names this variable is always
360ignored."
361  :group 'auto-save
362  :type '(repeat (list (string :tag "Regexp") (string :tag "Replacement")
363					   (boolean :tag "Uniquify")))
364  :version "21.1")
365
366(defcustom save-abbrevs t
367  "Non-nil means save word abbrevs too when files are saved.
368If `silently', don't ask the user before saving."
369  :type '(choice (const t) (const nil) (const silently))
370  :group 'abbrev)
371
372(defcustom find-file-run-dired t
373  "Non-nil means allow `find-file' to visit directories.
374To visit the directory, `find-file' runs `find-directory-functions'."
375  :type 'boolean
376  :group 'find-file)
377
378(defcustom find-directory-functions '(cvs-dired-noselect dired-noselect)
379  "List of functions to try in sequence to visit a directory.
380Each function is called with the directory name as the sole argument
381and should return either a buffer or nil."
382  :type '(hook :options (cvs-dired-noselect dired-noselect))
383  :group 'find-file)
384
385;;;It is not useful to make this a local variable.
386;;;(put 'find-file-not-found-hooks 'permanent-local t)
387(defvar find-file-not-found-functions nil
388  "List of functions to be called for `find-file' on nonexistent file.
389These functions are called as soon as the error is detected.
390Variable `buffer-file-name' is already set up.
391The functions are called in the order given until one of them returns non-nil.")
392(define-obsolete-variable-alias 'find-file-not-found-hooks
393    'find-file-not-found-functions "22.1")
394
395;;;It is not useful to make this a local variable.
396;;;(put 'find-file-hooks 'permanent-local t)
397(defcustom find-file-hook nil
398  "List of functions to be called after a buffer is loaded from a file.
399The buffer's local variables (if any) will have been processed before the
400functions are called."
401  :group 'find-file
402  :type 'hook
403  :options '(auto-insert)
404  :version "22.1")
405(define-obsolete-variable-alias 'find-file-hooks 'find-file-hook "22.1")
406
407(defvar write-file-functions nil
408  "List of functions to be called before writing out a buffer to a file.
409If one of them returns non-nil, the file is considered already written
410and the rest are not called.
411These hooks are considered to pertain to the visited file.
412So any buffer-local binding of this variable is discarded if you change
413the visited file name with \\[set-visited-file-name], but not when you
414change the major mode.
415
416This hook is not run if any of the functions in
417`write-contents-functions' returns non-nil.  Both hooks pertain
418to how to save a buffer to file, for instance, choosing a suitable
419coding system and setting mode bits.  (See Info
420node `(elisp)Saving Buffers'.)  To perform various checks or
421updates before the buffer is saved, use `before-save-hook'.")
422(put 'write-file-functions 'permanent-local t)
423(define-obsolete-variable-alias 'write-file-hooks 'write-file-functions "22.1")
424
425(defvar local-write-file-hooks nil)
426(make-variable-buffer-local 'local-write-file-hooks)
427(put 'local-write-file-hooks 'permanent-local t)
428(make-obsolete-variable 'local-write-file-hooks 'write-file-functions "22.1")
429
430(defvar write-contents-functions nil
431  "List of functions to be called before writing out a buffer to a file.
432If one of them returns non-nil, the file is considered already written
433and the rest are not called and neither are the functions in
434`write-file-functions'.
435
436This variable is meant to be used for hooks that pertain to the
437buffer's contents, not to the particular visited file; thus,
438`set-visited-file-name' does not clear this variable; but changing the
439major mode does clear it.
440
441For hooks that _do_ pertain to the particular visited file, use
442`write-file-functions'.  Both this variable and
443`write-file-functions' relate to how a buffer is saved to file.
444To perform various checks or updates before the buffer is saved,
445use `before-save-hook'.")
446(make-variable-buffer-local 'write-contents-functions)
447(define-obsolete-variable-alias 'write-contents-hooks
448    'write-contents-functions "22.1")
449
450(defcustom enable-local-variables t
451  "Control use of local variables in files you visit.
452The value can be t, nil, :safe, or something else.
453
454A value of t means file local variables specifications are obeyed
455if all the specified variable values are safe; if any values are
456not safe, Emacs queries you, once, whether to set them all.
457\(When you say yes to certain values, they are remembered as safe.)
458
459:safe means set the safe variables, and ignore the rest.
460:all means set all variables, whether safe or not.
461 (Don't set it permanently to :all.)
462A value of nil means always ignore the file local variables.
463
464Any other value means always query you once whether to set them all.
465\(When you say yes to certain values, they are remembered as safe, but
466this has no effect when `enable-local-variables' is \"something else\".)
467
468This variable also controls use of major modes specified in
469a -*- line.
470
471The command \\[normal-mode], when used interactively,
472always obeys file local variable specifications and the -*- line,
473and ignores this variable."
474  :type '(choice (const :tag "Query Unsafe" t)
475		 (const :tag "Safe Only" :safe)
476		 (const :tag "Do all" :all)
477		 (const :tag "Ignore" nil)
478		 (other :tag "Query" other))
479  :group 'find-file)
480
481(defvar local-enable-local-variables t
482  "Like `enable-local-variables' but meant for buffer-local bindings.
483The meaningful values are nil and non-nil.  The default is non-nil.
484If a major mode sets this to nil, buffer-locally, then any local
485variables list in the file will be ignored.
486
487This variable does not affect the use of major modes
488specified in a -*- line.")
489
490(defcustom enable-local-eval 'maybe
491  "Control processing of the \"variable\" `eval' in a file's local variables.
492The value can be t, nil or something else.
493A value of t means obey `eval' variables;
494A value of nil means ignore them; anything else means query."
495  :type '(choice (const :tag "Obey" t)
496		 (const :tag "Ignore" nil)
497		 (other :tag "Query" other))
498  :group 'find-file)
499
500;; Avoid losing in versions where CLASH_DETECTION is disabled.
501(or (fboundp 'lock-buffer)
502    (defalias 'lock-buffer 'ignore))
503(or (fboundp 'unlock-buffer)
504    (defalias 'unlock-buffer 'ignore))
505(or (fboundp 'file-locked-p)
506    (defalias 'file-locked-p 'ignore))
507
508(defcustom view-read-only nil
509  "Non-nil means buffers visiting files read-only do so in view mode.
510In fact, this means that all read-only buffers normally have
511View mode enabled, including buffers that are read-only because
512you visit a file you cannot alter, and buffers you make read-only
513using \\[toggle-read-only]."
514  :type 'boolean
515  :group 'view)
516
517(defvar file-name-history nil
518  "History list of file names entered in the minibuffer.")
519
520(put 'ange-ftp-completion-hook-function 'safe-magic t)
521(defun ange-ftp-completion-hook-function (op &rest args)
522  "Provides support for ange-ftp host name completion.
523Runs the usual ange-ftp hook, but only for completion operations."
524  ;; Having this here avoids the need to load ange-ftp when it's not
525  ;; really in use.
526  (if (memq op '(file-name-completion file-name-all-completions))
527      (apply 'ange-ftp-hook-function op args)
528    (let ((inhibit-file-name-handlers
529	   (cons 'ange-ftp-completion-hook-function
530		 (and (eq inhibit-file-name-operation op)
531		      inhibit-file-name-handlers)))
532	  (inhibit-file-name-operation op))
533      (apply op args))))
534
535(defun convert-standard-filename (filename)
536  "Convert a standard file's name to something suitable for the OS.
537This means to guarantee valid names and perhaps to canonicalize
538certain patterns.
539
540FILENAME should be an absolute file name since the conversion rules
541sometimes vary depending on the position in the file name.  E.g. c:/foo
542is a valid DOS file name, but c:/bar/c:/foo is not.
543
544This function's standard definition is trivial; it just returns
545the argument.  However, on Windows and DOS, replace invalid
546characters.  On DOS, make sure to obey the 8.3 limitations.
547In the native Windows build, turn Cygwin names into native names,
548and also turn slashes into backslashes if the shell requires it (see
549`w32-shell-dos-semantics').
550
551See Info node `(elisp)Standard File Names' for more details."
552  (if (eq system-type 'cygwin)
553      (let ((name (copy-sequence filename))
554	    (start 0))
555	;; Replace invalid filename characters with !
556	(while (string-match "[?*:<>|\"\000-\037]" name start)
557	  (aset name (match-beginning 0) ?!)
558	  (setq start (match-end 0)))
559	name)
560    filename))
561
562(defun read-directory-name (prompt &optional dir default-dirname mustmatch initial)
563  "Read directory name, prompting with PROMPT and completing in directory DIR.
564Value is not expanded---you must call `expand-file-name' yourself.
565Default name to DEFAULT-DIRNAME if user exits with the same
566non-empty string that was inserted by this function.
567 (If DEFAULT-DIRNAME is omitted, DIR combined with INITIAL is used,
568  or just DIR if INITIAL is nil.)
569If the user exits with an empty minibuffer, this function returns
570an empty string.  (This can only happen if the user erased the
571pre-inserted contents or if `insert-default-directory' is nil.)
572Fourth arg MUSTMATCH non-nil means require existing directory's name.
573 Non-nil and non-t means also require confirmation after completion.
574Fifth arg INITIAL specifies text to start with.
575DIR should be an absolute directory name.  It defaults to
576the value of `default-directory'."
577  (unless dir
578    (setq dir default-directory))
579  (read-file-name prompt dir (or default-dirname
580				 (if initial (expand-file-name initial dir)
581				   dir))
582		  mustmatch initial
583		  'file-directory-p))
584
585
586(defun pwd ()
587  "Show the current default directory."
588  (interactive nil)
589  (message "Directory %s" default-directory))
590
591(defvar cd-path nil
592  "Value of the CDPATH environment variable, as a list.
593Not actually set up until the first time you use it.")
594
595(defun parse-colon-path (cd-path)
596  "Explode a search path into a list of directory names.
597Directories are separated by occurrences of `path-separator'
598\(which is colon in GNU and GNU-like systems)."
599  ;; We could use split-string here.
600  (and cd-path
601       (let (cd-list (cd-start 0) cd-colon)
602	 (setq cd-path (concat cd-path path-separator))
603	 (while (setq cd-colon (string-match path-separator cd-path cd-start))
604	   (setq cd-list
605		 (nconc cd-list
606			(list (if (= cd-start cd-colon)
607				   nil
608				(substitute-in-file-name
609				 (file-name-as-directory
610				  (substring cd-path cd-start cd-colon)))))))
611	   (setq cd-start (+ cd-colon 1)))
612	 cd-list)))
613
614(defun cd-absolute (dir)
615  "Change current directory to given absolute file name DIR."
616  ;; Put the name into directory syntax now,
617  ;; because otherwise expand-file-name may give some bad results.
618  (if (not (eq system-type 'vax-vms))
619      (setq dir (file-name-as-directory dir)))
620  (setq dir (abbreviate-file-name (expand-file-name dir)))
621  (if (not (file-directory-p dir))
622      (if (file-exists-p dir)
623	  (error "%s is not a directory" dir)
624	(error "%s: no such directory" dir))
625    (if (file-executable-p dir)
626	(setq default-directory dir)
627      (error "Cannot cd to %s:  Permission denied" dir))))
628
629(defun cd (dir)
630  "Make DIR become the current buffer's default directory.
631If your environment includes a `CDPATH' variable, try each one of
632that list of directories (separated by occurrences of
633`path-separator') when resolving a relative directory name.
634The path separator is colon in GNU and GNU-like systems."
635  (interactive
636   (list (read-directory-name "Change default directory: "
637			 default-directory default-directory
638			 (and (member cd-path '(nil ("./")))
639			      (null (getenv "CDPATH"))))))
640  (if (file-name-absolute-p dir)
641      (cd-absolute (expand-file-name dir))
642    (if (null cd-path)
643	(let ((trypath (parse-colon-path (getenv "CDPATH"))))
644	  (setq cd-path (or trypath (list "./")))))
645    (if (not (catch 'found
646	       (mapcar
647		(function (lambda (x)
648			    (let ((f (expand-file-name (concat x dir))))
649			      (if (file-directory-p f)
650				  (progn
651				    (cd-absolute f)
652				    (throw 'found t))))))
653		cd-path)
654	       nil))
655	(error "No such directory found via CDPATH environment variable"))))
656
657(defun load-file (file)
658  "Load the Lisp file named FILE."
659  ;; This is a case where .elc makes a lot of sense.
660  (interactive (list (let ((completion-ignored-extensions
661			    (remove ".elc" completion-ignored-extensions)))
662		       (read-file-name "Load file: "))))
663  (load (expand-file-name file) nil nil t))
664
665(defun locate-file (filename path &optional suffixes predicate)
666  "Search for FILENAME through PATH.
667If found, return the absolute file name of FILENAME, with its suffixes;
668otherwise return nil.
669PATH should be a list of directories to look in, like the lists in
670`exec-path' or `load-path'.
671If SUFFIXES is non-nil, it should be a list of suffixes to append to
672file name when searching.  If SUFFIXES is nil, it is equivalent to '(\"\").
673Use '(\"/\") to disable PATH search, but still try the suffixes in SUFFIXES.
674If non-nil, PREDICATE is used instead of `file-readable-p'.
675PREDICATE can also be an integer to pass to the `access' system call,
676in which case file-name handlers are ignored.  This usage is deprecated.
677
678For compatibility, PREDICATE can also be one of the symbols
679`executable', `readable', `writable', or `exists', or a list of
680one or more of those symbols."
681  (if (and predicate (symbolp predicate) (not (functionp predicate)))
682      (setq predicate (list predicate)))
683  (when (and (consp predicate) (not (functionp predicate)))
684    (setq predicate
685	  (logior (if (memq 'executable predicate) 1 0)
686		  (if (memq 'writable predicate) 2 0)
687		  (if (memq 'readable predicate) 4 0))))
688  (locate-file-internal filename path suffixes predicate))
689
690(defun locate-file-completion (string path-and-suffixes action)
691  "Do completion for file names passed to `locate-file'.
692PATH-AND-SUFFIXES is a pair of lists, (DIRECTORIES . SUFFIXES)."
693  (if (file-name-absolute-p string)
694      (read-file-name-internal string nil action)
695    (let ((names nil)
696	  (suffix (concat (regexp-opt (cdr path-and-suffixes) t) "\\'"))
697	  (string-dir (file-name-directory string)))
698      (dolist (dir (car path-and-suffixes))
699	(unless dir
700	  (setq dir default-directory))
701	(if string-dir (setq dir (expand-file-name string-dir dir)))
702	(when (file-directory-p dir)
703	  (dolist (file (file-name-all-completions
704			 (file-name-nondirectory string) dir))
705	    (add-to-list 'names (if string-dir (concat string-dir file) file))
706	    (when (string-match suffix file)
707	      (setq file (substring file 0 (match-beginning 0)))
708	      (push (if string-dir (concat string-dir file) file) names)))))
709      (cond
710       ((eq action t) (all-completions string names))
711       ((null action) (try-completion string names))
712       (t (test-completion string names))))))
713
714(defun executable-find (command)
715  "Search for COMMAND in `exec-path' and return the absolute file name.
716Return nil if COMMAND is not found anywhere in `exec-path'."
717  ;; Use 1 rather than file-executable-p to better match the behavior of
718  ;; call-process.
719  (locate-file command exec-path exec-suffixes 1))
720
721(defun load-library (library)
722  "Load the library named LIBRARY.
723This is an interface to the function `load'."
724  (interactive
725   (list (completing-read "Load library: "
726			  'locate-file-completion
727			  (cons load-path (get-load-suffixes)))))
728  (load library))
729
730(defun file-remote-p (file)
731  "Test whether FILE specifies a location on a remote system.
732Return an identification of the system if the location is indeed
733remote.  The identification of the system may comprise a method
734to access the system and its hostname, amongst other things.
735
736For example, the filename \"/user@host:/foo\" specifies a location
737on the system \"/user@host:\"."
738  (let ((handler (find-file-name-handler file 'file-remote-p)))
739    (if handler
740	(funcall handler 'file-remote-p file)
741      nil)))
742
743(defun file-local-copy (file)
744  "Copy the file FILE into a temporary file on this machine.
745Returns the name of the local copy, or nil, if FILE is directly
746accessible."
747  ;; This formerly had an optional BUFFER argument that wasn't used by
748  ;; anything.
749  (let ((handler (find-file-name-handler file 'file-local-copy)))
750    (if handler
751	(funcall handler 'file-local-copy file)
752      nil)))
753
754(defun file-truename (filename &optional counter prev-dirs)
755  "Return the truename of FILENAME, which should be absolute.
756The truename of a file name is found by chasing symbolic links
757both at the level of the file and at the level of the directories
758containing it, until no links are left at any level.
759
760\(fn FILENAME)"  ;; Don't document the optional arguments.
761  ;; COUNTER and PREV-DIRS are only used in recursive calls.
762  ;; COUNTER can be a cons cell whose car is the count of how many
763  ;; more links to chase before getting an error.
764  ;; PREV-DIRS can be a cons cell whose car is an alist
765  ;; of truenames we've just recently computed.
766  (cond ((or (string= filename "") (string= filename "~"))
767	 (setq filename (expand-file-name filename))
768	 (if (string= filename "")
769	     (setq filename "/")))
770	((and (string= (substring filename 0 1) "~")
771	      (string-match "~[^/]*/?" filename))
772	 (let ((first-part
773		(substring filename 0 (match-end 0)))
774	       (rest (substring filename (match-end 0))))
775	   (setq filename (concat (expand-file-name first-part) rest)))))
776
777  (or counter (setq counter (list 100)))
778  (let (done
779	;; For speed, remove the ange-ftp completion handler from the list.
780	;; We know it's not needed here.
781	;; For even more speed, do this only on the outermost call.
782	(file-name-handler-alist
783	 (if prev-dirs file-name-handler-alist
784	   (let ((tem (copy-sequence file-name-handler-alist)))
785	     (delq (rassq 'ange-ftp-completion-hook-function tem) tem)))))
786    (or prev-dirs (setq prev-dirs (list nil)))
787
788    ;; andrewi@harlequin.co.uk - none of the following code (except for
789    ;; invoking the file-name handler) currently applies on Windows
790    ;; (ie. there are no native symlinks), but there is an issue with
791    ;; case differences being ignored by the OS, and short "8.3 DOS"
792    ;; name aliases existing for all files.  (The short names are not
793    ;; reported by directory-files, but can be used to refer to files.)
794    ;; It seems appropriate for file-truename to resolve these issues in
795    ;; the most natural way, which on Windows is to call the function
796    ;; `w32-long-file-name' - this returns the exact name of a file as
797    ;; it is stored on disk (expanding short name aliases with the full
798    ;; name in the process).
799    (if (eq system-type 'windows-nt)
800      (let ((handler (find-file-name-handler filename 'file-truename)))
801	;; For file name that has a special handler, call handler.
802	;; This is so that ange-ftp can save time by doing a no-op.
803	(if handler
804	    (setq filename (funcall handler 'file-truename filename))
805	  ;; If filename contains a wildcard, newname will be the old name.
806	  (unless (string-match "[[*?]" filename)
807	    ;; If filename exists, use the long name
808	    (setq filename (or (w32-long-file-name filename) filename))))
809	(setq done t)))
810
811    ;; If this file directly leads to a link, process that iteratively
812    ;; so that we don't use lots of stack.
813    (while (not done)
814      (setcar counter (1- (car counter)))
815      (if (< (car counter) 0)
816	  (error "Apparent cycle of symbolic links for %s" filename))
817      (let ((handler (find-file-name-handler filename 'file-truename)))
818	;; For file name that has a special handler, call handler.
819	;; This is so that ange-ftp can save time by doing a no-op.
820	(if handler
821	    (setq filename (funcall handler 'file-truename filename)
822		  done t)
823	  (let ((dir (or (file-name-directory filename) default-directory))
824		target dirfile)
825	    ;; Get the truename of the directory.
826	    (setq dirfile (directory-file-name dir))
827	    ;; If these are equal, we have the (or a) root directory.
828	    (or (string= dir dirfile)
829		;; If this is the same dir we last got the truename for,
830		;; save time--don't recalculate.
831		(if (assoc dir (car prev-dirs))
832		    (setq dir (cdr (assoc dir (car prev-dirs))))
833		  (let ((old dir)
834			(new (file-name-as-directory (file-truename dirfile counter prev-dirs))))
835		    (setcar prev-dirs (cons (cons old new) (car prev-dirs)))
836		    (setq dir new))))
837	    (if (equal ".." (file-name-nondirectory filename))
838		(setq filename
839		      (directory-file-name (file-name-directory (directory-file-name dir)))
840		      done t)
841	      (if (equal "." (file-name-nondirectory filename))
842		  (setq filename (directory-file-name dir)
843			done t)
844		;; Put it back on the file name.
845		(setq filename (concat dir (file-name-nondirectory filename)))
846		;; Is the file name the name of a link?
847		(setq target (file-symlink-p filename))
848		(if target
849		    ;; Yes => chase that link, then start all over
850		    ;; since the link may point to a directory name that uses links.
851		    ;; We can't safely use expand-file-name here
852		    ;; since target might look like foo/../bar where foo
853		    ;; is itself a link.  Instead, we handle . and .. above.
854		    (setq filename
855			  (if (file-name-absolute-p target)
856			      target
857			    (concat dir target))
858			  done nil)
859		  ;; No, we are done!
860		  (setq done t))))))))
861    filename))
862
863(defun file-chase-links (filename &optional limit)
864  "Chase links in FILENAME until a name that is not a link.
865Unlike `file-truename', this does not check whether a parent
866directory name is a symbolic link.
867If the optional argument LIMIT is a number,
868it means chase no more than that many links and then stop."
869  (let (tem (newname filename)
870	    (count 0))
871    (while (and (or (null limit) (< count limit))
872		(setq tem (file-symlink-p newname)))
873      (save-match-data
874	(if (and (null limit) (= count 100))
875	    (error "Apparent cycle of symbolic links for %s" filename))
876	;; In the context of a link, `//' doesn't mean what Emacs thinks.
877	(while (string-match "//+" tem)
878	  (setq tem (replace-match "/" nil nil tem)))
879	;; Handle `..' by hand, since it needs to work in the
880	;; target of any directory symlink.
881	;; This code is not quite complete; it does not handle
882	;; embedded .. in some cases such as ./../foo and foo/bar/../../../lose.
883	(while (string-match "\\`\\.\\./" tem)
884	  (setq tem (substring tem 3))
885	  (setq newname (expand-file-name newname))
886	  ;; Chase links in the default dir of the symlink.
887	  (setq newname
888		(file-chase-links
889		 (directory-file-name (file-name-directory newname))))
890	  ;; Now find the parent of that dir.
891	  (setq newname (file-name-directory newname)))
892	(setq newname (expand-file-name tem (file-name-directory newname)))
893	(setq count (1+ count))))
894    newname))
895
896(defun make-temp-file (prefix &optional dir-flag suffix)
897  "Create a temporary file.
898The returned file name (created by appending some random characters at the end
899of PREFIX, and expanding against `temporary-file-directory' if necessary),
900is guaranteed to point to a newly created empty file.
901You can then use `write-region' to write new data into the file.
902
903If DIR-FLAG is non-nil, create a new empty directory instead of a file.
904
905If SUFFIX is non-nil, add that at the end of the file name."
906  (let ((umask (default-file-modes))
907	file)
908    (unwind-protect
909	(progn
910	  ;; Create temp files with strict access rights.  It's easy to
911	  ;; loosen them later, whereas it's impossible to close the
912	  ;; time-window of loose permissions otherwise.
913	  (set-default-file-modes ?\700)
914	  (while (condition-case ()
915		     (progn
916		       (setq file
917			     (make-temp-name
918			      (expand-file-name prefix temporary-file-directory)))
919		       (if suffix
920			   (setq file (concat file suffix)))
921		       (if dir-flag
922			   (make-directory file)
923			 (write-region "" nil file nil 'silent nil 'excl))
924		       nil)
925		   (file-already-exists t))
926	    ;; the file was somehow created by someone else between
927	    ;; `make-temp-name' and `write-region', let's try again.
928	    nil)
929	  file)
930      ;; Reset the umask.
931      (set-default-file-modes umask))))
932
933(defun recode-file-name (file coding new-coding &optional ok-if-already-exists)
934  "Change the encoding of FILE's name from CODING to NEW-CODING.
935The value is a new name of FILE.
936Signals a `file-already-exists' error if a file of the new name
937already exists unless optional fourth argument OK-IF-ALREADY-EXISTS
938is non-nil.  A number as fourth arg means request confirmation if
939the new name already exists.  This is what happens in interactive
940use with M-x."
941  (interactive
942   (let ((default-coding (or file-name-coding-system
943			     default-file-name-coding-system))
944	 (filename (read-file-name "Recode filename: " nil nil t))
945	 from-coding to-coding)
946     (if (and default-coding
947	      ;; We provide the default coding only when it seems that
948	      ;; the filename is correctly decoded by the default
949	      ;; coding.
950	      (let ((charsets (find-charset-string filename)))
951		(and (not (memq 'eight-bit-control charsets))
952		     (not (memq 'eight-bit-graphic charsets)))))
953	 (setq from-coding (read-coding-system
954			    (format "Recode filename %s from (default %s): "
955				    filename default-coding)
956			    default-coding))
957       (setq from-coding (read-coding-system
958			  (format "Recode filename %s from: " filename))))
959
960     ;; We provide the default coding only when a user is going to
961     ;; change the encoding not from the default coding.
962     (if (eq from-coding default-coding)
963	 (setq to-coding (read-coding-system
964			  (format "Recode filename %s from %s to: "
965				  filename from-coding)))
966       (setq to-coding (read-coding-system
967			(format "Recode filename %s from %s to (default %s): "
968				filename from-coding default-coding)
969			default-coding)))
970     (list filename from-coding to-coding)))
971
972  (let* ((default-coding (or file-name-coding-system
973			     default-file-name-coding-system))
974	 ;; FILE should have been decoded by DEFAULT-CODING.
975	 (encoded (encode-coding-string file default-coding))
976	 (newname (decode-coding-string encoded coding))
977	 (new-encoded (encode-coding-string newname new-coding))
978	 ;; Suppress further encoding.
979	 (file-name-coding-system nil)
980	 (default-file-name-coding-system nil)
981	 (locale-coding-system nil))
982    (rename-file encoded new-encoded ok-if-already-exists)
983    newname))
984
985(defun switch-to-buffer-other-window (buffer &optional norecord)
986  "Select buffer BUFFER in another window.
987If BUFFER does not identify an existing buffer, then this function
988creates a buffer with that name.
989
990When called from Lisp, BUFFER can be a buffer, a string \(a buffer name),
991or nil.  If BUFFER is nil, then this function chooses a buffer
992using `other-buffer'.
993Optional second arg NORECORD non-nil means
994do not put this buffer at the front of the list of recently selected ones.
995This function returns the buffer it switched to.
996
997This uses the function `display-buffer' as a subroutine; see its
998documentation for additional customization information."
999  (interactive "BSwitch to buffer in other window: ")
1000  (let ((pop-up-windows t)
1001	;; Don't let these interfere.
1002	same-window-buffer-names same-window-regexps)
1003    (pop-to-buffer buffer t norecord)))
1004
1005(defun switch-to-buffer-other-frame (buffer &optional norecord)
1006  "Switch to buffer BUFFER in another frame.
1007Optional second arg NORECORD non-nil means
1008do not put this buffer at the front of the list of recently selected ones.
1009
1010This uses the function `display-buffer' as a subroutine; see its
1011documentation for additional customization information."
1012  (interactive "BSwitch to buffer in other frame: ")
1013  (let ((pop-up-frames t)
1014	same-window-buffer-names same-window-regexps)
1015    (pop-to-buffer buffer t norecord)
1016    (raise-frame (window-frame (selected-window)))))
1017
1018(defun display-buffer-other-frame (buffer)
1019  "Switch to buffer BUFFER in another frame.
1020This uses the function `display-buffer' as a subroutine; see its
1021documentation for additional customization information."
1022  (interactive "BDisplay buffer in other frame: ")
1023  (let ((pop-up-frames t)
1024	same-window-buffer-names same-window-regexps
1025        (old-window (selected-window))
1026	new-window)
1027    (setq new-window (display-buffer buffer t))
1028    (lower-frame (window-frame new-window))
1029    (make-frame-invisible (window-frame old-window))
1030    (make-frame-visible (window-frame old-window))))
1031
1032(defvar find-file-default nil
1033  "Used within `find-file-read-args'.")
1034
1035(defmacro minibuffer-with-setup-hook (fun &rest body)
1036  "Add FUN to `minibuffer-setup-hook' while executing BODY.
1037BODY should use the minibuffer at most once.
1038Recursive uses of the minibuffer will not be affected."
1039  (declare (indent 1) (debug t))
1040  (let ((hook (make-symbol "setup-hook")))
1041    `(let (,hook)
1042       (setq ,hook
1043	     (lambda ()
1044	       ;; Clear out this hook so it does not interfere
1045	       ;; with any recursive minibuffer usage.
1046	       (remove-hook 'minibuffer-setup-hook ,hook)
1047	       (,fun)))
1048       (unwind-protect
1049	   (progn
1050	     (add-hook 'minibuffer-setup-hook ,hook)
1051	     ,@body)
1052	 (remove-hook 'minibuffer-setup-hook ,hook)))))
1053
1054(defun find-file-read-args (prompt mustmatch)
1055  (list (let ((find-file-default
1056	       (and buffer-file-name
1057		    (abbreviate-file-name buffer-file-name))))
1058	  (minibuffer-with-setup-hook
1059	      (lambda () (setq minibuffer-default find-file-default))
1060	    (read-file-name prompt nil default-directory mustmatch)))
1061	t))
1062
1063(defun find-file (filename &optional wildcards)
1064  "Edit file FILENAME.
1065Switch to a buffer visiting file FILENAME,
1066creating one if none already exists.
1067Interactively, the default if you just type RET is the current directory,
1068but the visited file name is available through the minibuffer history:
1069type M-n to pull it into the minibuffer.
1070
1071Interactively, or if WILDCARDS is non-nil in a call from Lisp,
1072expand wildcards (if any) and visit multiple files.  You can
1073suppress wildcard expansion by setting `find-file-wildcards' to nil.
1074
1075To visit a file without any kind of conversion and without
1076automatically choosing a major mode, use \\[find-file-literally]."
1077  (interactive (find-file-read-args "Find file: " nil))
1078  (let ((value (find-file-noselect filename nil nil wildcards)))
1079    (if (listp value)
1080	(mapcar 'switch-to-buffer (nreverse value))
1081      (switch-to-buffer value))))
1082
1083(defun find-file-other-window (filename &optional wildcards)
1084  "Edit file FILENAME, in another window.
1085May create a new window, or reuse an existing one.
1086See the function `display-buffer'.
1087
1088Interactively, the default if you just type RET is the current directory,
1089but the visited file name is available through the minibuffer history:
1090type M-n to pull it into the minibuffer.
1091
1092Interactively, or if WILDCARDS is non-nil in a call from Lisp,
1093expand wildcards (if any) and visit multiple files."
1094  (interactive (find-file-read-args "Find file in other window: " nil))
1095  (let ((value (find-file-noselect filename nil nil wildcards)))
1096    (if (listp value)
1097	(progn
1098	  (setq value (nreverse value))
1099	  (cons (switch-to-buffer-other-window (car value))
1100		(mapcar 'switch-to-buffer (cdr value))))
1101      (switch-to-buffer-other-window value))))
1102
1103(defun find-file-other-frame (filename &optional wildcards)
1104  "Edit file FILENAME, in another frame.
1105May create a new frame, or reuse an existing one.
1106See the function `display-buffer'.
1107
1108Interactively, the default if you just type RET is the current directory,
1109but the visited file name is available through the minibuffer history:
1110type M-n to pull it into the minibuffer.
1111
1112Interactively, or if WILDCARDS is non-nil in a call from Lisp,
1113expand wildcards (if any) and visit multiple files."
1114  (interactive (find-file-read-args "Find file in other frame: " nil))
1115  (let ((value (find-file-noselect filename nil nil wildcards)))
1116    (if (listp value)
1117	(progn
1118	  (setq value (nreverse value))
1119	  (cons (switch-to-buffer-other-frame (car value))
1120		(mapcar 'switch-to-buffer (cdr value))))
1121      (switch-to-buffer-other-frame value))))
1122
1123(defun find-file-existing (filename)
1124   "Edit the existing file FILENAME.
1125Like \\[find-file] but only allow a file that exists, and do not allow
1126file names with wildcards."
1127   (interactive (nbutlast (find-file-read-args "Find existing file: " t)))
1128   (if (and (not (interactive-p)) (not (file-exists-p filename)))
1129       (error "%s does not exist" filename)
1130     (find-file filename)
1131     (current-buffer)))
1132
1133(defun find-file-read-only (filename &optional wildcards)
1134  "Edit file FILENAME but don't allow changes.
1135Like \\[find-file] but marks buffer as read-only.
1136Use \\[toggle-read-only] to permit editing."
1137  (interactive (find-file-read-args "Find file read-only: " nil))
1138  (unless (or (and wildcards find-file-wildcards
1139		   (not (string-match "\\`/:" filename))
1140		   (string-match "[[*?]" filename))
1141	      (file-exists-p filename))
1142    (error "%s does not exist" filename))
1143  (let ((value (find-file filename wildcards)))
1144    (mapc (lambda (b) (with-current-buffer b (toggle-read-only 1)))
1145	  (if (listp value) value (list value)))
1146    value))
1147
1148(defun find-file-read-only-other-window (filename &optional wildcards)
1149  "Edit file FILENAME in another window but don't allow changes.
1150Like \\[find-file-other-window] but marks buffer as read-only.
1151Use \\[toggle-read-only] to permit editing."
1152  (interactive (find-file-read-args "Find file read-only other window: " nil))
1153  (unless (or (and wildcards find-file-wildcards
1154		   (not (string-match "\\`/:" filename))
1155		   (string-match "[[*?]" filename))
1156	      (file-exists-p filename))
1157    (error "%s does not exist" filename))
1158  (let ((value (find-file-other-window filename wildcards)))
1159    (mapc (lambda (b) (with-current-buffer b (toggle-read-only 1)))
1160	  (if (listp value) value (list value)))
1161    value))
1162
1163(defun find-file-read-only-other-frame (filename &optional wildcards)
1164  "Edit file FILENAME in another frame but don't allow changes.
1165Like \\[find-file-other-frame] but marks buffer as read-only.
1166Use \\[toggle-read-only] to permit editing."
1167  (interactive (find-file-read-args "Find file read-only other frame: " nil))
1168  (unless (or (and wildcards find-file-wildcards
1169		   (not (string-match "\\`/:" filename))
1170		   (string-match "[[*?]" filename))
1171	      (file-exists-p filename))
1172    (error "%s does not exist" filename))
1173  (let ((value (find-file-other-frame filename wildcards)))
1174    (mapc (lambda (b) (with-current-buffer b (toggle-read-only 1)))
1175	  (if (listp value) value (list value)))
1176    value))
1177
1178(defun find-alternate-file-other-window (filename &optional wildcards)
1179  "Find file FILENAME as a replacement for the file in the next window.
1180This command does not select that window.
1181
1182Interactively, or if WILDCARDS is non-nil in a call from Lisp,
1183expand wildcards (if any) and replace the file with multiple files."
1184  (interactive
1185   (save-selected-window
1186     (other-window 1)
1187     (let ((file buffer-file-name)
1188	   (file-name nil)
1189	   (file-dir nil))
1190       (and file
1191	    (setq file-name (file-name-nondirectory file)
1192		  file-dir (file-name-directory file)))
1193       (list (read-file-name
1194	      "Find alternate file: " file-dir nil nil file-name)
1195	     t))))
1196  (if (one-window-p)
1197      (find-file-other-window filename wildcards)
1198    (save-selected-window
1199      (other-window 1)
1200      (find-alternate-file filename wildcards))))
1201
1202(defun find-alternate-file (filename &optional wildcards)
1203  "Find file FILENAME, select its buffer, kill previous buffer.
1204If the current buffer now contains an empty file that you just visited
1205\(presumably by mistake), use this command to visit the file you really want.
1206
1207Interactively, or if WILDCARDS is non-nil in a call from Lisp,
1208expand wildcards (if any) and replace the file with multiple files.
1209
1210If the current buffer is an indirect buffer, or the base buffer
1211for one or more indirect buffers, the other buffer(s) are not
1212killed."
1213  (interactive
1214   (let ((file buffer-file-name)
1215	 (file-name nil)
1216	 (file-dir nil))
1217     (and file
1218	  (setq file-name (file-name-nondirectory file)
1219		file-dir (file-name-directory file)))
1220     (list (read-file-name
1221	    "Find alternate file: " file-dir nil nil file-name)
1222	   t)))
1223  (unless (run-hook-with-args-until-failure 'kill-buffer-query-functions)
1224    (error "Aborted"))
1225  (when (and (buffer-modified-p) (buffer-file-name))
1226    (if (yes-or-no-p (format "Buffer %s is modified; kill anyway? "
1227			     (buffer-name)))
1228	(unless (yes-or-no-p "Kill and replace the buffer without saving it? ")
1229	  (error "Aborted"))
1230      (save-buffer)))
1231  (let ((obuf (current-buffer))
1232	(ofile buffer-file-name)
1233	(onum buffer-file-number)
1234	(odir dired-directory)
1235	(otrue buffer-file-truename)
1236	(oname (buffer-name)))
1237    (if (get-buffer " **lose**")
1238	(kill-buffer " **lose**"))
1239    (rename-buffer " **lose**")
1240    (unwind-protect
1241	(progn
1242	  (unlock-buffer)
1243	  ;; This prevents us from finding the same buffer
1244	  ;; if we specified the same file again.
1245	  (setq buffer-file-name nil)
1246	  (setq buffer-file-number nil)
1247	  (setq buffer-file-truename nil)
1248	  ;; Likewise for dired buffers.
1249	  (setq dired-directory nil)
1250	  (find-file filename wildcards))
1251      (when (eq obuf (current-buffer))
1252	;; This executes if find-file gets an error
1253	;; and does not really find anything.
1254	;; We put things back as they were.
1255	;; If find-file actually finds something, we kill obuf below.
1256	(setq buffer-file-name ofile)
1257	(setq buffer-file-number onum)
1258	(setq buffer-file-truename otrue)
1259	(setq dired-directory odir)
1260	(lock-buffer)
1261	(rename-buffer oname)))
1262    (unless (eq (current-buffer) obuf)
1263      (with-current-buffer obuf
1264	;; We already asked; don't ask again.
1265	(let ((kill-buffer-query-functions))
1266	  (kill-buffer obuf))))))
1267
1268(defun create-file-buffer (filename)
1269  "Create a suitably named buffer for visiting FILENAME, and return it.
1270FILENAME (sans directory) is used unchanged if that name is free;
1271otherwise a string <2> or <3> or ... is appended to get an unused name."
1272  (let ((lastname (file-name-nondirectory filename)))
1273    (if (string= lastname "")
1274	(setq lastname filename))
1275    (generate-new-buffer lastname)))
1276
1277(defun generate-new-buffer (name)
1278  "Create and return a buffer with a name based on NAME.
1279Choose the buffer's name using `generate-new-buffer-name'."
1280  (get-buffer-create (generate-new-buffer-name name)))
1281
1282(defcustom automount-dir-prefix "^/tmp_mnt/"
1283  "Regexp to match the automounter prefix in a directory name."
1284  :group 'files
1285  :type 'regexp)
1286
1287(defvar abbreviated-home-dir nil
1288  "The user's homedir abbreviated according to `directory-abbrev-alist'.")
1289
1290(defun abbreviate-file-name (filename)
1291  "Return a version of FILENAME shortened using `directory-abbrev-alist'.
1292This also substitutes \"~\" for the user's home directory (unless the
1293home directory is a root directory) and removes automounter prefixes
1294\(see the variable `automount-dir-prefix')."
1295  ;; Get rid of the prefixes added by the automounter.
1296  (save-match-data
1297    (if (and automount-dir-prefix
1298	     (string-match automount-dir-prefix filename)
1299	     (file-exists-p (file-name-directory
1300			     (substring filename (1- (match-end 0))))))
1301	(setq filename (substring filename (1- (match-end 0)))))
1302    (let ((tail directory-abbrev-alist))
1303      ;; If any elt of directory-abbrev-alist matches this name,
1304      ;; abbreviate accordingly.
1305      (while tail
1306	(if (string-match (car (car tail)) filename)
1307	    (setq filename
1308		  (concat (cdr (car tail)) (substring filename (match-end 0)))))
1309	(setq tail (cdr tail)))
1310      ;; Compute and save the abbreviated homedir name.
1311      ;; We defer computing this until the first time it's needed, to
1312      ;; give time for directory-abbrev-alist to be set properly.
1313      ;; We include a slash at the end, to avoid spurious matches
1314      ;; such as `/usr/foobar' when the home dir is `/usr/foo'.
1315      (or abbreviated-home-dir
1316	  (setq abbreviated-home-dir
1317		(let ((abbreviated-home-dir "$foo"))
1318		  (concat "^" (abbreviate-file-name (expand-file-name "~"))
1319			  "\\(/\\|\\'\\)"))))
1320
1321      ;; If FILENAME starts with the abbreviated homedir,
1322      ;; make it start with `~' instead.
1323      (if (and (string-match abbreviated-home-dir filename)
1324	       ;; If the home dir is just /, don't change it.
1325	       (not (and (= (match-end 0) 1)
1326			 (= (aref filename 0) ?/)))
1327	       ;; MS-DOS root directories can come with a drive letter;
1328	       ;; Novell Netware allows drive letters beyond `Z:'.
1329	       (not (and (or (eq system-type 'ms-dos)
1330			     (eq system-type 'cygwin)
1331			     (eq system-type 'windows-nt))
1332			 (save-match-data
1333			   (string-match "^[a-zA-`]:/$" filename)))))
1334	  (setq filename
1335		(concat "~"
1336			(match-string 1 filename)
1337			(substring filename (match-end 0)))))
1338      filename)))
1339
1340(defcustom find-file-not-true-dirname-list nil
1341  "List of logical names for which visiting shouldn't save the true dirname.
1342On VMS, when you visit a file using a logical name that searches a path,
1343you may or may not want the visited file name to record the specific
1344directory where the file was found.  If you *do not* want that, add the logical
1345name to this list as a string."
1346  :type '(repeat (string :tag "Name"))
1347  :group 'find-file)
1348
1349(defun find-buffer-visiting (filename &optional predicate)
1350  "Return the buffer visiting file FILENAME (a string).
1351This is like `get-file-buffer', except that it checks for any buffer
1352visiting the same file, possibly under a different name.
1353If PREDICATE is non-nil, only buffers satisfying it are eligible,
1354and others are ignored.
1355If there is no such live buffer, return nil."
1356  (let ((predicate (or predicate #'identity))
1357        (truename (abbreviate-file-name (file-truename filename))))
1358    (or (let ((buf (get-file-buffer filename)))
1359          (when (and buf (funcall predicate buf)) buf))
1360        (let ((list (buffer-list)) found)
1361          (while (and (not found) list)
1362            (save-excursion
1363              (set-buffer (car list))
1364              (if (and buffer-file-name
1365                       (string= buffer-file-truename truename)
1366                       (funcall predicate (current-buffer)))
1367                  (setq found (car list))))
1368            (setq list (cdr list)))
1369          found)
1370        (let* ((attributes (file-attributes truename))
1371               (number (nthcdr 10 attributes))
1372               (list (buffer-list)) found)
1373          (and buffer-file-numbers-unique
1374               (car-safe number)       ;Make sure the inode is not just nil.
1375               (while (and (not found) list)
1376                 (with-current-buffer (car list)
1377                   (if (and buffer-file-name
1378                            (equal buffer-file-number number)
1379                            ;; Verify this buffer's file number
1380                            ;; still belongs to its file.
1381                            (file-exists-p buffer-file-name)
1382                            (equal (file-attributes buffer-file-truename)
1383                                   attributes)
1384                            (funcall predicate (current-buffer)))
1385                       (setq found (car list))))
1386                 (setq list (cdr list))))
1387          found))))
1388
1389(defcustom find-file-wildcards t
1390  "Non-nil means file-visiting commands should handle wildcards.
1391For example, if you specify `*.c', that would visit all the files
1392whose names match the pattern."
1393  :group 'files
1394  :version "20.4"
1395  :type 'boolean)
1396
1397(defcustom find-file-suppress-same-file-warnings nil
1398  "Non-nil means suppress warning messages for symlinked files.
1399When nil, Emacs prints a warning when visiting a file that is already
1400visited, but with a different name.  Setting this option to t
1401suppresses this warning."
1402  :group 'files
1403  :version "21.1"
1404  :type 'boolean)
1405
1406(defcustom large-file-warning-threshold 10000000
1407  "Maximum size of file above which a confirmation is requested.
1408When nil, never request confirmation."
1409  :group 'files
1410  :group 'find-file
1411  :version "22.1"
1412  :type '(choice integer (const :tag "Never request confirmation" nil)))
1413
1414(defun find-file-noselect (filename &optional nowarn rawfile wildcards)
1415  "Read file FILENAME into a buffer and return the buffer.
1416If a buffer exists visiting FILENAME, return that one, but
1417verify that the file has not changed since visited or saved.
1418The buffer is not selected, just returned to the caller.
1419Optional second arg NOWARN non-nil means suppress any warning messages.
1420Optional third arg RAWFILE non-nil means the file is read literally.
1421Optional fourth arg WILDCARDS non-nil means do wildcard processing
1422and visit all the matching files.  When wildcards are actually
1423used and expanded, return a list of buffers that are visiting
1424the various files."
1425  (setq filename
1426	(abbreviate-file-name
1427	 (expand-file-name filename)))
1428  (if (file-directory-p filename)
1429      (or (and find-file-run-dired
1430	       (run-hook-with-args-until-success
1431		'find-directory-functions
1432		(if find-file-visit-truename
1433		    (abbreviate-file-name (file-truename filename))
1434		  filename)))
1435	  (error "%s is a directory" filename))
1436    (if (and wildcards
1437	     find-file-wildcards
1438	     (not (string-match "\\`/:" filename))
1439	     (string-match "[[*?]" filename))
1440	(let ((files (condition-case nil
1441			 (file-expand-wildcards filename t)
1442		       (error (list filename))))
1443	      (find-file-wildcards nil))
1444	  (if (null files)
1445	      (find-file-noselect filename)
1446	    (mapcar #'find-file-noselect files)))
1447      (let* ((buf (get-file-buffer filename))
1448	     (truename (abbreviate-file-name (file-truename filename)))
1449	     (attributes (file-attributes truename))
1450	     (number (nthcdr 10 attributes))
1451	     ;; Find any buffer for a file which has same truename.
1452	     (other (and (not buf) (find-buffer-visiting filename))))
1453	;; Let user know if there is a buffer with the same truename.
1454	(if other
1455	    (progn
1456	      (or nowarn
1457		  find-file-suppress-same-file-warnings
1458		  (string-equal filename (buffer-file-name other))
1459		  (message "%s and %s are the same file"
1460			   filename (buffer-file-name other)))
1461	      ;; Optionally also find that buffer.
1462	      (if (or find-file-existing-other-name find-file-visit-truename)
1463		  (setq buf other))))
1464	;; Check to see if the file looks uncommonly large.
1465	(when (and large-file-warning-threshold (nth 7 attributes)
1466		   ;; Don't ask again if we already have the file or
1467		   ;; if we're asked to be quiet.
1468		   (not (or buf nowarn))
1469		   (> (nth 7 attributes) large-file-warning-threshold)
1470		   (not (y-or-n-p
1471			 (format "File %s is large (%dMB), really open? "
1472				 (file-name-nondirectory filename)
1473				   (/ (nth 7 attributes) 1048576)))))
1474	  (error "Aborted"))
1475	(if buf
1476	    ;; We are using an existing buffer.
1477	    (let (nonexistent)
1478	      (or nowarn
1479		  (verify-visited-file-modtime buf)
1480		  (cond ((not (file-exists-p filename))
1481			 (setq nonexistent t)
1482			 (message "File %s no longer exists!" filename))
1483			;; Certain files should be reverted automatically
1484			;; if they have changed on disk and not in the buffer.
1485			((and (not (buffer-modified-p buf))
1486			      (let ((tail revert-without-query)
1487				    (found nil))
1488				(while tail
1489				  (if (string-match (car tail) filename)
1490				      (setq found t))
1491				  (setq tail (cdr tail)))
1492				found))
1493			 (with-current-buffer buf
1494			   (message "Reverting file %s..." filename)
1495			   (revert-buffer t t)
1496			   (message "Reverting file %s...done" filename)))
1497			((yes-or-no-p
1498			  (if (string= (file-name-nondirectory filename)
1499				       (buffer-name buf))
1500			      (format
1501			       (if (buffer-modified-p buf)
1502				   "File %s changed on disk.  Discard your edits? "
1503				 "File %s changed on disk.  Reread from disk? ")
1504			       (file-name-nondirectory filename))
1505			    (format
1506			     (if (buffer-modified-p buf)
1507				 "File %s changed on disk.  Discard your edits in %s? "
1508			       "File %s changed on disk.  Reread from disk into %s? ")
1509			     (file-name-nondirectory filename)
1510			     (buffer-name buf))))
1511			 (with-current-buffer buf
1512			   (revert-buffer t t)))))
1513	      (with-current-buffer buf
1514
1515		;; Check if a formerly read-only file has become
1516		;; writable and vice versa, but if the buffer agrees
1517		;; with the new state of the file, that is ok too.
1518		(let ((read-only (not (file-writable-p buffer-file-name))))
1519		  (unless (or nonexistent
1520			      (eq read-only buffer-file-read-only)
1521			      (eq read-only buffer-read-only))
1522		    (when (or nowarn
1523			      (let ((question
1524				     (format "File %s is %s on disk.  Change buffer mode? "
1525					     buffer-file-name
1526					     (if read-only "read-only" "writable"))))
1527				(y-or-n-p question)))
1528		      (setq buffer-read-only read-only)))
1529		  (setq buffer-file-read-only read-only))
1530
1531		(when (and (not (eq (not (null rawfile))
1532				    (not (null find-file-literally))))
1533			   (not nonexistent)
1534			   ;; It is confusing to ask whether to visit
1535			   ;; non-literally if they have the file in
1536			   ;; hexl-mode.
1537			   (not (eq major-mode 'hexl-mode)))
1538		  (if (buffer-modified-p)
1539		      (if (y-or-n-p
1540			   (format
1541			    (if rawfile
1542				"The file %s is already visited normally,
1543and you have edited the buffer.  Now you have asked to visit it literally,
1544meaning no coding system handling, format conversion, or local variables.
1545Emacs can only visit a file in one way at a time.
1546
1547Do you want to save the file, and visit it literally instead? "
1548				"The file %s is already visited literally,
1549meaning no coding system handling, format conversion, or local variables.
1550You have edited the buffer.  Now you have asked to visit the file normally,
1551but Emacs can only visit a file in one way at a time.
1552
1553Do you want to save the file, and visit it normally instead? ")
1554			    (file-name-nondirectory filename)))
1555			  (progn
1556			    (save-buffer)
1557			    (find-file-noselect-1 buf filename nowarn
1558						  rawfile truename number))
1559			(if (y-or-n-p
1560			     (format
1561			      (if rawfile
1562				  "\
1563Do you want to discard your changes, and visit the file literally now? "
1564				"\
1565Do you want to discard your changes, and visit the file normally now? ")))
1566			    (find-file-noselect-1 buf filename nowarn
1567						  rawfile truename number)
1568			  (error (if rawfile "File already visited non-literally"
1569				   "File already visited literally"))))
1570		    (if (y-or-n-p
1571			 (format
1572			  (if rawfile
1573			      "The file %s is already visited normally.
1574You have asked to visit it literally,
1575meaning no coding system decoding, format conversion, or local variables.
1576But Emacs can only visit a file in one way at a time.
1577
1578Do you want to revisit the file literally now? "
1579			    "The file %s is already visited literally,
1580meaning no coding system decoding, format conversion, or local variables.
1581You have asked to visit it normally,
1582but Emacs can only visit a file in one way at a time.
1583
1584Do you want to revisit the file normally now? ")
1585			  (file-name-nondirectory filename)))
1586			(find-file-noselect-1 buf filename nowarn
1587					      rawfile truename number)
1588		      (error (if rawfile "File already visited non-literally"
1589			       "File already visited literally"))))))
1590	      ;; Return the buffer we are using.
1591	      buf)
1592	  ;; Create a new buffer.
1593	  (setq buf (create-file-buffer filename))
1594	  ;; find-file-noselect-1 may use a different buffer.
1595	  (find-file-noselect-1 buf filename nowarn
1596				rawfile truename number))))))
1597
1598(defun find-file-noselect-1 (buf filename nowarn rawfile truename number)
1599  (let (error)
1600    (with-current-buffer buf
1601      (kill-local-variable 'find-file-literally)
1602      ;; Needed in case we are re-visiting the file with a different
1603      ;; text representation.
1604      (kill-local-variable 'buffer-file-coding-system)
1605      (kill-local-variable 'cursor-type)
1606      (let ((inhibit-read-only t))
1607	(erase-buffer))
1608      (and (default-value 'enable-multibyte-characters)
1609	   (not rawfile)
1610	   (set-buffer-multibyte t))
1611      (if rawfile
1612	  (condition-case ()
1613	      (let ((inhibit-read-only t))
1614		(insert-file-contents-literally filename t))
1615	    (file-error
1616	     (when (and (file-exists-p filename)
1617			(not (file-readable-p filename)))
1618	       (kill-buffer buf)
1619	       (signal 'file-error (list "File is not readable"
1620					 filename)))
1621	     ;; Unconditionally set error
1622	     (setq error t)))
1623	(condition-case ()
1624	    (let ((inhibit-read-only t))
1625	      (insert-file-contents filename t))
1626	  (file-error
1627	   (when (and (file-exists-p filename)
1628		      (not (file-readable-p filename)))
1629	     (kill-buffer buf)
1630	     (signal 'file-error (list "File is not readable"
1631				       filename)))
1632	   ;; Run find-file-not-found-functions until one returns non-nil.
1633	   (or (run-hook-with-args-until-success 'find-file-not-found-functions)
1634	       ;; If they fail too, set error.
1635	       (setq error t)))))
1636      ;; Record the file's truename, and maybe use that as visited name.
1637      (if (equal filename buffer-file-name)
1638	  (setq buffer-file-truename truename)
1639	(setq buffer-file-truename
1640	      (abbreviate-file-name (file-truename buffer-file-name))))
1641      (setq buffer-file-number number)
1642      ;; On VMS, we may want to remember which directory in a search list
1643      ;; the file was found in.
1644      (and (eq system-type 'vax-vms)
1645	   (let (logical)
1646	     (if (string-match ":" (file-name-directory filename))
1647		 (setq logical (substring (file-name-directory filename)
1648					  0 (match-beginning 0))))
1649	     (not (member logical find-file-not-true-dirname-list)))
1650	   (setq buffer-file-name buffer-file-truename))
1651      (if find-file-visit-truename
1652	  (setq buffer-file-name (expand-file-name buffer-file-truename)))
1653      ;; Set buffer's default directory to that of the file.
1654      (setq default-directory (file-name-directory buffer-file-name))
1655      ;; Turn off backup files for certain file names.  Since
1656      ;; this is a permanent local, the major mode won't eliminate it.
1657      (and backup-enable-predicate
1658	   (not (funcall backup-enable-predicate buffer-file-name))
1659	   (progn
1660	     (make-local-variable 'backup-inhibited)
1661	     (setq backup-inhibited t)))
1662      (if rawfile
1663	  (progn
1664	    (set-buffer-multibyte nil)
1665	    (setq buffer-file-coding-system 'no-conversion)
1666	    (set-buffer-major-mode buf)
1667	    (make-local-variable 'find-file-literally)
1668	    (setq find-file-literally t))
1669	(after-find-file error (not nowarn)))
1670      (current-buffer))))
1671
1672(defun insert-file-contents-literally (filename &optional visit beg end replace)
1673  "Like `insert-file-contents', but only reads in the file literally.
1674A buffer may be modified in several ways after reading into the buffer,
1675to Emacs features such as format decoding, character code
1676conversion, `find-file-hook', automatic uncompression, etc.
1677
1678This function ensures that none of these modifications will take place."
1679  (let ((format-alist nil)
1680	(after-insert-file-functions nil)
1681	(coding-system-for-read 'no-conversion)
1682	(coding-system-for-write 'no-conversion)
1683	(find-buffer-file-type-function
1684         (if (fboundp 'find-buffer-file-type)
1685             (symbol-function 'find-buffer-file-type)
1686           nil))
1687        (inhibit-file-name-handlers
1688         (append '(jka-compr-handler image-file-handler)
1689                 inhibit-file-name-handlers))
1690        (inhibit-file-name-operation 'insert-file-contents))
1691    (unwind-protect
1692         (progn
1693           (fset 'find-buffer-file-type (lambda (filename) t))
1694           (insert-file-contents filename visit beg end replace))
1695      (if find-buffer-file-type-function
1696	  (fset 'find-buffer-file-type find-buffer-file-type-function)
1697	(fmakunbound 'find-buffer-file-type)))))
1698
1699(defun insert-file-1 (filename insert-func)
1700  (if (file-directory-p filename)
1701      (signal 'file-error (list "Opening input file" "file is a directory"
1702                                filename)))
1703  (let* ((buffer (find-buffer-visiting (abbreviate-file-name (file-truename filename))
1704                                       #'buffer-modified-p))
1705         (tem (funcall insert-func filename)))
1706    (push-mark (+ (point) (car (cdr tem))))
1707    (when buffer
1708      (message "File %s already visited and modified in buffer %s"
1709               filename (buffer-name buffer)))))
1710
1711(defun insert-file-literally (filename)
1712  "Insert contents of file FILENAME into buffer after point with no conversion.
1713
1714This function is meant for the user to run interactively.
1715Don't call it from programs!  Use `insert-file-contents-literally' instead.
1716\(Its calling sequence is different; see its documentation)."
1717  (interactive "*fInsert file literally: ")
1718  (insert-file-1 filename #'insert-file-contents-literally))
1719
1720(defvar find-file-literally nil
1721  "Non-nil if this buffer was made by `find-file-literally' or equivalent.
1722This is a permanent local.")
1723(put 'find-file-literally 'permanent-local t)
1724
1725(defun find-file-literally (filename)
1726  "Visit file FILENAME with no conversion of any kind.
1727Format conversion and character code conversion are both disabled,
1728and multibyte characters are disabled in the resulting buffer.
1729The major mode used is Fundamental mode regardless of the file name,
1730and local variable specifications in the file are ignored.
1731Automatic uncompression and adding a newline at the end of the
1732file due to `require-final-newline' is also disabled.
1733
1734You cannot absolutely rely on this function to result in
1735visiting the file literally.  If Emacs already has a buffer
1736which is visiting the file, you get the existing buffer,
1737regardless of whether it was created literally or not.
1738
1739In a Lisp program, if you want to be sure of accessing a file's
1740contents literally, you should create a temporary buffer and then read
1741the file contents into it using `insert-file-contents-literally'."
1742  (interactive "FFind file literally: ")
1743  (switch-to-buffer (find-file-noselect filename nil t)))
1744
1745(defvar after-find-file-from-revert-buffer nil)
1746
1747(defun after-find-file (&optional error warn noauto
1748				  after-find-file-from-revert-buffer
1749				  nomodes)
1750  "Called after finding a file and by the default revert function.
1751Sets buffer mode, parses local variables.
1752Optional args ERROR, WARN, and NOAUTO: ERROR non-nil means there was an
1753error in reading the file.  WARN non-nil means warn if there
1754exists an auto-save file more recent than the visited file.
1755NOAUTO means don't mess with auto-save mode.
1756Fourth arg AFTER-FIND-FILE-FROM-REVERT-BUFFER non-nil
1757 means this call was from `revert-buffer'.
1758Fifth arg NOMODES non-nil means don't alter the file's modes.
1759Finishes by calling the functions in `find-file-hook'
1760unless NOMODES is non-nil."
1761  (setq buffer-read-only (not (file-writable-p buffer-file-name)))
1762  (if noninteractive
1763      nil
1764    (let* (not-serious
1765	   (msg
1766	    (cond
1767	     ((not warn) nil)
1768	     ((and error (file-attributes buffer-file-name))
1769	      (setq buffer-read-only t)
1770	      "File exists, but cannot be read")
1771	     ((not buffer-read-only)
1772	      (if (and warn
1773		       ;; No need to warn if buffer is auto-saved
1774		       ;; under the name of the visited file.
1775		       (not (and buffer-file-name
1776				 auto-save-visited-file-name))
1777		       (file-newer-than-file-p (or buffer-auto-save-file-name
1778						   (make-auto-save-file-name))
1779					       buffer-file-name))
1780		  (format "%s has auto save data; consider M-x recover-this-file"
1781			  (file-name-nondirectory buffer-file-name))
1782		(setq not-serious t)
1783		(if error "(New file)" nil)))
1784	     ((not error)
1785	      (setq not-serious t)
1786	      "Note: file is write protected")
1787	     ((file-attributes (directory-file-name default-directory))
1788	      "File not found and directory write-protected")
1789	     ((file-exists-p (file-name-directory buffer-file-name))
1790	      (setq buffer-read-only nil))
1791	     (t
1792	      (setq buffer-read-only nil)
1793	      "Use M-x make-directory RET RET to create the directory and its parents"))))
1794      (when msg
1795	(message "%s" msg)
1796	(or not-serious (sit-for 1 t))))
1797    (when (and auto-save-default (not noauto))
1798      (auto-save-mode t)))
1799  ;; Make people do a little extra work (C-x C-q)
1800  ;; before altering a backup file.
1801  (when (backup-file-name-p buffer-file-name)
1802    (setq buffer-read-only t))
1803  ;; When a file is marked read-only,
1804  ;; make the buffer read-only even if root is looking at it.
1805  (when (and (file-modes (buffer-file-name))
1806	     (zerop (logand (file-modes (buffer-file-name)) #o222)))
1807    (setq buffer-read-only t))
1808  (unless nomodes
1809    (when (and view-read-only view-mode)
1810      (view-mode-disable))
1811    (normal-mode t)
1812    ;; If requested, add a newline at the end of the file.
1813    (and (memq require-final-newline '(visit visit-save))
1814	 (> (point-max) (point-min))
1815	 (/= (char-after (1- (point-max))) ?\n)
1816	 (not (and (eq selective-display t)
1817		   (= (char-after (1- (point-max))) ?\r)))
1818	 (save-excursion
1819	   (goto-char (point-max))
1820	   (insert "\n")))
1821    (when (and buffer-read-only
1822	       view-read-only
1823	       (not (eq (get major-mode 'mode-class) 'special)))
1824      (view-mode-enter))
1825    (run-hooks 'find-file-hook)))
1826
1827(defmacro report-errors (format &rest body)
1828  "Eval BODY and turn any error into a FORMAT message.
1829FORMAT can have a %s escape which will be replaced with the actual error.
1830If `debug-on-error' is set, errors are not caught, so that you can
1831debug them.
1832Avoid using a large BODY since it is duplicated."
1833  (declare (debug t) (indent 1))
1834  `(if debug-on-error
1835       (progn . ,body)
1836     (condition-case err
1837	 (progn . ,body)
1838       (error (message ,format (prin1-to-string err))))))
1839
1840(defun normal-mode (&optional find-file)
1841  "Choose the major mode for this buffer automatically.
1842Also sets up any specified local variables of the file.
1843Uses the visited file name, the -*- line, and the local variables spec.
1844
1845This function is called automatically from `find-file'.  In that case,
1846we may set up the file-specified mode and local variables,
1847depending on the value of `enable-local-variables'.
1848In addition, if `local-enable-local-variables' is nil, we do
1849not set local variables (though we do notice a mode specified with -*-.)
1850
1851`enable-local-variables' is ignored if you run `normal-mode' interactively,
1852or from Lisp without specifying the optional argument FIND-FILE;
1853in that case, this function acts as if `enable-local-variables' were t."
1854  (interactive)
1855  (funcall (or default-major-mode 'fundamental-mode))
1856  (let ((enable-local-variables (or (not find-file) enable-local-variables)))
1857    (report-errors "File mode specification error: %s"
1858      (set-auto-mode))
1859    (report-errors "File local-variables error: %s"
1860      (hack-local-variables)))
1861  ;; Turn font lock off and on, to make sure it takes account of
1862  ;; whatever file local variables are relevant to it.
1863  (when (and font-lock-mode
1864             ;; Font-lock-mode (now in font-core.el) can be ON when
1865             ;; font-lock.el still hasn't been loaded.
1866             (boundp 'font-lock-keywords)
1867             (eq (car font-lock-keywords) t))
1868    (setq font-lock-keywords (cadr font-lock-keywords))
1869    (font-lock-mode 1))
1870
1871  (if (fboundp 'ucs-set-table-for-input) ; don't lose when building
1872      (ucs-set-table-for-input)))
1873
1874(defcustom auto-mode-case-fold nil
1875  "Non-nil means to try second pass through `auto-mode-alist'.
1876This means that if the first case-sensitive search through the alist fails
1877to find a matching major mode, a second case-insensitive search is made.
1878On systems with case-insensitive file names, this variable is ignored,
1879since only a single case-insensitive search through the alist is made."
1880  :group 'files
1881  :version "22.1"
1882  :type 'boolean)
1883
1884(defvar auto-mode-alist
1885  ;; Note: The entries for the modes defined in cc-mode.el (c-mode,
1886  ;; c++-mode, java-mode and more) are added through autoload
1887  ;; directives in that file.  That way is discouraged since it
1888  ;; spreads out the definition of the initial value.
1889  (mapc
1890   (lambda (elt)
1891     (cons (purecopy (car elt)) (cdr elt)))
1892   `(;; do this first, so that .html.pl is Polish html, not Perl
1893     ("\\.s?html?\\(\\.[a-zA-Z_]+\\)?\\'" . html-mode)
1894     ("\\.te?xt\\'" . text-mode)
1895     ("\\.[tT]e[xX]\\'" . tex-mode)
1896     ("\\.ins\\'" . tex-mode)		;Installation files for TeX packages.
1897     ("\\.ltx\\'" . latex-mode)
1898     ("\\.dtx\\'" . doctex-mode)
1899     ("\\.el\\'" . emacs-lisp-mode)
1900     ("\\.\\(scm\\|stk\\|ss\\|sch\\)\\'" . scheme-mode)
1901     ("\\.l\\'" . lisp-mode)
1902     ("\\.li?sp\\'" . lisp-mode)
1903     ("\\.[fF]\\'" . fortran-mode)
1904     ("\\.for\\'" . fortran-mode)
1905     ("\\.p\\'" . pascal-mode)
1906     ("\\.pas\\'" . pascal-mode)
1907     ("\\.ad[abs]\\'" . ada-mode)
1908     ("\\.ad[bs].dg\\'" . ada-mode)
1909     ("\\.\\([pP]\\([Llm]\\|erl\\|od\\)\\|al\\)\\'" . perl-mode)
1910     ("Imakefile\\'" . makefile-imake-mode)
1911     ("Makeppfile\\(?:\\.mk\\)?\\'" . makefile-makepp-mode) ; Put this before .mk
1912     ("\\.makepp\\'" . makefile-makepp-mode)
1913     ,@(if (memq system-type '(berkeley-unix next-mach darwin))
1914	   '(("\\.mk\\'" . makefile-bsdmake-mode)
1915	     ("GNUmakefile\\'" . makefile-gmake-mode)
1916	     ("[Mm]akefile\\'" . makefile-bsdmake-mode))
1917	 '(("\\.mk\\'" . makefile-gmake-mode)	; Might be any make, give Gnu the host advantage
1918	   ("[Mm]akefile\\'" . makefile-gmake-mode)))
1919     ("\\.am\\'" . makefile-automake-mode)
1920     ;; Less common extensions come here
1921     ;; so more common ones above are found faster.
1922     ("\\.texinfo\\'" . texinfo-mode)
1923     ("\\.te?xi\\'" . texinfo-mode)
1924     ("\\.[sS]\\'" . asm-mode)
1925     ("\\.asm\\'" . asm-mode)
1926     ("[cC]hange\\.?[lL]og?\\'" . change-log-mode)
1927     ("[cC]hange[lL]og[-.][0-9]+\\'" . change-log-mode)
1928     ("\\$CHANGE_LOG\\$\\.TXT" . change-log-mode)
1929     ("\\.scm\\.[0-9]*\\'" . scheme-mode)
1930     ("\\.[ck]?sh\\'\\|\\.shar\\'\\|/\\.z?profile\\'" . sh-mode)
1931     ("\\.bash\\'" . sh-mode)
1932     ("\\(/\\|\\`\\)\\.\\(bash_profile\\|z?login\\|bash_login\\|z?logout\\)\\'" . sh-mode)
1933     ("\\(/\\|\\`\\)\\.\\(bash_logout\\|shrc\\|[kz]shrc\\|bashrc\\|t?cshrc\\|esrc\\)\\'" . sh-mode)
1934     ("\\(/\\|\\`\\)\\.\\([kz]shenv\\|xinitrc\\|startxrc\\|xsession\\)\\'" . sh-mode)
1935     ("\\.m?spec\\'" . sh-mode)
1936     ("\\.m[mes]\\'" . nroff-mode)
1937     ("\\.man\\'" . nroff-mode)
1938     ("\\.sty\\'" . latex-mode)
1939     ("\\.cl[so]\\'" . latex-mode)		;LaTeX 2e class option
1940     ("\\.bbl\\'" . latex-mode)
1941     ("\\.bib\\'" . bibtex-mode)
1942     ("\\.sql\\'" . sql-mode)
1943     ("\\.m[4c]\\'" . m4-mode)
1944     ("\\.mf\\'" . metafont-mode)
1945     ("\\.mp\\'" . metapost-mode)
1946     ("\\.vhdl?\\'" . vhdl-mode)
1947     ("\\.article\\'" . text-mode)
1948     ("\\.letter\\'" . text-mode)
1949     ("\\.i?tcl\\'" . tcl-mode)
1950     ("\\.exp\\'" . tcl-mode)
1951     ("\\.itk\\'" . tcl-mode)
1952     ("\\.icn\\'" . icon-mode)
1953     ("\\.sim\\'" . simula-mode)
1954     ("\\.mss\\'" . scribe-mode)
1955     ("\\.f9[05]\\'" . f90-mode)
1956     ("\\.indent\\.pro\\'" . fundamental-mode) ; to avoid idlwave-mode
1957     ("\\.pro\\'" . idlwave-mode)
1958     ("\\.prolog\\'" . prolog-mode)
1959     ("\\.tar\\'" . tar-mode)
1960     ;; The list of archive file extensions should be in sync with
1961     ;; `auto-coding-alist' with `no-conversion' coding system.
1962     ("\\.\\(arc\\|zip\\|lzh\\|lha\\|zoo\\|[jew]ar\\|xpi\\)\\'" . archive-mode)
1963     ("\\.\\(ARC\\|ZIP\\|LZH\\|LHA\\|ZOO\\|[JEW]AR\\|XPI\\)\\'" . archive-mode)
1964     ("\\.\\(sx[dmicw]\\|odt\\)\\'" . archive-mode)	; OpenOffice.org
1965     ;; Mailer puts message to be edited in
1966     ;; /tmp/Re.... or Message
1967     ("\\`/tmp/Re" . text-mode)
1968     ("/Message[0-9]*\\'" . text-mode)
1969     ("\\.zone\\'" . zone-mode)
1970     ;; some news reader is reported to use this
1971     ("\\`/tmp/fol/" . text-mode)
1972     ("\\.oak\\'" . scheme-mode)
1973     ("\\.sgml?\\'" . sgml-mode)
1974     ("\\.x[ms]l\\'" . xml-mode)
1975     ("\\.dtd\\'" . sgml-mode)
1976     ("\\.ds\\(ss\\)?l\\'" . dsssl-mode)
1977     ("\\.js\\'" . java-mode)		; javascript-mode would be better
1978     ("\\.x[bp]m\\'" . c-mode)
1979     ;; .emacs or .gnus or .viper following a directory delimiter in
1980     ;; Unix, MSDOG or VMS syntax.
1981     ("[]>:/\\]\\..*\\(emacs\\|gnus\\|viper\\)\\'" . emacs-lisp-mode)
1982     ("\\`\\..*emacs\\'" . emacs-lisp-mode)
1983     ;; _emacs following a directory delimiter
1984     ;; in MsDos syntax
1985     ("[:/]_emacs\\'" . emacs-lisp-mode)
1986     ("/crontab\\.X*[0-9]+\\'" . shell-script-mode)
1987     ("\\.ml\\'" . lisp-mode)
1988     ("\\.\\(asn\\|mib\\|smi\\)\\'" . snmp-mode)
1989     ("\\.\\(as\\|mi\\|sm\\)2\\'" . snmpv2-mode)
1990     ("\\.\\(diffs?\\|patch\\|rej\\)\\'" . diff-mode)
1991     ("\\.\\(dif\\|pat\\)\\'" . diff-mode) ; for MSDOG
1992     ("\\.[eE]?[pP][sS]\\'" . ps-mode)
1993     ("configure\\.\\(ac\\|in\\)\\'" . autoconf-mode)
1994     ("BROWSE\\'" . ebrowse-tree-mode)
1995     ("\\.ebrowse\\'" . ebrowse-tree-mode)
1996     ("#\\*mail\\*" . mail-mode)
1997     ("\\.g\\'" . antlr-mode)
1998     ("\\.ses\\'" . ses-mode)
1999     ("\\.\\(soa\\|zone\\)\\'" . dns-mode)
2000     ("\\.docbook\\'" . sgml-mode)
2001     ("\\.com\\'" . dcl-mode)
2002     ("/config\\.\\(?:bat\\|log\\)\\'" . fundamental-mode)
2003     ;; Windows candidates may be opened case sensitively on Unix
2004     ("\\.\\(?:[iI][nN][iI]\\|[lL][sS][tT]\\|[rR][eE][gG]\\|[sS][yY][sS]\\)\\'" . conf-mode)
2005     ("\\.\\(?:desktop\\|la\\)\\'" . conf-unix-mode)
2006     ("\\.ppd\\'" . conf-ppd-mode)
2007     ("java.+\\.conf\\'" . conf-javaprop-mode)
2008     ("\\.properties\\(?:\\.[a-zA-Z0-9._-]+\\)?\\'" . conf-javaprop-mode)
2009     ;; *.cf, *.cfg, *.conf, *.config[.local|.de_DE.UTF8|...], */config
2010     ("[/.]c\\(?:on\\)?f\\(?:i?g\\)?\\(?:\\.[a-zA-Z0-9._-]+\\)?\\'" . conf-mode)
2011     ("\\`/etc/\\(?:DIR_COLORS\\|ethers\\|.?fstab\\|.*hosts\\|lesskey\\|login\\.?de\\(?:fs\\|vperm\\)\\|magic\\|mtab\\|pam\\.d/.*\\|permissions\\(?:\\.d/.+\\)?\\|protocols\\|rpc\\|services\\)\\'" . conf-space-mode)
2012     ("\\`/etc/\\(?:acpid?/.+\\|aliases\\(?:\\.d/.+\\)?\\|default/.+\\|group-?\\|hosts\\..+\\|inittab\\|ksysguarddrc\\|opera6rc\\|passwd-?\\|shadow-?\\|sysconfig/.+\\)\\'" . conf-mode)
2013     ;; either user's dot-files or under /etc or some such
2014     ("/\\.?\\(?:gnokiirc\\|kde.*rc\\|mime\\.types\\|wgetrc\\)\\'" . conf-mode)
2015     ;; alas not all ~/.*rc files are like this
2016     ("/\\.\\(?:enigma\\|gltron\\|gtk\\|hxplayer\\|net\\|neverball\\|qt/.+\\|realplayer\\|scummvm\\|sversion\\|sylpheed/.+\\|xmp\\)rc\\'" . conf-mode)
2017     ("/\\.\\(?:gdbtkinit\\|grip\\|orbital/.+txt\\|rhosts\\|tuxracer/options\\)\\'" . conf-mode)
2018     ("/\\.?X\\(?:default\\|resource\\|re\\)s\\>" . conf-xdefaults-mode)
2019     ("/X11.+app-defaults/" . conf-xdefaults-mode)
2020     ("/X11.+locale/.+/Compose\\'" . conf-colon-mode)
2021     ;; this contains everything twice, with space and with colon :-(
2022     ("/X11.+locale/compose\\.dir\\'" . conf-javaprop-mode)
2023     ;; Get rid of any trailing .n.m and try again.
2024     ;; This is for files saved by cvs-merge that look like .#<file>.<rev>
2025     ;; or .#<file>.<rev>-<rev> or VC's <file>.~<rev>~.
2026     ;; Using mode nil rather than `ignore' would let the search continue
2027     ;; through this list (with the shortened name) rather than start over.
2028     ("\\.~?[0-9]+\\.[0-9][-.0-9]*~?\\'" nil t)
2029     ;; The following should come after the ChangeLog pattern
2030     ;; for the sake of ChangeLog.1, etc.
2031     ;; and after the .scm.[0-9] and CVS' <file>.<rev> patterns too.
2032     ("\\.[1-9]\\'" . nroff-mode)
2033     ("\\.\\(?:orig\\|in\\|[bB][aA][kK]\\)\\'" nil t)))
2034  "Alist of filename patterns vs corresponding major mode functions.
2035Each element looks like (REGEXP . FUNCTION) or (REGEXP FUNCTION NON-NIL).
2036\(NON-NIL stands for anything that is not nil; the value does not matter.)
2037Visiting a file whose name matches REGEXP specifies FUNCTION as the
2038mode function to use.  FUNCTION will be called, unless it is nil.
2039
2040If the element has the form (REGEXP FUNCTION NON-NIL), then after
2041calling FUNCTION (if it's not nil), we delete the suffix that matched
2042REGEXP and search the list again for another match.
2043
2044If the file name matches `inhibit-first-line-modes-regexps',
2045then `auto-mode-alist' is not processed.
2046
2047The extensions whose FUNCTION is `archive-mode' should also
2048appear in `auto-coding-alist' with `no-conversion' coding system.
2049
2050See also `interpreter-mode-alist', which detects executable script modes
2051based on the interpreters they specify to run,
2052and `magic-mode-alist', which determines modes based on file contents.")
2053
2054(defvar interpreter-mode-alist
2055  ;; Note: The entries for the modes defined in cc-mode.el (awk-mode
2056  ;; and pike-mode) are added through autoload directives in that
2057  ;; file.  That way is discouraged since it spreads out the
2058  ;; definition of the initial value.
2059  (mapc
2060   (lambda (l)
2061     (cons (purecopy (car l)) (cdr l)))
2062   '(("perl" . perl-mode)
2063     ("perl5" . perl-mode)
2064     ("miniperl" . perl-mode)
2065     ("wish" . tcl-mode)
2066     ("wishx" . tcl-mode)
2067     ("tcl" . tcl-mode)
2068     ("tclsh" . tcl-mode)
2069     ("scm" . scheme-mode)
2070     ("ash" . sh-mode)
2071     ("bash" . sh-mode)
2072     ("bash2" . sh-mode)
2073     ("csh" . sh-mode)
2074     ("dtksh" . sh-mode)
2075     ("es" . sh-mode)
2076     ("itcsh" . sh-mode)
2077     ("jsh" . sh-mode)
2078     ("ksh" . sh-mode)
2079     ("oash" . sh-mode)
2080     ("pdksh" . sh-mode)
2081     ("rc" . sh-mode)
2082     ("rpm" . sh-mode)
2083     ("sh" . sh-mode)
2084     ("sh5" . sh-mode)
2085     ("tcsh" . sh-mode)
2086     ("wksh" . sh-mode)
2087     ("wsh" . sh-mode)
2088     ("zsh" . sh-mode)
2089     ("tail" . text-mode)
2090     ("more" . text-mode)
2091     ("less" . text-mode)
2092     ("pg" . text-mode)
2093     ("make" . makefile-gmake-mode)		; Debian uses this
2094     ("guile" . scheme-mode)
2095     ("clisp" . lisp-mode)))
2096  "Alist mapping interpreter names to major modes.
2097This is used for files whose first lines match `auto-mode-interpreter-regexp'.
2098Each element looks like (INTERPRETER . MODE).
2099If INTERPRETER matches the name of the interpreter specified in the first line
2100of a script, mode MODE is enabled.
2101
2102See also `auto-mode-alist'.")
2103
2104(defvar inhibit-first-line-modes-regexps '("\\.tar\\'" "\\.tgz\\'")
2105  "List of regexps; if one matches a file name, don't look for `-*-'.")
2106
2107(defvar inhibit-first-line-modes-suffixes nil
2108  "List of regexps for what to ignore, for `inhibit-first-line-modes-regexps'.
2109When checking `inhibit-first-line-modes-regexps', we first discard
2110from the end of the file name anything that matches one of these regexps.")
2111
2112(defvar auto-mode-interpreter-regexp
2113  "#![ \t]?\\([^ \t\n]*\
2114/bin/env[ \t]\\)?\\([^ \t\n]+\\)"
2115  "Regexp matching interpreters, for file mode determination.
2116This regular expression is matched against the first line of a file
2117to determine the file's mode in `set-auto-mode'.  If it matches, the file
2118is assumed to be interpreted by the interpreter matched by the second group
2119of the regular expression.  The mode is then determined as the mode
2120associated with that interpreter in `interpreter-mode-alist'.")
2121
2122(defvar magic-mode-alist
2123  `((image-type-auto-detected-p . image-mode))
2124  "Alist of buffer beginnings vs. corresponding major mode functions.
2125Each element looks like (REGEXP . FUNCTION) or (MATCH-FUNCTION . FUNCTION).
2126After visiting a file, if REGEXP matches the text at the beginning of the
2127buffer, or calling MATCH-FUNCTION returns non-nil, `normal-mode' will
2128call FUNCTION rather than allowing `auto-mode-alist' to decide the buffer's
2129major mode.
2130
2131If FUNCTION is nil, then it is not called.  (That is a way of saying
2132\"allow `auto-mode-alist' to decide for these files.\")")
2133(put 'magic-mode-alist 'risky-local-variable t)
2134
2135(defvar magic-fallback-mode-alist
2136  `(;; The < comes before the groups (but the first) to reduce backtracking.
2137    ;; TODO: UTF-16 <?xml may be preceded by a BOM 0xff 0xfe or 0xfe 0xff.
2138    ;; We use [ \t\r\n] instead of `\\s ' to make regex overflow less likely.
2139    (,(let* ((incomment-re "\\(?:[^-]\\|-[^-]\\)")
2140	     (comment-re (concat "\\(?:!--" incomment-re "*-->[ \t\r\n]*<\\)")))
2141	(concat "\\(?:<\\?xml[ \t\r\n]+[^>]*>\\)?[ \t\r\n]*<"
2142		comment-re "*"
2143		"\\(?:!DOCTYPE[ \t\r\n]+[^>]*>[ \t\r\n]*<[ \t\r\n]*" comment-re "*\\)?"
2144		"[Hh][Tt][Mm][Ll]"))
2145     . html-mode)
2146    ("<!DOCTYPE[ \t\r\n]+[Hh][Tt][Mm][Ll]" . html-mode)
2147    ;; These two must come after html, because they are more general:
2148    ("<\\?xml " . xml-mode)
2149    (,(let* ((incomment-re "\\(?:[^-]\\|-[^-]\\)")
2150	     (comment-re (concat "\\(?:!--" incomment-re "*-->[ \t\r\n]*<\\)")))
2151	(concat "[ \t\r\n]*<" comment-re "*!DOCTYPE "))
2152     . sgml-mode)
2153    ("%!PS" . ps-mode)
2154    ("# xmcd " . conf-unix-mode))
2155  "Like `magic-mode-alist' but has lower priority than `auto-mode-alist'.
2156Each element looks like (REGEXP . FUNCTION) or (MATCH-FUNCTION . FUNCTION).
2157After visiting a file, if REGEXP matches the text at the beginning of the
2158buffer, or calling MATCH-FUNCTION returns non-nil, `normal-mode' will
2159call FUNCTION, provided that `magic-mode-alist' and `auto-mode-alist'
2160have not specified a mode for this file.
2161
2162If FUNCTION is nil, then it is not called.")
2163(put 'magic-fallback-mode-alist 'risky-local-variable t)
2164
2165(defvar magic-mode-regexp-match-limit 4000
2166  "Upper limit on `magic-mode-alist' regexp matches.
2167Also applies to `magic-fallback-mode-alist'.")
2168
2169(defun set-auto-mode (&optional keep-mode-if-same)
2170  "Select major mode appropriate for current buffer.
2171
2172To find the right major mode, this function checks for a -*- mode tag,
2173checks if it uses an interpreter listed in `interpreter-mode-alist',
2174matches the buffer beginning against `magic-mode-alist',
2175compares the filename against the entries in `auto-mode-alist',
2176then matches the buffer beginning against `magic-fallback-mode-alist'.
2177
2178It does not check for the `mode:' local variable in the
2179Local Variables section of the file; for that, use `hack-local-variables'.
2180
2181If `enable-local-variables' is nil, this function does not check for a
2182-*- mode tag.
2183
2184If the optional argument KEEP-MODE-IF-SAME is non-nil, then we
2185set the major mode only if that would change it.  In other words
2186we don't actually set it to the same mode the buffer already has."
2187  ;; Look for -*-MODENAME-*- or -*- ... mode: MODENAME; ... -*-
2188  (let (end done mode modes)
2189    ;; Find a -*- mode tag
2190    (save-excursion
2191      (goto-char (point-min))
2192      (skip-chars-forward " \t\n")
2193      (and enable-local-variables
2194	   (setq end (set-auto-mode-1))
2195	   (if (save-excursion (search-forward ":" end t))
2196	       ;; Find all specifications for the `mode:' variable
2197	       ;; and execute them left to right.
2198	       (while (let ((case-fold-search t))
2199			(or (and (looking-at "mode:")
2200				 (goto-char (match-end 0)))
2201			    (re-search-forward "[ \t;]mode:" end t)))
2202		 (skip-chars-forward " \t")
2203		 (let ((beg (point)))
2204		   (if (search-forward ";" end t)
2205		       (forward-char -1)
2206		     (goto-char end))
2207		   (skip-chars-backward " \t")
2208		   (push (intern (concat (downcase (buffer-substring beg (point))) "-mode"))
2209			 modes)))
2210	     ;; Simple -*-MODE-*- case.
2211	     (push (intern (concat (downcase (buffer-substring (point) end))
2212				   "-mode"))
2213		   modes))))
2214    ;; If we found modes to use, invoke them now, outside the save-excursion.
2215    (if modes
2216	(catch 'nop
2217	  (dolist (mode (nreverse modes))
2218	    (if (not (functionp mode))
2219		(message "Ignoring unknown mode `%s'" mode)
2220	      (setq done t)
2221	      (or (set-auto-mode-0 mode keep-mode-if-same)
2222		  ;; continuing would call minor modes again, toggling them off
2223		  (throw 'nop nil))))))
2224    ;; If we didn't, look for an interpreter specified in the first line.
2225    ;; As a special case, allow for things like "#!/bin/env perl", which
2226    ;; finds the interpreter anywhere in $PATH.
2227    (unless done
2228      (setq mode (save-excursion
2229		   (goto-char (point-min))
2230		   (if (looking-at auto-mode-interpreter-regexp)
2231		       (match-string 2)
2232		     ""))
2233	    ;; Map interpreter name to a mode, signalling we're done at the
2234	    ;; same time.
2235	    done (assoc (file-name-nondirectory mode)
2236			interpreter-mode-alist))
2237      ;; If we found an interpreter mode to use, invoke it now.
2238      (if done
2239	  (set-auto-mode-0 (cdr done) keep-mode-if-same)))
2240    ;; Next try matching the buffer beginning against magic-mode-alist.
2241    (unless done
2242      (if (setq done (save-excursion
2243		       (goto-char (point-min))
2244		       (save-restriction
2245			 (narrow-to-region (point-min)
2246					   (min (point-max)
2247						(+ (point-min) magic-mode-regexp-match-limit)))
2248			 (assoc-default nil magic-mode-alist
2249					(lambda (re dummy)
2250					  (if (functionp re)
2251					      (funcall re)
2252					    (looking-at re)))))))
2253	  (set-auto-mode-0 done keep-mode-if-same)))
2254    ;; Next compare the filename against the entries in auto-mode-alist.
2255    (unless done
2256      (if buffer-file-name
2257	  (let ((name buffer-file-name))
2258	    ;; Remove backup-suffixes from file name.
2259	    (setq name (file-name-sans-versions name))
2260	    (while name
2261	      ;; Find first matching alist entry.
2262	      (setq mode
2263		    (if (memq system-type '(vax-vms windows-nt cygwin))
2264			;; System is case-insensitive.
2265			(let ((case-fold-search t))
2266			  (assoc-default name auto-mode-alist
2267					 'string-match))
2268		      ;; System is case-sensitive.
2269		      (or
2270		       ;; First match case-sensitively.
2271		       (let ((case-fold-search nil))
2272			 (assoc-default name auto-mode-alist
2273					'string-match))
2274		       ;; Fallback to case-insensitive match.
2275		       (and auto-mode-case-fold
2276			    (let ((case-fold-search t))
2277			      (assoc-default name auto-mode-alist
2278					     'string-match))))))
2279	      (if (and mode
2280		       (consp mode)
2281		       (cadr mode))
2282		  (setq mode (car mode)
2283			name (substring name 0 (match-beginning 0)))
2284		(setq name))
2285	      (when mode
2286		(set-auto-mode-0 mode keep-mode-if-same)
2287		(setq done t))))))
2288    ;; Next try matching the buffer beginning against magic-fallback-mode-alist.
2289    (unless done
2290      (if (setq done (save-excursion
2291		       (goto-char (point-min))
2292		       (save-restriction
2293			 (narrow-to-region (point-min)
2294					   (min (point-max)
2295						(+ (point-min) magic-mode-regexp-match-limit)))
2296			 (assoc-default nil magic-fallback-mode-alist
2297					(lambda (re dummy)
2298					  (if (functionp re)
2299					      (funcall re)
2300					    (looking-at re)))))))
2301	  (set-auto-mode-0 done keep-mode-if-same)))))
2302
2303;; When `keep-mode-if-same' is set, we are working on behalf of
2304;; set-visited-file-name.  In that case, if the major mode specified is the
2305;; same one we already have, don't actually reset it.  We don't want to lose
2306;; minor modes such as Font Lock.
2307(defun set-auto-mode-0 (mode &optional keep-mode-if-same)
2308  "Apply MODE and return it.
2309If optional arg KEEP-MODE-IF-SAME is non-nil, MODE is chased of
2310any aliases and compared to current major mode.  If they are the
2311same, do nothing and return nil."
2312  (unless (and keep-mode-if-same
2313	       (eq (indirect-function mode)
2314		   (indirect-function major-mode)))
2315    (when mode
2316      (funcall mode)
2317      mode)))
2318
2319(defun set-auto-mode-1 ()
2320  "Find the -*- spec in the buffer.
2321Call with point at the place to start searching from.
2322If one is found, set point to the beginning
2323and return the position of the end.
2324Otherwise, return nil; point may be changed."
2325  (let (beg end)
2326    (and
2327     ;; Don't look for -*- if this file name matches any
2328     ;; of the regexps in inhibit-first-line-modes-regexps.
2329     (let ((temp inhibit-first-line-modes-regexps)
2330	   (name (if buffer-file-name
2331		     (file-name-sans-versions buffer-file-name)
2332		   (buffer-name))))
2333       (while (let ((sufs inhibit-first-line-modes-suffixes))
2334		(while (and sufs (not (string-match (car sufs) name)))
2335		  (setq sufs (cdr sufs)))
2336		sufs)
2337	 (setq name (substring name 0 (match-beginning 0))))
2338       (while (and temp
2339		   (not (string-match (car temp) name)))
2340	 (setq temp (cdr temp)))
2341       (not temp))
2342
2343     (search-forward "-*-" (line-end-position
2344                            ;; If the file begins with "#!"
2345                            ;; (exec interpreter magic), look
2346                            ;; for mode frobs in the first two
2347                            ;; lines.  You cannot necessarily
2348                            ;; put them in the first line of
2349                            ;; such a file without screwing up
2350                            ;; the interpreter invocation.
2351                            (and (looking-at "^#!") 2)) t)
2352     (progn
2353       (skip-chars-forward " \t")
2354       (setq beg (point))
2355       (search-forward "-*-" (line-end-position) t))
2356     (progn
2357       (forward-char -3)
2358       (skip-chars-backward " \t")
2359       (setq end (point))
2360       (goto-char beg)
2361       end))))
2362
2363;;; Handling file local variables
2364
2365(defvar ignored-local-variables
2366  '(ignored-local-variables safe-local-variable-values)
2367  "Variables to be ignored in a file's local variable spec.")
2368
2369(defvar hack-local-variables-hook nil
2370  "Normal hook run after processing a file's local variables specs.
2371Major modes can use this to examine user-specified local variables
2372in order to initialize other data structure based on them.")
2373
2374(defcustom safe-local-variable-values nil
2375  "List variable-value pairs that are considered safe.
2376Each element is a cons cell (VAR . VAL), where VAR is a variable
2377symbol and VAL is a value that is considered safe."
2378  :group 'find-file
2379  :type  'alist)
2380
2381(defcustom safe-local-eval-forms nil
2382  "Expressions that are considered safe in an `eval:' local variable.
2383Add expressions to this list if you want Emacs to evaluate them, when
2384they appear in an `eval' local variable specification, without first
2385asking you for confirmation."
2386  :group 'find-file
2387  :version "22.1"
2388  :type '(repeat sexp))
2389
2390;; Risky local variables:
2391(mapc (lambda (var) (put var 'risky-local-variable t))
2392      '(after-load-alist
2393	auto-mode-alist
2394	buffer-auto-save-file-name
2395	buffer-file-name
2396	buffer-file-truename
2397	buffer-undo-list
2398	dabbrev-case-fold-search
2399	dabbrev-case-replace
2400	debugger
2401	default-text-properties
2402	display-time-string
2403	enable-local-eval
2404	enable-local-variables
2405	eval
2406	exec-directory
2407	exec-path
2408	file-name-handler-alist
2409	font-lock-defaults
2410	format-alist
2411	frame-title-format
2412	global-mode-string
2413	header-line-format
2414	icon-title-format
2415	ignored-local-variables
2416	imenu--index-alist
2417	imenu-generic-expression
2418	inhibit-quit
2419	input-method-alist
2420	load-path
2421	max-lisp-eval-depth
2422	max-specpdl-size
2423	minor-mode-alist
2424	minor-mode-map-alist
2425	minor-mode-overriding-map-alist
2426	mode-line-buffer-identification
2427	mode-line-format
2428	mode-line-modes
2429	mode-line-modified
2430	mode-line-mule-info
2431	mode-line-position
2432	mode-line-process
2433	mode-name
2434	outline-level
2435	overriding-local-map
2436	overriding-terminal-local-map
2437	parse-time-rules
2438	process-environment
2439	rmail-output-file-alist
2440	safe-local-variable-values
2441	safe-local-eval-forms
2442	save-some-buffers-action-alist
2443	special-display-buffer-names
2444	standard-input
2445	standard-output
2446	unread-command-events
2447	vc-mode))
2448
2449;; Safe local variables:
2450;;
2451;; For variables defined by major modes, the safety declarations can go into
2452;; the major mode's file, since that will be loaded before file variables are
2453;; processed.
2454;;
2455;; For variables defined by minor modes, put the safety declarations in the
2456;; file defining the minor mode after the defcustom/defvar using an autoload
2457;; cookie, e.g.:
2458;;
2459;;   ;;;###autoload(put 'variable 'safe-local-variable 'stringp)
2460;;
2461;; Otherwise, when Emacs visits a file specifying that local variable, the
2462;; minor mode file may not be loaded yet.
2463;;
2464;; For variables defined in the C source code the declaration should go here:
2465
2466(mapc (lambda (pair)
2467	(put (car pair) 'safe-local-variable (cdr pair)))
2468      '((buffer-read-only     . booleanp)   ;; C source code
2469	(default-directory    . stringp)    ;; C source code
2470	(fill-column          . integerp)   ;; C source code
2471	(indent-tabs-mode     . booleanp)   ;; C source code
2472	(left-margin          . integerp)   ;; C source code
2473	(no-update-autoloads  . booleanp)
2474	(tab-width            . integerp)   ;; C source code
2475	(truncate-lines       . booleanp))) ;; C source code
2476
2477(put 'c-set-style 'safe-local-eval-function t)
2478
2479(defun hack-local-variables-confirm (vars unsafe-vars risky-vars)
2480  (if noninteractive
2481      nil
2482    (let ((name (if buffer-file-name
2483		    (file-name-nondirectory buffer-file-name)
2484		  (concat "buffer " (buffer-name))))
2485	  (offer-save (and (eq enable-local-variables t) unsafe-vars))
2486	  prompt char)
2487      (save-window-excursion
2488	(let ((buf (get-buffer-create "*Local Variables*")))
2489	  (pop-to-buffer buf)
2490	  (set (make-local-variable 'cursor-type) nil)
2491	  (erase-buffer)
2492	  (if unsafe-vars
2493	      (insert "The local variables list in " name
2494		      "\ncontains values that may not be safe (*)"
2495		      (if risky-vars
2496			  ", and variables that are risky (**)."
2497			"."))
2498	    (if risky-vars
2499		(insert "The local variables list in " name
2500			"\ncontains variables that are risky (**).")
2501	      (insert "A local variables list is specified in " name ".")))
2502	  (insert "\n\nDo you want to apply it?  You can type
2503y  -- to apply the local variables list.
2504n  -- to ignore the local variables list.")
2505	  (if offer-save
2506	      (insert "
2507!  -- to apply the local variables list, and permanently mark these
2508      values (*) as safe (in the future, they will be set automatically.)\n\n")
2509	    (insert "\n\n"))
2510	  (dolist (elt vars)
2511	    (cond ((member elt unsafe-vars)
2512		   (insert "  * "))
2513		  ((member elt risky-vars)
2514		   (insert " ** "))
2515		  (t
2516		   (insert "    ")))
2517	    (princ (car elt) buf)
2518	    (insert " : ")
2519            ;; Make strings with embedded whitespace easier to read.
2520            (let ((print-escape-newlines t))
2521              (prin1 (cdr elt) buf))
2522	    (insert "\n"))
2523	  (setq prompt
2524		(format "Please type %s%s: "
2525			(if offer-save "y, n, or !" "y or n")
2526			(if (< (line-number-at-pos) (window-body-height))
2527			    ""
2528			  ", or C-v to scroll")))
2529	  (goto-char (point-min))
2530	  (let ((cursor-in-echo-area t)
2531		(executing-kbd-macro executing-kbd-macro)
2532		(exit-chars
2533		 (if offer-save '(?! ?y ?n ?\s ?\C-g) '(?y ?n ?\s ?\C-g)))
2534		done)
2535	    (while (not done)
2536	      (message prompt)
2537	      (setq char (read-event))
2538	      (if (numberp char)
2539		  (cond ((eq char ?\C-v)
2540			 (condition-case nil
2541			     (scroll-up)
2542			   (error (goto-char (point-min)))))
2543			;; read-event returns -1 if we are in a kbd
2544			;; macro and there are no more events in the
2545			;; macro.  In that case, attempt to get an
2546			;; event interactively.
2547			((and executing-kbd-macro (= char -1))
2548			 (setq executing-kbd-macro nil))
2549			(t (setq done (memq (downcase char) exit-chars)))))))
2550	  (setq char (downcase char))
2551	  (when (and offer-save (= char ?!) unsafe-vars)
2552	    (dolist (elt unsafe-vars)
2553	      (add-to-list 'safe-local-variable-values elt))
2554	    ;; When this is called from desktop-restore-file-buffer,
2555	    ;; coding-system-for-read may be non-nil.  Reset it before
2556	    ;; writing to .emacs.
2557	    (if (or custom-file user-init-file)
2558		(let ((coding-system-for-read nil))
2559		  (customize-save-variable
2560		   'safe-local-variable-values
2561		   safe-local-variable-values))))
2562	  (kill-buffer buf)
2563	  (or (= char ?!)
2564	      (= char ?\s)
2565	      (= char ?y)))))))
2566
2567(defun hack-local-variables-prop-line (&optional mode-only)
2568  "Return local variables specified in the -*- line.
2569Ignore any specification for `mode:' and `coding:';
2570`set-auto-mode' should already have handled `mode:',
2571`set-auto-coding' should already have handled `coding:'.
2572
2573If MODE-ONLY is non-nil, all we do is check whether the major
2574mode is specified, returning t if it is specified.  Otherwise,
2575return an alist of elements (VAR . VAL), where VAR is a variable
2576and VAL is the specified value."
2577  (save-excursion
2578    (goto-char (point-min))
2579    (let ((end (set-auto-mode-1))
2580	  result mode-specified)
2581      ;; Parse the -*- line into the RESULT alist.
2582      ;; Also set MODE-SPECIFIED if we see a spec or `mode'.
2583      (cond ((not end)
2584	     nil)
2585	    ((looking-at "[ \t]*\\([^ \t\n\r:;]+\\)\\([ \t]*-\\*-\\)")
2586	     ;; Simple form: "-*- MODENAME -*-".  Already handled.
2587	     (setq mode-specified t)
2588	     nil)
2589	    (t
2590	     ;; Hairy form: '-*-' [ <variable> ':' <value> ';' ]* '-*-'
2591	     ;; (last ";" is optional).
2592	     (while (< (point) end)
2593	       (or (looking-at "[ \t]*\\([^ \t\n:]+\\)[ \t]*:[ \t]*")
2594		   (error "Malformed -*- line"))
2595	       (goto-char (match-end 0))
2596	       ;; There used to be a downcase here,
2597	       ;; but the manual didn't say so,
2598	       ;; and people want to set var names that aren't all lc.
2599	       (let ((key (intern (match-string 1)))
2600		     (val (save-restriction
2601			    (narrow-to-region (point) end)
2602			    (read (current-buffer)))))
2603		 ;; It is traditional to ignore
2604		 ;; case when checking for `mode' in set-auto-mode,
2605		 ;; so we must do that here as well.
2606		 ;; That is inconsistent, but we're stuck with it.
2607		 ;; The same can be said for `coding' in set-auto-coding.
2608		 (or (and (equal (downcase (symbol-name key)) "mode")
2609			  (setq mode-specified t))
2610		     (equal (downcase (symbol-name key)) "coding")
2611		     (condition-case nil
2612			 (push (cons (if (eq key 'eval)
2613					 'eval
2614				       (indirect-variable key))
2615				     val) result)
2616		       (error nil)))
2617		 (skip-chars-forward " \t;")))))
2618
2619      (if mode-only
2620	  mode-specified
2621	result))))
2622
2623(defun hack-local-variables (&optional mode-only)
2624  "Parse and put into effect this buffer's local variables spec.
2625If MODE-ONLY is non-nil, all we do is check whether the major mode
2626is specified, returning t if it is specified."
2627  (let ((enable-local-variables
2628	 (and local-enable-local-variables enable-local-variables))
2629	result)
2630    (when (or mode-only enable-local-variables)
2631      (setq result (hack-local-variables-prop-line mode-only))
2632      ;; Look for "Local variables:" line in last page.
2633      (save-excursion
2634	(goto-char (point-max))
2635	(search-backward "\n\^L" (max (- (point-max) 3000) (point-min))
2636			 'move)
2637	(when (let ((case-fold-search t))
2638		(search-forward "Local Variables:" nil t))
2639	  (skip-chars-forward " \t")
2640	  ;; suffix is what comes after "local variables:" in its line.
2641	  ;; prefix is what comes before "local variables:" in its line.
2642	  (let ((suffix
2643		 (concat
2644		  (regexp-quote (buffer-substring (point)
2645						  (line-end-position)))
2646		  "$"))
2647		(prefix
2648		 (concat "^" (regexp-quote
2649			      (buffer-substring (line-beginning-position)
2650						(match-beginning 0)))))
2651		beg)
2652
2653	    (forward-line 1)
2654	    (let ((startpos (point))
2655		  endpos
2656		  (thisbuf (current-buffer)))
2657	      (save-excursion
2658		(unless (let ((case-fold-search t))
2659			  (re-search-forward
2660			   (concat prefix "[ \t]*End:[ \t]*" suffix)
2661			   nil t))
2662		  (error "Local variables list is not properly terminated"))
2663		(beginning-of-line)
2664		(setq endpos (point)))
2665
2666	      (with-temp-buffer
2667		(insert-buffer-substring thisbuf startpos endpos)
2668		(goto-char (point-min))
2669		(subst-char-in-region (point) (point-max) ?\^m ?\n)
2670		(while (not (eobp))
2671		  ;; Discard the prefix.
2672		  (if (looking-at prefix)
2673		      (delete-region (point) (match-end 0))
2674		    (error "Local variables entry is missing the prefix"))
2675		  (end-of-line)
2676		  ;; Discard the suffix.
2677		  (if (looking-back suffix)
2678		      (delete-region (match-beginning 0) (point))
2679		    (error "Local variables entry is missing the suffix"))
2680		  (forward-line 1))
2681		(goto-char (point-min))
2682
2683		(while (not (eobp))
2684		  ;; Find the variable name; strip whitespace.
2685		  (skip-chars-forward " \t")
2686		  (setq beg (point))
2687		  (skip-chars-forward "^:\n")
2688		  (if (eolp) (error "Missing colon in local variables entry"))
2689		  (skip-chars-backward " \t")
2690		  (let* ((str (buffer-substring beg (point)))
2691			 (var (read str))
2692			 val)
2693		    ;; Read the variable value.
2694		    (skip-chars-forward "^:")
2695		    (forward-char 1)
2696		    (setq val (read (current-buffer)))
2697		    (if mode-only
2698			(if (eq var 'mode)
2699			    (setq result t))
2700		      (unless (eq var 'coding)
2701			(condition-case nil
2702			    (push (cons (if (eq var 'eval)
2703					    'eval
2704					  (indirect-variable var))
2705					val) result)
2706			  (error nil)))))
2707		  (forward-line 1)))))))
2708
2709      ;; We've read all the local variables.  Now, return whether the
2710      ;; mode is specified (if MODE-ONLY is non-nil), or set the
2711      ;; variables (if MODE-ONLY is nil.)
2712      (if mode-only
2713	  result
2714	(dolist (ignored ignored-local-variables)
2715	  (setq result (assq-delete-all ignored result)))
2716	(if (null enable-local-eval)
2717	    (setq result (assq-delete-all 'eval result)))
2718	(when result
2719	  (setq result (nreverse result))
2720	  ;; Find those variables that we may want to save to
2721	  ;; `safe-local-variable-values'.
2722	  (let (risky-vars unsafe-vars)
2723	    (dolist (elt result)
2724	      (let ((var (car elt))
2725		    (val (cdr elt)))
2726		(or (eq var 'mode)
2727		    (and (eq var 'eval)
2728			 (or (eq enable-local-eval t)
2729			     (hack-one-local-variable-eval-safep
2730			      (eval (quote val)))))
2731		    (safe-local-variable-p var val)
2732		    (and (risky-local-variable-p var val)
2733			 (push elt risky-vars))
2734		    (push elt unsafe-vars))))
2735	    (if (eq enable-local-variables :safe)
2736		;; If caller wants only the safe variables,
2737		;; install only them.
2738		(dolist (elt result)
2739		  (unless (or (member elt unsafe-vars)
2740			      (member elt risky-vars))
2741		    (hack-one-local-variable (car elt) (cdr elt))))
2742	      ;; Query, except in the case where all are known safe
2743	      ;; if the user wants no quuery in that case.
2744	      (if (or (and (eq enable-local-variables t)
2745			   (null unsafe-vars)
2746			   (null risky-vars))
2747		      (eq enable-local-variables :all)
2748		      (hack-local-variables-confirm
2749		       result unsafe-vars risky-vars))
2750		  (dolist (elt result)
2751		    (hack-one-local-variable (car elt) (cdr elt)))))))
2752	(run-hooks 'hack-local-variables-hook)))))
2753
2754(defun safe-local-variable-p (sym val)
2755  "Non-nil if SYM is safe as a file-local variable with value VAL.
2756It is safe if any of these conditions are met:
2757
2758 * There is a matching entry (SYM . VAL) in the
2759   `safe-local-variable-values' user option.
2760
2761 * The `safe-local-variable' property of SYM is a function that
2762   evaluates to a non-nil value with VAL as an argument."
2763  (or (member (cons sym val) safe-local-variable-values)
2764      (let ((safep (get sym 'safe-local-variable)))
2765        (and (functionp safep) (funcall safep val)))))
2766
2767(defun risky-local-variable-p (sym &optional ignored)
2768  "Non-nil if SYM could be dangerous as a file-local variable.
2769It is dangerous if either of these conditions are met:
2770
2771 * Its `risky-local-variable' property is non-nil.
2772
2773 * Its name ends with \"hook(s)\", \"function(s)\", \"form(s)\", \"map\",
2774   \"program\", \"command(s)\", \"predicate(s)\", \"frame-alist\",
2775   \"mode-alist\", \"font-lock-(syntactic-)keyword*\",
2776   \"map-alist\", or \"bindat-spec\"."
2777  ;; If this is an alias, check the base name.
2778  (condition-case nil
2779      (setq sym (indirect-variable sym))
2780    (error nil))
2781  (or (get sym 'risky-local-variable)
2782      (string-match "-hooks?$\\|-functions?$\\|-forms?$\\|-program$\\|\
2783-commands?$\\|-predicates?$\\|font-lock-keywords$\\|font-lock-keywords\
2784-[0-9]+$\\|font-lock-syntactic-keywords$\\|-frame-alist$\\|-mode-alist$\\|\
2785-map$\\|-map-alist$\\|-bindat-spec$" (symbol-name sym))))
2786
2787(defun hack-one-local-variable-quotep (exp)
2788  (and (consp exp) (eq (car exp) 'quote) (consp (cdr exp))))
2789
2790(defun hack-one-local-variable-constantp (exp)
2791  (or (and (not (symbolp exp)) (not (consp exp)))
2792      (memq exp '(t nil))
2793      (keywordp exp)
2794      (hack-one-local-variable-quotep exp)))
2795
2796(defun hack-one-local-variable-eval-safep (exp)
2797  "Return t if it is safe to eval EXP when it is found in a file."
2798  (or (not (consp exp))
2799      ;; Detect certain `put' expressions.
2800      (and (eq (car exp) 'put)
2801	   (hack-one-local-variable-quotep (nth 1 exp))
2802	   (hack-one-local-variable-quotep (nth 2 exp))
2803	   (let ((prop (nth 1 (nth 2 exp))) (val (nth 3 exp)))
2804	     (cond ((eq prop 'lisp-indent-hook)
2805		    ;; Only allow safe values of lisp-indent-hook;
2806		    ;; not functions.
2807		    (or (numberp val) (equal val ''defun)))
2808		   ((eq prop 'edebug-form-spec)
2809		    ;; Only allow indirect form specs.
2810		    ;; During bootstrapping, edebug-basic-spec might not be
2811		    ;; defined yet.
2812                    (and (fboundp 'edebug-basic-spec)
2813			 (hack-one-local-variable-quotep val)
2814                         (edebug-basic-spec (nth 1 val)))))))
2815      ;; Allow expressions that the user requested.
2816      (member exp safe-local-eval-forms)
2817      ;; Certain functions can be allowed with safe arguments
2818      ;; or can specify verification functions to try.
2819      (and (symbolp (car exp))
2820	   (let ((prop (get (car exp) 'safe-local-eval-function)))
2821	     (cond ((eq prop t)
2822		    (let ((ok t))
2823		      (dolist (arg (cdr exp))
2824			(unless (hack-one-local-variable-constantp arg)
2825			  (setq ok nil)))
2826		      ok))
2827		   ((functionp prop)
2828		    (funcall prop exp))
2829		   ((listp prop)
2830		    (let ((ok nil))
2831		      (dolist (function prop)
2832			(if (funcall function exp)
2833			    (setq ok t)))
2834		      ok)))))))
2835
2836(defun hack-one-local-variable (var val)
2837  "Set local variable VAR with value VAL.
2838If VAR is `mode', call `VAL-mode' as a function unless it's
2839already the major mode."
2840  (cond ((eq var 'mode)
2841	 (let ((mode (intern (concat (downcase (symbol-name val))
2842				     "-mode"))))
2843	   (unless (eq (indirect-function mode)
2844		       (indirect-function major-mode))
2845	     (funcall mode))))
2846	((eq var 'eval)
2847	 (save-excursion (eval val)))
2848	(t
2849         ;; Make sure the string has no text properties.
2850         ;; Some text properties can get evaluated in various ways,
2851         ;; so it is risky to put them on with a local variable list.
2852         (if (stringp val)
2853             (set-text-properties 0 (length val) nil val))
2854         (set (make-local-variable var) val))))
2855
2856
2857(defcustom change-major-mode-with-file-name t
2858  "Non-nil means \\[write-file] should set the major mode from the file name.
2859However, the mode will not be changed if
2860\(1) a local variables list or the `-*-' line specifies a major mode, or
2861\(2) the current major mode is a \"special\" mode,
2862\     not suitable for ordinary files, or
2863\(3) the new file name does not particularly specify any mode."
2864  :type 'boolean
2865  :group 'editing-basics)
2866
2867(defun set-visited-file-name (filename &optional no-query along-with-file)
2868  "Change name of file visited in current buffer to FILENAME.
2869This also renames the buffer to correspond to the new file.
2870The next time the buffer is saved it will go in the newly specified file.
2871FILENAME nil or an empty string means mark buffer as not visiting any file.
2872Remember to delete the initial contents of the minibuffer
2873if you wish to pass an empty string as the argument.
2874
2875The optional second argument NO-QUERY, if non-nil, inhibits asking for
2876confirmation in the case where another buffer is already visiting FILENAME.
2877
2878The optional third argument ALONG-WITH-FILE, if non-nil, means that
2879the old visited file has been renamed to the new name FILENAME."
2880  (interactive "FSet visited file name: ")
2881  (if (buffer-base-buffer)
2882      (error "An indirect buffer cannot visit a file"))
2883  (let (truename)
2884    (if filename
2885	(setq filename
2886	      (if (string-equal filename "")
2887		  nil
2888		(expand-file-name filename))))
2889    (if filename
2890	(progn
2891	  (setq truename (file-truename filename))
2892	  (if find-file-visit-truename
2893	      (setq filename truename))))
2894    (if filename
2895	(let ((new-name (file-name-nondirectory filename)))
2896	  (if (string= new-name "")
2897	      (error "Empty file name"))))
2898    (let ((buffer (and filename (find-buffer-visiting filename))))
2899      (and buffer (not (eq buffer (current-buffer)))
2900	   (not no-query)
2901	   (not (y-or-n-p (format "A buffer is visiting %s; proceed? "
2902                                  filename)))
2903	   (error "Aborted")))
2904    (or (equal filename buffer-file-name)
2905	(progn
2906	  (and filename (lock-buffer filename))
2907	  (unlock-buffer)))
2908    (setq buffer-file-name filename)
2909    (if filename			; make buffer name reflect filename.
2910	(let ((new-name (file-name-nondirectory buffer-file-name)))
2911	  (if (eq system-type 'vax-vms)
2912	      (setq new-name (downcase new-name)))
2913	  (setq default-directory (file-name-directory buffer-file-name))
2914	  ;; If new-name == old-name, renaming would add a spurious <2>
2915	  ;; and it's considered as a feature in rename-buffer.
2916	  (or (string= new-name (buffer-name))
2917	      (rename-buffer new-name t))))
2918    (setq buffer-backed-up nil)
2919    (or along-with-file
2920	(clear-visited-file-modtime))
2921    ;; Abbreviate the file names of the buffer.
2922    (if truename
2923	(progn
2924	  (setq buffer-file-truename (abbreviate-file-name truename))
2925	  (if find-file-visit-truename
2926	      (setq buffer-file-name truename))))
2927    (setq buffer-file-number
2928	  (if filename
2929	      (nthcdr 10 (file-attributes buffer-file-name))
2930	      nil)))
2931  ;; write-file-functions is normally used for things like ftp-find-file
2932  ;; that visit things that are not local files as if they were files.
2933  ;; Changing to visit an ordinary local file instead should flush the hook.
2934  (kill-local-variable 'write-file-functions)
2935  (kill-local-variable 'local-write-file-hooks)
2936  (kill-local-variable 'revert-buffer-function)
2937  (kill-local-variable 'backup-inhibited)
2938  ;; If buffer was read-only because of version control,
2939  ;; that reason is gone now, so make it writable.
2940  (if vc-mode
2941      (setq buffer-read-only nil))
2942  (kill-local-variable 'vc-mode)
2943  ;; Turn off backup files for certain file names.
2944  ;; Since this is a permanent local, the major mode won't eliminate it.
2945  (and buffer-file-name
2946       backup-enable-predicate
2947       (not (funcall backup-enable-predicate buffer-file-name))
2948       (progn
2949	 (make-local-variable 'backup-inhibited)
2950	 (setq backup-inhibited t)))
2951  (let ((oauto buffer-auto-save-file-name))
2952    ;; If auto-save was not already on, turn it on if appropriate.
2953    (if (not buffer-auto-save-file-name)
2954	(and buffer-file-name auto-save-default
2955	     (auto-save-mode t))
2956      ;; If auto save is on, start using a new name.
2957      ;; We deliberately don't rename or delete the old auto save
2958      ;; for the old visited file name.  This is because perhaps
2959      ;; the user wants to save the new state and then compare with the
2960      ;; previous state from the auto save file.
2961      (setq buffer-auto-save-file-name
2962	    (make-auto-save-file-name)))
2963    ;; Rename the old auto save file if any.
2964    (and oauto buffer-auto-save-file-name
2965	 (file-exists-p oauto)
2966	 (rename-file oauto buffer-auto-save-file-name t)))
2967  (and buffer-file-name
2968       (not along-with-file)
2969       (set-buffer-modified-p t))
2970  ;; Update the major mode, if the file name determines it.
2971  (condition-case nil
2972      ;; Don't change the mode if it is special.
2973      (or (not change-major-mode-with-file-name)
2974	  (get major-mode 'mode-class)
2975	  ;; Don't change the mode if the local variable list specifies it.
2976	  (hack-local-variables t)
2977	  (set-auto-mode t))
2978    (error nil)))
2979
2980(defun write-file (filename &optional confirm)
2981  "Write current buffer into file FILENAME.
2982This makes the buffer visit that file, and marks it as not modified.
2983
2984If you specify just a directory name as FILENAME, that means to use
2985the default file name but in that directory.  You can also yank
2986the default file name into the minibuffer to edit it, using \\<minibuffer-local-map>\\[next-history-element].
2987
2988If the buffer is not already visiting a file, the default file name
2989for the output file is the buffer name.
2990
2991If optional second arg CONFIRM is non-nil, this function
2992asks for confirmation before overwriting an existing file.
2993Interactively, confirmation is required unless you supply a prefix argument."
2994;;  (interactive "FWrite file: ")
2995  (interactive
2996   (list (if buffer-file-name
2997	     (read-file-name "Write file: "
2998			     nil nil nil nil)
2999	   (read-file-name "Write file: " default-directory
3000			   (expand-file-name
3001			    (file-name-nondirectory (buffer-name))
3002			    default-directory)
3003			   nil nil))
3004	 (not current-prefix-arg)))
3005  (or (null filename) (string-equal filename "")
3006      (progn
3007	;; If arg is just a directory,
3008	;; use the default file name, but in that directory.
3009	(if (file-directory-p filename)
3010	    (setq filename (concat (file-name-as-directory filename)
3011				   (file-name-nondirectory
3012				    (or buffer-file-name (buffer-name))))))
3013	(and confirm
3014	     (file-exists-p filename)
3015	     (or (y-or-n-p (format "File `%s' exists; overwrite? " filename))
3016		 (error "Canceled")))
3017	(set-visited-file-name filename (not confirm))))
3018  (set-buffer-modified-p t)
3019  ;; Make buffer writable if file is writable.
3020  (and buffer-file-name
3021       (file-writable-p buffer-file-name)
3022       (setq buffer-read-only nil))
3023  (save-buffer)
3024  ;; It's likely that the VC status at the new location is different from
3025  ;; the one at the old location.
3026  (vc-find-file-hook))
3027
3028(defun backup-buffer ()
3029  "Make a backup of the disk file visited by the current buffer, if appropriate.
3030This is normally done before saving the buffer the first time.
3031
3032A backup may be done by renaming or by copying; see documentation of
3033variable `make-backup-files'.  If it's done by renaming, then the file is
3034no longer accessible under its old name.
3035
3036The value is non-nil after a backup was made by renaming.
3037It has the form (MODES . BACKUPNAME).
3038MODES is the result of `file-modes' on the original
3039file; this means that the caller, after saving the buffer, should change
3040the modes of the new file to agree with the old modes.
3041BACKUPNAME is the backup file name, which is the old file renamed."
3042  (if (and make-backup-files (not backup-inhibited)
3043	   (not buffer-backed-up)
3044	   (file-exists-p buffer-file-name)
3045	   (memq (aref (elt (file-attributes buffer-file-name) 8) 0)
3046		 '(?- ?l)))
3047      (let ((real-file-name buffer-file-name)
3048	    backup-info backupname targets setmodes)
3049	;; If specified name is a symbolic link, chase it to the target.
3050	;; Thus we make the backups in the directory where the real file is.
3051	(setq real-file-name (file-chase-links real-file-name))
3052	(setq backup-info (find-backup-file-name real-file-name)
3053	      backupname (car backup-info)
3054	      targets (cdr backup-info))
3055	;; (if (file-directory-p buffer-file-name)
3056	;;     (error "Cannot save buffer in directory %s" buffer-file-name))
3057	(if backup-info
3058	    (condition-case ()
3059		(let ((delete-old-versions
3060		       ;; If have old versions to maybe delete,
3061		       ;; ask the user to confirm now, before doing anything.
3062		       ;; But don't actually delete til later.
3063		       (and targets
3064			    (or (eq delete-old-versions t) (eq delete-old-versions nil))
3065			    (or delete-old-versions
3066				(y-or-n-p (format "Delete excess backup versions of %s? "
3067						  real-file-name)))))
3068		      (modes (file-modes buffer-file-name)))
3069		  ;; Actually write the back up file.
3070		  (condition-case ()
3071		      (if (or file-precious-flag
3072    ;			      (file-symlink-p buffer-file-name)
3073			      backup-by-copying
3074			      ;; Don't rename a suid or sgid file.
3075			      (and modes (< 0 (logand modes #o6000)))
3076			      (not (file-writable-p (file-name-directory real-file-name)))
3077			      (and backup-by-copying-when-linked
3078				   (> (file-nlinks real-file-name) 1))
3079			      (and (or backup-by-copying-when-mismatch
3080				       (integerp backup-by-copying-when-privileged-mismatch))
3081				   (let ((attr (file-attributes real-file-name)))
3082				     (and (or backup-by-copying-when-mismatch
3083					      (and (integerp (nth 2 attr))
3084						   (integerp backup-by-copying-when-privileged-mismatch)
3085						   (<= (nth 2 attr) backup-by-copying-when-privileged-mismatch)))
3086					  (or (nth 9 attr)
3087					      (not (file-ownership-preserved-p real-file-name)))))))
3088			  (backup-buffer-copy real-file-name backupname modes)
3089			;; rename-file should delete old backup.
3090			(rename-file real-file-name backupname t)
3091			(setq setmodes (cons modes backupname)))
3092		    (file-error
3093		     ;; If trouble writing the backup, write it in ~.
3094		     (setq backupname (expand-file-name
3095				       (convert-standard-filename
3096					"~/%backup%~")))
3097		     (message "Cannot write backup file; backing up in %s"
3098			      backupname)
3099		     (sleep-for 1)
3100		     (backup-buffer-copy real-file-name backupname modes)))
3101		  (setq buffer-backed-up t)
3102		  ;; Now delete the old versions, if desired.
3103		  (if delete-old-versions
3104		      (while targets
3105			(condition-case ()
3106			    (delete-file (car targets))
3107			  (file-error nil))
3108			(setq targets (cdr targets))))
3109		  setmodes)
3110	    (file-error nil))))))
3111
3112(defun backup-buffer-copy (from-name to-name modes)
3113  (let ((umask (default-file-modes)))
3114    (unwind-protect
3115	(progn
3116	  ;; Create temp files with strict access rights.  It's easy to
3117	  ;; loosen them later, whereas it's impossible to close the
3118	  ;; time-window of loose permissions otherwise.
3119	  (set-default-file-modes ?\700)
3120	  (while (condition-case ()
3121		     (progn
3122		       (condition-case nil
3123			   (delete-file to-name)
3124			 (file-error nil))
3125		       (copy-file from-name to-name nil t)
3126		       nil)
3127		   (file-already-exists t))
3128	    ;; The file was somehow created by someone else between
3129	    ;; `delete-file' and `copy-file', so let's try again.
3130	    nil))
3131      ;; Reset the umask.
3132      (set-default-file-modes umask)))
3133  (and modes
3134       (set-file-modes to-name (logand modes #o1777))))
3135
3136(defun file-name-sans-versions (name &optional keep-backup-version)
3137  "Return file NAME sans backup versions or strings.
3138This is a separate procedure so your site-init or startup file can
3139redefine it.
3140If the optional argument KEEP-BACKUP-VERSION is non-nil,
3141we do not remove backup version numbers, only true file version numbers."
3142  (let ((handler (find-file-name-handler name 'file-name-sans-versions)))
3143    (if handler
3144	(funcall handler 'file-name-sans-versions name keep-backup-version)
3145      (substring name 0
3146		 (if (eq system-type 'vax-vms)
3147		     ;; VMS version number is (a) semicolon, optional
3148		     ;; sign, zero or more digits or (b) period, option
3149		     ;; sign, zero or more digits, provided this is the
3150		     ;; second period encountered outside of the
3151		     ;; device/directory part of the file name.
3152		     (or (string-match ";[-+]?[0-9]*\\'" name)
3153			 (if (string-match "\\.[^]>:]*\\(\\.[-+]?[0-9]*\\)\\'"
3154					   name)
3155			     (match-beginning 1))
3156			 (length name))
3157		   (if keep-backup-version
3158		       (length name)
3159		     (or (string-match "\\.~[0-9.]+~\\'" name)
3160			 (string-match "~\\'" name)
3161			 (length name))))))))
3162
3163(defun file-ownership-preserved-p (file)
3164  "Return t if deleting FILE and rewriting it would preserve the owner."
3165  (let ((handler (find-file-name-handler file 'file-ownership-preserved-p)))
3166    (if handler
3167	(funcall handler 'file-ownership-preserved-p file)
3168      (let ((attributes (file-attributes file)))
3169	;; Return t if the file doesn't exist, since it's true that no
3170	;; information would be lost by an (attempted) delete and create.
3171	(or (null attributes)
3172	    (= (nth 2 attributes) (user-uid)))))))
3173
3174(defun file-name-sans-extension (filename)
3175  "Return FILENAME sans final \"extension\".
3176The extension, in a file name, is the part that follows the last `.',
3177except that a leading `.', if any, doesn't count."
3178  (save-match-data
3179    (let ((file (file-name-sans-versions (file-name-nondirectory filename)))
3180	  directory)
3181      (if (and (string-match "\\.[^.]*\\'" file)
3182	       (not (eq 0 (match-beginning 0))))
3183	  (if (setq directory (file-name-directory filename))
3184	      ;; Don't use expand-file-name here; if DIRECTORY is relative,
3185	      ;; we don't want to expand it.
3186	      (concat directory (substring file 0 (match-beginning 0)))
3187	    (substring file 0 (match-beginning 0)))
3188	filename))))
3189
3190(defun file-name-extension (filename &optional period)
3191  "Return FILENAME's final \"extension\".
3192The extension, in a file name, is the part that follows the last `.',
3193excluding version numbers and backup suffixes,
3194except that a leading `.', if any, doesn't count.
3195Return nil for extensionless file names such as `foo'.
3196Return the empty string for file names such as `foo.'.
3197
3198If PERIOD is non-nil, then the returned value includes the period
3199that delimits the extension, and if FILENAME has no extension,
3200the value is \"\"."
3201  (save-match-data
3202    (let ((file (file-name-sans-versions (file-name-nondirectory filename))))
3203      (if (and (string-match "\\.[^.]*\\'" file)
3204	       (not (eq 0 (match-beginning 0))))
3205          (substring file (+ (match-beginning 0) (if period 0 1)))
3206        (if period
3207            "")))))
3208
3209(defcustom make-backup-file-name-function nil
3210  "A function to use instead of the default `make-backup-file-name'.
3211A value of nil gives the default `make-backup-file-name' behavior.
3212
3213This could be buffer-local to do something special for specific
3214files.  If you define it, you may need to change `backup-file-name-p'
3215and `file-name-sans-versions' too.
3216
3217See also `backup-directory-alist'."
3218  :group 'backup
3219  :type '(choice (const :tag "Default" nil)
3220		 (function :tag "Your function")))
3221
3222(defcustom backup-directory-alist nil
3223  "Alist of filename patterns and backup directory names.
3224Each element looks like (REGEXP . DIRECTORY).  Backups of files with
3225names matching REGEXP will be made in DIRECTORY.  DIRECTORY may be
3226relative or absolute.  If it is absolute, so that all matching files
3227are backed up into the same directory, the file names in this
3228directory will be the full name of the file backed up with all
3229directory separators changed to `!' to prevent clashes.  This will not
3230work correctly if your filesystem truncates the resulting name.
3231
3232For the common case of all backups going into one directory, the alist
3233should contain a single element pairing \".\" with the appropriate
3234directory name.
3235
3236If this variable is nil, or it fails to match a filename, the backup
3237is made in the original file's directory.
3238
3239On MS-DOS filesystems without long names this variable is always
3240ignored."
3241  :group 'backup
3242  :type '(repeat (cons (regexp :tag "Regexp matching filename")
3243		       (directory :tag "Backup directory name"))))
3244
3245(defun normal-backup-enable-predicate (name)
3246  "Default `backup-enable-predicate' function.
3247Checks for files in `temporary-file-directory',
3248`small-temporary-file-directory', and /tmp."
3249  (not (or (let ((comp (compare-strings temporary-file-directory 0 nil
3250					name 0 nil)))
3251	     ;; Directory is under temporary-file-directory.
3252	     (and (not (eq comp t))
3253		  (< comp (- (length temporary-file-directory)))))
3254	   (let ((comp (compare-strings "/tmp" 0 nil
3255					name 0 nil)))
3256	     ;; Directory is under /tmp.
3257	     (and (not (eq comp t))
3258		  (< comp (- (length "/tmp")))))
3259	   (if small-temporary-file-directory
3260	       (let ((comp (compare-strings small-temporary-file-directory
3261					    0 nil
3262					    name 0 nil)))
3263		 ;; Directory is under small-temporary-file-directory.
3264		 (and (not (eq comp t))
3265		      (< comp (- (length small-temporary-file-directory)))))))))
3266
3267(defun make-backup-file-name (file)
3268  "Create the non-numeric backup file name for FILE.
3269Normally this will just be the file's name with `~' appended.
3270Customization hooks are provided as follows.
3271
3272If the variable `make-backup-file-name-function' is non-nil, its value
3273should be a function which will be called with FILE as its argument;
3274the resulting name is used.
3275
3276Otherwise a match for FILE is sought in `backup-directory-alist'; see
3277the documentation of that variable.  If the directory for the backup
3278doesn't exist, it is created."
3279  (if make-backup-file-name-function
3280      (funcall make-backup-file-name-function file)
3281    (if (and (eq system-type 'ms-dos)
3282	     (not (msdos-long-file-names)))
3283	(let ((fn (file-name-nondirectory file)))
3284	  (concat (file-name-directory file)
3285		  (or (and (string-match "\\`[^.]+\\'" fn)
3286			   (concat (match-string 0 fn) ".~"))
3287		      (and (string-match "\\`[^.]+\\.\\(..?\\)?" fn)
3288			   (concat (match-string 0 fn) "~")))))
3289      (concat (make-backup-file-name-1 file) "~"))))
3290
3291(defun make-backup-file-name-1 (file)
3292  "Subroutine of `make-backup-file-name' and `find-backup-file-name'."
3293  (let ((alist backup-directory-alist)
3294	elt backup-directory abs-backup-directory)
3295    (while alist
3296      (setq elt (pop alist))
3297      (if (string-match (car elt) file)
3298	  (setq backup-directory (cdr elt)
3299		alist nil)))
3300    ;; If backup-directory is relative, it should be relative to the
3301    ;; file's directory.  By expanding explicitly here, we avoid
3302    ;; depending on default-directory.
3303    (if backup-directory
3304	(setq abs-backup-directory
3305	      (expand-file-name backup-directory
3306				(file-name-directory file))))
3307    (if (and abs-backup-directory (not (file-exists-p abs-backup-directory)))
3308	(condition-case nil
3309	    (make-directory abs-backup-directory 'parents)
3310	  (file-error (setq backup-directory nil
3311			    abs-backup-directory nil))))
3312    (if (null backup-directory)
3313	file
3314      (if (file-name-absolute-p backup-directory)
3315	  (progn
3316	    (when (memq system-type '(windows-nt ms-dos cygwin))
3317	      ;; Normalize DOSish file names: downcase the drive
3318	      ;; letter, if any, and replace the leading "x:" with
3319	      ;; "/drive_x".
3320	      (or (file-name-absolute-p file)
3321		  (setq file (expand-file-name file))) ; make defaults explicit
3322	      ;; Replace any invalid file-name characters (for the
3323	      ;; case of backing up remote files).
3324	      (setq file (expand-file-name (convert-standard-filename file)))
3325	      (if (eq (aref file 1) ?:)
3326		  (setq file (concat "/"
3327				     "drive_"
3328				     (char-to-string (downcase (aref file 0)))
3329				     (if (eq (aref file 2) ?/)
3330					 ""
3331				       "/")
3332				     (substring file 2)))))
3333	    ;; Make the name unique by substituting directory
3334	    ;; separators.  It may not really be worth bothering about
3335	    ;; doubling `!'s in the original name...
3336	    (expand-file-name
3337	     (subst-char-in-string
3338	      ?/ ?!
3339	      (replace-regexp-in-string "!" "!!" file))
3340	     backup-directory))
3341	(expand-file-name (file-name-nondirectory file)
3342			  (file-name-as-directory abs-backup-directory))))))
3343
3344(defun backup-file-name-p (file)
3345  "Return non-nil if FILE is a backup file name (numeric or not).
3346This is a separate function so you can redefine it for customization.
3347You may need to redefine `file-name-sans-versions' as well."
3348    (string-match "~\\'" file))
3349
3350(defvar backup-extract-version-start)
3351
3352;; This is used in various files.
3353;; The usage of backup-extract-version-start is not very clean,
3354;; but I can't see a good alternative, so as of now I am leaving it alone.
3355(defun backup-extract-version (fn)
3356  "Given the name of a numeric backup file, FN, return the backup number.
3357Uses the free variable `backup-extract-version-start', whose value should be
3358the index in the name where the version number begins."
3359  (if (and (string-match "[0-9]+~$" fn backup-extract-version-start)
3360	   (= (match-beginning 0) backup-extract-version-start))
3361      (string-to-number (substring fn backup-extract-version-start -1))
3362      0))
3363
3364;; I believe there is no need to alter this behavior for VMS;
3365;; since backup files are not made on VMS, it should not get called.
3366(defun find-backup-file-name (fn)
3367  "Find a file name for a backup file FN, and suggestions for deletions.
3368Value is a list whose car is the name for the backup file
3369and whose cdr is a list of old versions to consider deleting now.
3370If the value is nil, don't make a backup.
3371Uses `backup-directory-alist' in the same way as does
3372`make-backup-file-name'."
3373  (let ((handler (find-file-name-handler fn 'find-backup-file-name)))
3374    ;; Run a handler for this function so that ange-ftp can refuse to do it.
3375    (if handler
3376	(funcall handler 'find-backup-file-name fn)
3377      (if (or (eq version-control 'never)
3378	      ;; We don't support numbered backups on plain MS-DOS
3379	      ;; when long file names are unavailable.
3380	      (and (eq system-type 'ms-dos)
3381		   (not (msdos-long-file-names))))
3382	  (list (make-backup-file-name fn))
3383	(let* ((basic-name (make-backup-file-name-1 fn))
3384	       (base-versions (concat (file-name-nondirectory basic-name)
3385				      ".~"))
3386	       (backup-extract-version-start (length base-versions))
3387	       (high-water-mark 0)
3388	       (number-to-delete 0)
3389	       possibilities deserve-versions-p versions)
3390	  (condition-case ()
3391	      (setq possibilities (file-name-all-completions
3392				   base-versions
3393				   (file-name-directory basic-name))
3394		    versions (sort (mapcar #'backup-extract-version
3395					   possibilities)
3396				   #'<)
3397		    high-water-mark (apply 'max 0 versions)
3398		    deserve-versions-p (or version-control
3399					   (> high-water-mark 0))
3400		    number-to-delete (- (length versions)
3401					kept-old-versions
3402					kept-new-versions
3403					-1))
3404	    (file-error (setq possibilities nil)))
3405	  (if (not deserve-versions-p)
3406	      (list (make-backup-file-name fn))
3407	    (cons (format "%s.~%d~" basic-name (1+ high-water-mark))
3408		  (if (and (> number-to-delete 0)
3409			   ;; Delete nothing if there is overflow
3410			   ;; in the number of versions to keep.
3411			   (>= (+ kept-new-versions kept-old-versions -1) 0))
3412		      (mapcar (lambda (n)
3413				(format "%s.~%d~" basic-name n))
3414			      (let ((v (nthcdr kept-old-versions versions)))
3415				(rplacd (nthcdr (1- number-to-delete) v) ())
3416				v))))))))))
3417
3418(defun file-nlinks (filename)
3419  "Return number of names file FILENAME has."
3420  (car (cdr (file-attributes filename))))
3421
3422;; (defun file-relative-name (filename &optional directory)
3423;;   "Convert FILENAME to be relative to DIRECTORY (default: `default-directory').
3424;; This function returns a relative file name which is equivalent to FILENAME
3425;; when used with that default directory as the default.
3426;; If this is impossible (which can happen on MSDOS and Windows
3427;; when the file name and directory use different drive names)
3428;; then it returns FILENAME."
3429;;   (save-match-data
3430;;     (let ((fname (expand-file-name filename)))
3431;;       (setq directory (file-name-as-directory
3432;; 		       (expand-file-name (or directory default-directory))))
3433;;       ;; On Microsoft OSes, if FILENAME and DIRECTORY have different
3434;;       ;; drive names, they can't be relative, so return the absolute name.
3435;;       (if (and (or (eq system-type 'ms-dos)
3436;; 		   (eq system-type 'cygwin)
3437;; 		   (eq system-type 'windows-nt))
3438;; 	       (not (string-equal (substring fname  0 2)
3439;; 				  (substring directory 0 2))))
3440;; 	  filename
3441;; 	(let ((ancestor ".")
3442;; 	      (fname-dir (file-name-as-directory fname)))
3443;; 	  (while (and (not (string-match (concat "^" (regexp-quote directory)) fname-dir))
3444;; 		      (not (string-match (concat "^" (regexp-quote directory)) fname)))
3445;; 	    (setq directory (file-name-directory (substring directory 0 -1))
3446;; 		  ancestor (if (equal ancestor ".")
3447;; 			       ".."
3448;; 			     (concat "../" ancestor))))
3449;; 	  ;; Now ancestor is empty, or .., or ../.., etc.
3450;; 	  (if (string-match (concat "^" (regexp-quote directory)) fname)
3451;; 	      ;; We matched within FNAME's directory part.
3452;; 	      ;; Add the rest of FNAME onto ANCESTOR.
3453;; 	      (let ((rest (substring fname (match-end 0))))
3454;; 		(if (and (equal ancestor ".")
3455;; 			 (not (equal rest "")))
3456;; 		    ;; But don't bother with ANCESTOR if it would give us `./'.
3457;; 		    rest
3458;; 		  (concat (file-name-as-directory ancestor) rest)))
3459;; 	    ;; We matched FNAME's directory equivalent.
3460;; 	    ancestor))))))
3461
3462(defun file-relative-name (filename &optional directory)
3463  "Convert FILENAME to be relative to DIRECTORY (default: `default-directory').
3464This function returns a relative file name which is equivalent to FILENAME
3465when used with that default directory as the default.
3466If FILENAME and DIRECTORY lie on different machines or on different drives
3467on a DOS/Windows machine, it returns FILENAME in expanded form."
3468  (save-match-data
3469    (setq directory
3470	  (file-name-as-directory (expand-file-name (or directory
3471							default-directory))))
3472    (setq filename (expand-file-name filename))
3473    (let ((fremote (file-remote-p filename))
3474          (dremote (file-remote-p directory)))
3475      (if ;; Conditions for separate trees
3476	  (or
3477	   ;; Test for different drives on DOS/Windows
3478	   (and
3479	    ;; Should `cygwin' really be included here?  --stef
3480	    (memq system-type '(ms-dos cygwin windows-nt))
3481	    (not (eq t (compare-strings filename 0 2 directory 0 2))))
3482	   ;; Test for different remote file system identification
3483	   (not (equal fremote dremote)))
3484	  filename
3485        (let ((ancestor ".")
3486	      (filename-dir (file-name-as-directory filename)))
3487          (while (not
3488		  (or
3489		   (eq t (compare-strings filename-dir nil (length directory)
3490					  directory nil nil case-fold-search))
3491		   (eq t (compare-strings filename nil (length directory)
3492					  directory nil nil case-fold-search))))
3493            (setq directory (file-name-directory (substring directory 0 -1))
3494		  ancestor (if (equal ancestor ".")
3495			       ".."
3496			     (concat "../" ancestor))))
3497          ;; Now ancestor is empty, or .., or ../.., etc.
3498          (if (eq t (compare-strings filename nil (length directory)
3499				     directory nil nil case-fold-search))
3500	      ;; We matched within FILENAME's directory part.
3501	      ;; Add the rest of FILENAME onto ANCESTOR.
3502	      (let ((rest (substring filename (length directory))))
3503		(if (and (equal ancestor ".") (not (equal rest "")))
3504		    ;; But don't bother with ANCESTOR if it would give us `./'.
3505		    rest
3506		  (concat (file-name-as-directory ancestor) rest)))
3507            ;; We matched FILENAME's directory equivalent.
3508            ancestor))))))
3509
3510(defun save-buffer (&optional args)
3511  "Save current buffer in visited file if modified.
3512Variations are described below.
3513
3514By default, makes the previous version into a backup file
3515 if previously requested or if this is the first save.
3516Prefixed with one \\[universal-argument], marks this version
3517 to become a backup when the next save is done.
3518Prefixed with two \\[universal-argument]'s,
3519 unconditionally makes the previous version into a backup file.
3520Prefixed with three \\[universal-argument]'s, marks this version
3521 to become a backup when the next save is done,
3522 and unconditionally makes the previous version into a backup file.
3523
3524With a numeric argument of 0, never make the previous version
3525into a backup file.
3526
3527If a file's name is FOO, the names of its numbered backup versions are
3528 FOO.~i~ for various integers i.  A non-numbered backup file is called FOO~.
3529Numeric backups (rather than FOO~) will be made if value of
3530 `version-control' is not the atom `never' and either there are already
3531 numeric versions of the file being backed up, or `version-control' is
3532 non-nil.
3533We don't want excessive versions piling up, so there are variables
3534 `kept-old-versions', which tells Emacs how many oldest versions to keep,
3535 and `kept-new-versions', which tells how many newest versions to keep.
3536 Defaults are 2 old versions and 2 new.
3537`dired-kept-versions' controls dired's clean-directory (.) command.
3538If `delete-old-versions' is nil, system will query user
3539 before trimming versions.  Otherwise it does it silently.
3540
3541If `vc-make-backup-files' is nil, which is the default,
3542 no backup files are made for files managed by version control.
3543 (This is because the version control system itself records previous versions.)
3544
3545See the subroutine `basic-save-buffer' for more information."
3546  (interactive "p")
3547  (let ((modp (buffer-modified-p))
3548	(large (> (buffer-size) 50000))
3549	(make-backup-files (or (and make-backup-files (not (eq args 0)))
3550			       (memq args '(16 64)))))
3551    (and modp (memq args '(16 64)) (setq buffer-backed-up nil))
3552    (if (and modp large (buffer-file-name))
3553	(message "Saving file %s..." (buffer-file-name)))
3554    (basic-save-buffer)
3555    (and modp (memq args '(4 64)) (setq buffer-backed-up nil))))
3556
3557(defun delete-auto-save-file-if-necessary (&optional force)
3558  "Delete auto-save file for current buffer if `delete-auto-save-files' is t.
3559Normally delete only if the file was written by this Emacs since
3560the last real save, but optional arg FORCE non-nil means delete anyway."
3561  (and buffer-auto-save-file-name delete-auto-save-files
3562       (not (string= buffer-file-name buffer-auto-save-file-name))
3563       (or force (recent-auto-save-p))
3564       (progn
3565	 (condition-case ()
3566	     (delete-file buffer-auto-save-file-name)
3567	   (file-error nil))
3568	 (set-buffer-auto-saved))))
3569
3570(defvar auto-save-hook nil
3571  "Normal hook run just before auto-saving.")
3572
3573(defcustom before-save-hook nil
3574  "Normal hook that is run before a buffer is saved to its file."
3575  :options '(copyright-update time-stamp)
3576  :type 'hook
3577  :group 'files)
3578
3579(defcustom after-save-hook nil
3580  "Normal hook that is run after a buffer is saved to its file."
3581  :options '(executable-make-buffer-file-executable-if-script-p)
3582  :type 'hook
3583  :group 'files)
3584
3585(defvar save-buffer-coding-system nil
3586  "If non-nil, use this coding system for saving the buffer.
3587More precisely, use this coding system in place of the
3588value of `buffer-file-coding-system', when saving the buffer.
3589Calling `write-region' for any purpose other than saving the buffer
3590will still use `buffer-file-coding-system'; this variable has no effect
3591in such cases.")
3592
3593(make-variable-buffer-local 'save-buffer-coding-system)
3594(put 'save-buffer-coding-system 'permanent-local t)
3595
3596(defun basic-save-buffer ()
3597  "Save the current buffer in its visited file, if it has been modified.
3598The hooks `write-contents-functions' and `write-file-functions' get a chance
3599to do the job of saving; if they do not, then the buffer is saved in
3600the visited file in the usual way.
3601Before and after saving the buffer, this function runs
3602`before-save-hook' and `after-save-hook', respectively."
3603  (interactive)
3604  (save-current-buffer
3605    ;; In an indirect buffer, save its base buffer instead.
3606    (if (buffer-base-buffer)
3607	(set-buffer (buffer-base-buffer)))
3608    (if (buffer-modified-p)
3609	(let ((recent-save (recent-auto-save-p))
3610	      setmodes)
3611	  ;; On VMS, rename file and buffer to get rid of version number.
3612	  (if (and (eq system-type 'vax-vms)
3613		   (not (string= buffer-file-name
3614				 (file-name-sans-versions buffer-file-name))))
3615	      (let (buffer-new-name)
3616		;; Strip VMS version number before save.
3617		(setq buffer-file-name
3618		      (file-name-sans-versions buffer-file-name))
3619		;; Construct a (unique) buffer name to correspond.
3620		(let ((buf (create-file-buffer (downcase buffer-file-name))))
3621		  (setq buffer-new-name (buffer-name buf))
3622		  (kill-buffer buf))
3623		(rename-buffer buffer-new-name)))
3624	  ;; If buffer has no file name, ask user for one.
3625	  (or buffer-file-name
3626	      (let ((filename
3627		     (expand-file-name
3628		      (read-file-name "File to save in: ") nil)))
3629		(if (file-exists-p filename)
3630		    (if (file-directory-p filename)
3631			;; Signal an error if the user specified the name of an
3632			;; existing directory.
3633			(error "%s is a directory" filename)
3634		      (unless (y-or-n-p (format "File `%s' exists; overwrite? "
3635						filename))
3636			(error "Canceled")))
3637		  ;; Signal an error if the specified name refers to a
3638		  ;; non-existing directory.
3639		  (let ((dir (file-name-directory filename)))
3640		    (unless (file-directory-p dir)
3641		      (if (file-exists-p dir)
3642			  (error "%s is not a directory" dir)
3643			(error "%s: no such directory" dir)))))
3644		(set-visited-file-name filename)))
3645	  (or (verify-visited-file-modtime (current-buffer))
3646	      (not (file-exists-p buffer-file-name))
3647	      (yes-or-no-p
3648	       (format "%s has changed since visited or saved.  Save anyway? "
3649		       (file-name-nondirectory buffer-file-name)))
3650	      (error "Save not confirmed"))
3651	  (save-restriction
3652	    (widen)
3653	    (save-excursion
3654	      (and (> (point-max) (point-min))
3655		   (not find-file-literally)
3656		   (/= (char-after (1- (point-max))) ?\n)
3657		   (not (and (eq selective-display t)
3658			     (= (char-after (1- (point-max))) ?\r)))
3659		   (or (eq require-final-newline t)
3660		       (eq require-final-newline 'visit-save)
3661		       (and require-final-newline
3662			    (y-or-n-p
3663			     (format "Buffer %s does not end in newline.  Add one? "
3664				     (buffer-name)))))
3665		   (save-excursion
3666		     (goto-char (point-max))
3667		     (insert ?\n))))
3668	    ;; Support VC version backups.
3669	    (vc-before-save)
3670	    (run-hooks 'before-save-hook)
3671	    (or (run-hook-with-args-until-success 'write-contents-functions)
3672		(run-hook-with-args-until-success 'local-write-file-hooks)
3673		(run-hook-with-args-until-success 'write-file-functions)
3674		;; If a hook returned t, file is already "written".
3675		;; Otherwise, write it the usual way now.
3676		(setq setmodes (basic-save-buffer-1)))
3677	    ;; Now we have saved the current buffer.  Let's make sure
3678	    ;; that buffer-file-coding-system is fixed to what
3679	    ;; actually used for saving by binding it locally.
3680	    (if save-buffer-coding-system
3681		(setq save-buffer-coding-system last-coding-system-used)
3682	      (setq buffer-file-coding-system last-coding-system-used))
3683	    (setq buffer-file-number
3684		  (nthcdr 10 (file-attributes buffer-file-name)))
3685	    (if setmodes
3686		(condition-case ()
3687		    (set-file-modes buffer-file-name (car setmodes))
3688		  (error nil))))
3689	  ;; If the auto-save file was recent before this command,
3690	  ;; delete it now.
3691	  (delete-auto-save-file-if-necessary recent-save)
3692	  ;; Support VC `implicit' locking.
3693	  (vc-after-save)
3694	  (run-hooks 'after-save-hook))
3695      (message "(No changes need to be saved)"))))
3696
3697;; This does the "real job" of writing a buffer into its visited file
3698;; and making a backup file.  This is what is normally done
3699;; but inhibited if one of write-file-functions returns non-nil.
3700;; It returns a value (MODES . BACKUPNAME), like backup-buffer.
3701(defun basic-save-buffer-1 ()
3702  (prog1
3703      (if save-buffer-coding-system
3704	  (let ((coding-system-for-write save-buffer-coding-system))
3705	    (basic-save-buffer-2))
3706	(basic-save-buffer-2))
3707    (setq buffer-file-coding-system-explicit last-coding-system-used)))
3708
3709;; This returns a value (MODES . BACKUPNAME), like backup-buffer.
3710(defun basic-save-buffer-2 ()
3711  (let (tempsetmodes setmodes)
3712    (if (not (file-writable-p buffer-file-name))
3713	(let ((dir (file-name-directory buffer-file-name)))
3714	  (if (not (file-directory-p dir))
3715	      (if (file-exists-p dir)
3716		  (error "%s is not a directory" dir)
3717		(error "%s: no such directory" dir))
3718	    (if (not (file-exists-p buffer-file-name))
3719		(error "Directory %s write-protected" dir)
3720	      (if (yes-or-no-p
3721		   (format "File %s is write-protected; try to save anyway? "
3722			   (file-name-nondirectory
3723			    buffer-file-name)))
3724		  (setq tempsetmodes t)
3725		(error "Attempt to save to a file which you aren't allowed to write"))))))
3726    (or buffer-backed-up
3727	(setq setmodes (backup-buffer)))
3728    (let ((dir (file-name-directory buffer-file-name)))
3729      (if (and file-precious-flag
3730	       (file-writable-p dir))
3731	  ;; If file is precious, write temp name, then rename it.
3732	  ;; This requires write access to the containing dir,
3733	  ;; which is why we don't try it if we don't have that access.
3734	  (let ((realname buffer-file-name)
3735		tempname succeed
3736		(umask (default-file-modes))
3737		(old-modtime (visited-file-modtime)))
3738	    ;; Create temp files with strict access rights.  It's easy to
3739	    ;; loosen them later, whereas it's impossible to close the
3740	    ;; time-window of loose permissions otherwise.
3741	    (unwind-protect
3742		(progn
3743		  (clear-visited-file-modtime)
3744		  (set-default-file-modes ?\700)
3745		  ;; Try various temporary names.
3746		  ;; This code follows the example of make-temp-file,
3747		  ;; but it calls write-region in the appropriate way
3748		  ;; for saving the buffer.
3749		  (while (condition-case ()
3750			     (progn
3751			       (setq tempname
3752				     (make-temp-name
3753				      (expand-file-name "tmp" dir)))
3754			       (write-region (point-min) (point-max)
3755					     tempname nil  realname
3756					     buffer-file-truename 'excl)
3757			       nil)
3758			   (file-already-exists t))
3759		    ;; The file was somehow created by someone else between
3760		    ;; `make-temp-name' and `write-region', let's try again.
3761		    nil)
3762		  (setq succeed t))
3763	      ;; Reset the umask.
3764	      (set-default-file-modes umask)
3765	      ;; If we failed, restore the buffer's modtime.
3766	      (unless succeed
3767		(set-visited-file-modtime old-modtime)))
3768	    ;; Since we have created an entirely new file,
3769	    ;; make sure it gets the right permission bits set.
3770	    (setq setmodes (or setmodes
3771 			       (cons (or (file-modes buffer-file-name)
3772					 (logand ?\666 umask))
3773				     buffer-file-name)))
3774	    ;; We succeeded in writing the temp file,
3775	    ;; so rename it.
3776	    (rename-file tempname buffer-file-name t))
3777	;; If file not writable, see if we can make it writable
3778	;; temporarily while we write it.
3779	;; But no need to do so if we have just backed it up
3780	;; (setmodes is set) because that says we're superseding.
3781	(cond ((and tempsetmodes (not setmodes))
3782	       ;; Change the mode back, after writing.
3783	       (setq setmodes (cons (file-modes buffer-file-name) buffer-file-name))
3784	       (set-file-modes buffer-file-name (logior (car setmodes) 128))))
3785	(let (success)
3786	  (unwind-protect
3787	      (progn
3788		(write-region (point-min) (point-max)
3789			      buffer-file-name nil t buffer-file-truename)
3790		(setq success t))
3791	    ;; If we get an error writing the new file, and we made
3792	    ;; the backup by renaming, undo the backing-up.
3793	    (and setmodes (not success)
3794		 (progn
3795		   (rename-file (cdr setmodes) buffer-file-name t)
3796		   (setq buffer-backed-up nil)))))))
3797    setmodes))
3798
3799(defun diff-buffer-with-file (&optional buffer)
3800  "View the differences between BUFFER and its associated file.
3801This requires the external program `diff' to be in your `exec-path'."
3802  (interactive "bBuffer: ")
3803  (with-current-buffer (get-buffer (or buffer (current-buffer)))
3804    (if (and buffer-file-name
3805	     (file-exists-p buffer-file-name))
3806	(let ((tempfile (make-temp-file "buffer-content-")))
3807	  (unwind-protect
3808	      (save-restriction
3809		(widen)
3810		(write-region (point-min) (point-max) tempfile nil 'nomessage)
3811		(diff buffer-file-name tempfile nil t)
3812		(sit-for 0))
3813	    (when (file-exists-p tempfile)
3814	      (delete-file tempfile))))
3815      (message "Buffer %s has no associated file on disc" (buffer-name))
3816      ;; Display that message for 1 second so that user can read it
3817      ;; in the minibuffer.
3818      (sit-for 1)))
3819  ;; return always nil, so that save-buffers-kill-emacs will not move
3820  ;; over to the next unsaved buffer when calling `d'.
3821  nil)
3822
3823(defvar save-some-buffers-action-alist
3824  '((?\C-r
3825     (lambda (buf)
3826       (view-buffer buf
3827		    (lambda (ignore)
3828		      (exit-recursive-edit)))
3829       (recursive-edit)
3830       ;; Return nil to ask about BUF again.
3831       nil)
3832     "view this buffer")
3833    (?d (lambda (buf)
3834	  (save-window-excursion
3835	    (diff-buffer-with-file buf))
3836	  (view-buffer (get-buffer-create "*Diff*")
3837		       (lambda (ignore) (exit-recursive-edit)))
3838	  (recursive-edit)
3839	  nil)
3840	"view changes in this buffer"))
3841  "ACTION-ALIST argument used in call to `map-y-or-n-p'.")
3842
3843(defvar buffer-save-without-query nil
3844  "Non-nil means `save-some-buffers' should save this buffer without asking.")
3845(make-variable-buffer-local 'buffer-save-without-query)
3846
3847(defun save-some-buffers (&optional arg pred)
3848  "Save some modified file-visiting buffers.  Asks user about each one.
3849You can answer `y' to save, `n' not to save, `C-r' to look at the
3850buffer in question with `view-buffer' before deciding or `d' to
3851view the differences using `diff-buffer-with-file'.
3852
3853Optional argument (the prefix) non-nil means save all with no questions.
3854Optional second argument PRED determines which buffers are considered:
3855If PRED is nil, all the file-visiting buffers are considered.
3856If PRED is t, then certain non-file buffers will also be considered.
3857If PRED is a zero-argument function, it indicates for each buffer whether
3858to consider it or not when called with that buffer current.
3859
3860See `save-some-buffers-action-alist' if you want to
3861change the additional actions you can take on files."
3862  (interactive "P")
3863  (save-window-excursion
3864    (let* (queried some-automatic
3865	   files-done abbrevs-done)
3866      (dolist (buffer (buffer-list))
3867	;; First save any buffers that we're supposed to save unconditionally.
3868	;; That way the following code won't ask about them.
3869	(with-current-buffer buffer
3870	  (when (and buffer-save-without-query (buffer-modified-p))
3871	    (setq some-automatic t)
3872	    (save-buffer))))
3873      ;; Ask about those buffers that merit it,
3874      ;; and record the number thus saved.
3875      (setq files-done
3876	    (map-y-or-n-p
3877	     (function
3878	      (lambda (buffer)
3879		(and (buffer-modified-p buffer)
3880		     (not (buffer-base-buffer buffer))
3881		     (or
3882		      (buffer-file-name buffer)
3883		      (and pred
3884			   (progn
3885			     (set-buffer buffer)
3886			     (and buffer-offer-save (> (buffer-size) 0)))))
3887		     (or (not (functionp pred))
3888			 (with-current-buffer buffer (funcall pred)))
3889		     (if arg
3890			 t
3891		       (setq queried t)
3892		       (if (buffer-file-name buffer)
3893			   (format "Save file %s? "
3894				   (buffer-file-name buffer))
3895			 (format "Save buffer %s? "
3896				 (buffer-name buffer)))))))
3897	     (function
3898	      (lambda (buffer)
3899		(set-buffer buffer)
3900		(save-buffer)))
3901	     (buffer-list)
3902	     '("buffer" "buffers" "save")
3903	     save-some-buffers-action-alist))
3904      ;; Maybe to save abbrevs, and record whether
3905      ;; we either saved them or asked to.
3906      (and save-abbrevs abbrevs-changed
3907	   (progn
3908	     (if (or arg
3909		     (eq save-abbrevs 'silently)
3910		     (y-or-n-p (format "Save abbrevs in %s? "
3911				       abbrev-file-name)))
3912		 (write-abbrev-file nil))
3913	     ;; Don't keep bothering user if he says no.
3914	     (setq abbrevs-changed nil)
3915	     (setq abbrevs-done t)))
3916      (or queried (> files-done 0) abbrevs-done
3917	  (message (if some-automatic
3918		       "(Some special files were saved without asking)"
3919		     "(No files need saving)"))))))
3920
3921(defun not-modified (&optional arg)
3922  "Mark current buffer as unmodified, not needing to be saved.
3923With prefix arg, mark buffer as modified, so \\[save-buffer] will save.
3924
3925It is not a good idea to use this function in Lisp programs, because it
3926prints a message in the minibuffer.  Instead, use `set-buffer-modified-p'."
3927  (interactive "P")
3928  (message (if arg "Modification-flag set"
3929	       "Modification-flag cleared"))
3930  (set-buffer-modified-p arg))
3931
3932(defun toggle-read-only (&optional arg)
3933  "Change whether this buffer is visiting its file read-only.
3934With arg, set read-only iff arg is positive.
3935If visiting file read-only and `view-read-only' is non-nil, enter view mode."
3936  (interactive "P")
3937  (if (and arg
3938           (if (> (prefix-numeric-value arg) 0) buffer-read-only
3939             (not buffer-read-only)))  ; If buffer-read-only is set correctly,
3940      nil			       ; do nothing.
3941    ;; Toggle.
3942    (cond
3943     ((and buffer-read-only view-mode)
3944      (View-exit-and-edit)
3945      (make-local-variable 'view-read-only)
3946      (setq view-read-only t))		; Must leave view mode.
3947     ((and (not buffer-read-only) view-read-only
3948	   ;; If view-mode is already active, `view-mode-enter' is a nop.
3949	   (not view-mode)
3950           (not (eq (get major-mode 'mode-class) 'special)))
3951      (view-mode-enter))
3952     (t (setq buffer-read-only (not buffer-read-only))
3953        (force-mode-line-update)))
3954    (if (vc-backend buffer-file-name)
3955        (message "%s" (substitute-command-keys
3956                  (concat "File is under version-control; "
3957                          "use \\[vc-next-action] to check in/out"))))))
3958
3959(defun insert-file (filename)
3960  "Insert contents of file FILENAME into buffer after point.
3961Set mark after the inserted text.
3962
3963This function is meant for the user to run interactively.
3964Don't call it from programs!  Use `insert-file-contents' instead.
3965\(Its calling sequence is different; see its documentation)."
3966  (interactive "*fInsert file: ")
3967  (insert-file-1 filename #'insert-file-contents))
3968
3969(defun append-to-file (start end filename)
3970  "Append the contents of the region to the end of file FILENAME.
3971When called from a function, expects three arguments,
3972START, END and FILENAME.  START and END are buffer positions
3973saying what text to write."
3974  (interactive "r\nFAppend to file: ")
3975  (write-region start end filename t))
3976
3977(defun file-newest-backup (filename)
3978  "Return most recent backup file for FILENAME or nil if no backups exist."
3979  ;; `make-backup-file-name' will get us the right directory for
3980  ;; ordinary or numeric backups.  It might create a directory for
3981  ;; backups as a side-effect, according to `backup-directory-alist'.
3982  (let* ((filename (file-name-sans-versions
3983		    (make-backup-file-name (expand-file-name filename))))
3984	 (file (file-name-nondirectory filename))
3985	 (dir  (file-name-directory    filename))
3986	 (comp (file-name-all-completions file dir))
3987         (newest nil)
3988         tem)
3989    (while comp
3990      (setq tem (pop comp))
3991      (cond ((and (backup-file-name-p tem)
3992                  (string= (file-name-sans-versions tem) file))
3993             (setq tem (concat dir tem))
3994             (if (or (null newest)
3995                     (file-newer-than-file-p tem newest))
3996                 (setq newest tem)))))
3997    newest))
3998
3999(defun rename-uniquely ()
4000  "Rename current buffer to a similar name not already taken.
4001This function is useful for creating multiple shell process buffers
4002or multiple mail buffers, etc."
4003  (interactive)
4004  (save-match-data
4005    (let ((base-name (buffer-name)))
4006      (and (string-match "<[0-9]+>\\'" base-name)
4007	   (not (and buffer-file-name
4008		     (string= base-name
4009			      (file-name-nondirectory buffer-file-name))))
4010	   ;; If the existing buffer name has a <NNN>,
4011	   ;; which isn't part of the file name (if any),
4012	   ;; then get rid of that.
4013	   (setq base-name (substring base-name 0 (match-beginning 0))))
4014      (rename-buffer (generate-new-buffer-name base-name))
4015      (force-mode-line-update))))
4016
4017(defun make-directory (dir &optional parents)
4018  "Create the directory DIR and any nonexistent parent dirs.
4019Interactively, the default choice of directory to create
4020is the current default directory for file names.
4021That is useful when you have visited a file in a nonexistent directory.
4022
4023Noninteractively, the second (optional) argument PARENTS says whether
4024to create parent directories if they don't exist.  Interactively,
4025this happens by default."
4026  (interactive
4027   (list (read-file-name "Make directory: " default-directory default-directory
4028			 nil nil)
4029	 t))
4030  ;; If default-directory is a remote directory,
4031  ;; make sure we find its make-directory handler.
4032  (setq dir (expand-file-name dir))
4033  (let ((handler (find-file-name-handler dir 'make-directory)))
4034    (if handler
4035	(funcall handler 'make-directory dir parents)
4036      (if (not parents)
4037	  (make-directory-internal dir)
4038	(let ((dir (directory-file-name (expand-file-name dir)))
4039	      create-list)
4040	  (while (not (file-exists-p dir))
4041	    (setq create-list (cons dir create-list)
4042		  dir (directory-file-name (file-name-directory dir))))
4043	  (while create-list
4044	    (make-directory-internal (car create-list))
4045	    (setq create-list (cdr create-list))))))))
4046
4047(put 'revert-buffer-function 'permanent-local t)
4048(defvar revert-buffer-function nil
4049  "Function to use to revert this buffer, or nil to do the default.
4050The function receives two arguments IGNORE-AUTO and NOCONFIRM,
4051which are the arguments that `revert-buffer' received.")
4052
4053(put 'revert-buffer-insert-file-contents-function 'permanent-local t)
4054(defvar revert-buffer-insert-file-contents-function nil
4055  "Function to use to insert contents when reverting this buffer.
4056Gets two args, first the nominal file name to use,
4057and second, t if reading the auto-save file.
4058
4059The function you specify is responsible for updating (or preserving) point.")
4060
4061(defvar buffer-stale-function nil
4062  "Function to check whether a non-file buffer needs reverting.
4063This should be a function with one optional argument NOCONFIRM.
4064Auto Revert Mode passes t for NOCONFIRM.  The function should return
4065non-nil if the buffer should be reverted.  A return value of
4066`fast' means that the need for reverting was not checked, but
4067that reverting the buffer is fast.  The buffer is current when
4068this function is called.
4069
4070The idea behind the NOCONFIRM argument is that it should be
4071non-nil if the buffer is going to be reverted without asking the
4072user.  In such situations, one has to be careful with potentially
4073time consuming operations.
4074
4075For more information on how this variable is used by Auto Revert mode,
4076see Info node `(emacs)Supporting additional buffers'.")
4077
4078(defvar before-revert-hook nil
4079  "Normal hook for `revert-buffer' to run before reverting.
4080If `revert-buffer-function' is used to override the normal revert
4081mechanism, this hook is not used.")
4082
4083(defvar after-revert-hook nil
4084  "Normal hook for `revert-buffer' to run after reverting.
4085Note that the hook value that it runs is the value that was in effect
4086before reverting; that makes a difference if you have buffer-local
4087hook functions.
4088
4089If `revert-buffer-function' is used to override the normal revert
4090mechanism, this hook is not used.")
4091
4092(defvar revert-buffer-internal-hook)
4093
4094(defun revert-buffer (&optional ignore-auto noconfirm preserve-modes)
4095  "Replace current buffer text with the text of the visited file on disk.
4096This undoes all changes since the file was visited or saved.
4097With a prefix argument, offer to revert from latest auto-save file, if
4098that is more recent than the visited file.
4099
4100This command also works for special buffers that contain text which
4101doesn't come from a file, but reflects some other data base instead:
4102for example, Dired buffers and `buffer-list' buffers.  In these cases,
4103it reconstructs the buffer contents from the appropriate data base.
4104
4105When called from Lisp, the first argument is IGNORE-AUTO; only offer
4106to revert from the auto-save file when this is nil.  Note that the
4107sense of this argument is the reverse of the prefix argument, for the
4108sake of backward compatibility.  IGNORE-AUTO is optional, defaulting
4109to nil.
4110
4111Optional second argument NOCONFIRM means don't ask for confirmation at
4112all.  \(The variable `revert-without-query' offers another way to
4113revert buffers without querying for confirmation.)
4114
4115Optional third argument PRESERVE-MODES non-nil means don't alter
4116the files modes.  Normally we reinitialize them using `normal-mode'.
4117
4118If the value of `revert-buffer-function' is non-nil, it is called to
4119do all the work for this command.  Otherwise, the hooks
4120`before-revert-hook' and `after-revert-hook' are run at the beginning
4121and the end, and if `revert-buffer-insert-file-contents-function' is
4122non-nil, it is called instead of rereading visited file contents."
4123
4124  ;; I admit it's odd to reverse the sense of the prefix argument, but
4125  ;; there is a lot of code out there which assumes that the first
4126  ;; argument should be t to avoid consulting the auto-save file, and
4127  ;; there's no straightforward way to encourage authors to notice a
4128  ;; reversal of the argument sense.  So I'm just changing the user
4129  ;; interface, but leaving the programmatic interface the same.
4130  (interactive (list (not current-prefix-arg)))
4131  (if revert-buffer-function
4132      (funcall revert-buffer-function ignore-auto noconfirm)
4133    (with-current-buffer (or (buffer-base-buffer (current-buffer))
4134			     (current-buffer))
4135      (let* ((auto-save-p (and (not ignore-auto)
4136			       (recent-auto-save-p)
4137			       buffer-auto-save-file-name
4138			       (file-readable-p buffer-auto-save-file-name)
4139			       (y-or-n-p
4140     "Buffer has been auto-saved recently.  Revert from auto-save file? ")))
4141	     (file-name (if auto-save-p
4142			    buffer-auto-save-file-name
4143			  buffer-file-name)))
4144	(cond ((null file-name)
4145	       (error "Buffer does not seem to be associated with any file"))
4146	      ((or noconfirm
4147		   (and (not (buffer-modified-p))
4148			(catch 'found
4149			  (dolist (regexp revert-without-query)
4150			    (when (string-match regexp file-name)
4151			      (throw 'found t)))))
4152		   (yes-or-no-p (format "Revert buffer from file %s? "
4153					file-name)))
4154	       (run-hooks 'before-revert-hook)
4155	       ;; If file was backed up but has changed since,
4156	       ;; we shd make another backup.
4157	       (and (not auto-save-p)
4158		    (not (verify-visited-file-modtime (current-buffer)))
4159		    (setq buffer-backed-up nil))
4160	       ;; Effectively copy the after-revert-hook status,
4161	       ;; since after-find-file will clobber it.
4162	       (let ((global-hook (default-value 'after-revert-hook))
4163		     (local-hook (when (local-variable-p 'after-revert-hook)
4164				   after-revert-hook))
4165		     (inhibit-read-only t))
4166		 (cond
4167		  (revert-buffer-insert-file-contents-function
4168		   (unless (eq buffer-undo-list t)
4169		     ;; Get rid of all undo records for this buffer.
4170		     (setq buffer-undo-list nil))
4171		   ;; Don't make undo records for the reversion.
4172		   (let ((buffer-undo-list t))
4173		     (funcall revert-buffer-insert-file-contents-function
4174			      file-name auto-save-p)))
4175		  ((not (file-exists-p file-name))
4176		   (error (if buffer-file-number
4177			      "File %s no longer exists!"
4178			    "Cannot revert nonexistent file %s")
4179			  file-name))
4180		  ((not (file-readable-p file-name))
4181		   (error (if buffer-file-number
4182			      "File %s no longer readable!"
4183			    "Cannot revert unreadable file %s")
4184			  file-name))
4185		  (t
4186		   ;; Bind buffer-file-name to nil
4187		   ;; so that we don't try to lock the file.
4188		   (let ((buffer-file-name nil))
4189		     (or auto-save-p
4190			 (unlock-buffer)))
4191		   (widen)
4192		   (let ((coding-system-for-read
4193			  ;; Auto-saved file should be read by Emacs'
4194			  ;; internal coding.
4195			  (if auto-save-p 'auto-save-coding
4196			    (or coding-system-for-read
4197				buffer-file-coding-system-explicit))))
4198		     (if (and (not enable-multibyte-characters)
4199			      coding-system-for-read
4200			      (not (memq (coding-system-base
4201					  coding-system-for-read)
4202					 '(no-conversion raw-text))))
4203			 ;; As a coding system suitable for multibyte
4204			 ;; buffer is specified, make the current
4205			 ;; buffer multibyte.
4206			 (set-buffer-multibyte t))
4207
4208		     ;; This force after-insert-file-set-coding
4209		     ;; (called from insert-file-contents) to set
4210		     ;; buffer-file-coding-system to a proper value.
4211		     (kill-local-variable 'buffer-file-coding-system)
4212
4213		     ;; Note that this preserves point in an intelligent way.
4214		     (if preserve-modes
4215			 (let ((buffer-file-format buffer-file-format))
4216			   (insert-file-contents file-name (not auto-save-p)
4217						 nil nil t))
4218		       (insert-file-contents file-name (not auto-save-p)
4219					     nil nil t)))))
4220		 ;; Recompute the truename in case changes in symlinks
4221		 ;; have changed the truename.
4222		 (setq buffer-file-truename
4223		       (abbreviate-file-name (file-truename buffer-file-name)))
4224		 (after-find-file nil nil t t preserve-modes)
4225		 ;; Run after-revert-hook as it was before we reverted.
4226		 (setq-default revert-buffer-internal-hook global-hook)
4227		 (if local-hook
4228		     (set (make-local-variable 'revert-buffer-internal-hook)
4229			  local-hook)
4230		   (kill-local-variable 'revert-buffer-internal-hook))
4231		 (run-hooks 'revert-buffer-internal-hook))
4232	       t))))))
4233
4234(defun recover-this-file ()
4235  "Recover the visited file--get contents from its last auto-save file."
4236  (interactive)
4237  (recover-file buffer-file-name))
4238
4239(defun recover-file (file)
4240  "Visit file FILE, but get contents from its last auto-save file."
4241  ;; Actually putting the file name in the minibuffer should be used
4242  ;; only rarely.
4243  ;; Not just because users often use the default.
4244  (interactive "FRecover file: ")
4245  (setq file (expand-file-name file))
4246  (if (auto-save-file-name-p (file-name-nondirectory file))
4247      (error "%s is an auto-save file" (abbreviate-file-name file)))
4248  (let ((file-name (let ((buffer-file-name file))
4249		     (make-auto-save-file-name))))
4250    (cond ((if (file-exists-p file)
4251	       (not (file-newer-than-file-p file-name file))
4252	     (not (file-exists-p file-name)))
4253	   (error "Auto-save file %s not current"
4254		  (abbreviate-file-name file-name)))
4255	  ((save-window-excursion
4256	     (with-output-to-temp-buffer "*Directory*"
4257	       (buffer-disable-undo standard-output)
4258	       (save-excursion
4259		 (let ((switches dired-listing-switches))
4260		   (if (file-symlink-p file)
4261		       (setq switches (concat switches "L")))
4262		   (set-buffer standard-output)
4263		   ;; Use insert-directory-safely, not insert-directory,
4264		   ;; because these files might not exist.  In particular,
4265		   ;; FILE might not exist if the auto-save file was for
4266		   ;; a buffer that didn't visit a file, such as "*mail*".
4267		   ;; The code in v20.x called `ls' directly, so we need
4268		   ;; to emulate what `ls' did in that case.
4269		   (insert-directory-safely file switches)
4270		   (insert-directory-safely file-name switches))))
4271	     (yes-or-no-p (format "Recover auto save file %s? " file-name)))
4272	   (switch-to-buffer (find-file-noselect file t))
4273	   (let ((inhibit-read-only t)
4274		 ;; Keep the current buffer-file-coding-system.
4275		 (coding-system buffer-file-coding-system)
4276		 ;; Auto-saved file should be read with special coding.
4277		 (coding-system-for-read 'auto-save-coding))
4278	     (erase-buffer)
4279	     (insert-file-contents file-name nil)
4280	     (set-buffer-file-coding-system coding-system))
4281	   (after-find-file nil nil t))
4282	  (t (error "Recover-file cancelled")))))
4283
4284(defun recover-session ()
4285  "Recover auto save files from a previous Emacs session.
4286This command first displays a Dired buffer showing you the
4287previous sessions that you could recover from.
4288To choose one, move point to the proper line and then type C-c C-c.
4289Then you'll be asked about a number of files to recover."
4290  (interactive)
4291  (if (null auto-save-list-file-prefix)
4292      (error "You set `auto-save-list-file-prefix' to disable making session files"))
4293  (let ((dir (file-name-directory auto-save-list-file-prefix)))
4294    (unless (file-directory-p dir)
4295      (make-directory dir t))
4296    (unless (directory-files dir nil
4297			     (concat "\\`" (regexp-quote
4298					    (file-name-nondirectory
4299					     auto-save-list-file-prefix)))
4300			     t)
4301      (error "No previous sessions to recover")))
4302  (let ((ls-lisp-support-shell-wildcards t))
4303    (dired (concat auto-save-list-file-prefix "*")
4304	   (concat dired-listing-switches "t")))
4305  (save-excursion
4306    (goto-char (point-min))
4307    (or (looking-at " Move to the session you want to recover,")
4308	(let ((inhibit-read-only t))
4309	  ;; Each line starts with a space
4310	  ;; so that Font Lock mode won't highlight the first character.
4311	  (insert " Move to the session you want to recover,\n"
4312		  " then type C-c C-c to select it.\n\n"
4313		  " You can also delete some of these files;\n"
4314		  " type d on a line to mark that file for deletion.\n\n"))))
4315  (use-local-map (nconc (make-sparse-keymap) (current-local-map)))
4316  (define-key (current-local-map) "\C-c\C-c" 'recover-session-finish))
4317
4318(defun recover-session-finish ()
4319  "Choose one saved session to recover auto-save files from.
4320This command is used in the special Dired buffer created by
4321\\[recover-session]."
4322  (interactive)
4323  ;; Get the name of the session file to recover from.
4324  (let ((file (dired-get-filename))
4325	files
4326	(buffer (get-buffer-create " *recover*")))
4327    (dired-unmark 1)
4328    (dired-do-flagged-delete t)
4329    (unwind-protect
4330	(save-excursion
4331	  ;; Read in the auto-save-list file.
4332	  (set-buffer buffer)
4333	  (erase-buffer)
4334	  (insert-file-contents file)
4335	  ;; Loop thru the text of that file
4336	  ;; and get out the names of the files to recover.
4337	  (while (not (eobp))
4338	    (let (thisfile autofile)
4339	      (if (eolp)
4340		  ;; This is a pair of lines for a non-file-visiting buffer.
4341		  ;; Get the auto-save file name and manufacture
4342		  ;; a "visited file name" from that.
4343		  (progn
4344		    (forward-line 1)
4345		    ;; If there is no auto-save file name, the
4346		    ;; auto-save-list file is probably corrupted.
4347		    (unless (eolp)
4348		      (setq autofile
4349			    (buffer-substring-no-properties
4350			     (point)
4351			     (line-end-position)))
4352		      (setq thisfile
4353			    (expand-file-name
4354			     (substring
4355			      (file-name-nondirectory autofile)
4356			      1 -1)
4357			     (file-name-directory autofile))))
4358		    (forward-line 1))
4359		;; This pair of lines is a file-visiting
4360		;; buffer.  Use the visited file name.
4361		(progn
4362		  (setq thisfile
4363			(buffer-substring-no-properties
4364			 (point) (progn (end-of-line) (point))))
4365		  (forward-line 1)
4366		  (setq autofile
4367			(buffer-substring-no-properties
4368			 (point) (progn (end-of-line) (point))))
4369		  (forward-line 1)))
4370	      ;; Ignore a file if its auto-save file does not exist now.
4371	      (if (and autofile (file-exists-p autofile))
4372		  (setq files (cons thisfile files)))))
4373	  (setq files (nreverse files))
4374	  ;; The file contains a pair of line for each auto-saved buffer.
4375	  ;; The first line of the pair contains the visited file name
4376	  ;; or is empty if the buffer was not visiting a file.
4377	  ;; The second line is the auto-save file name.
4378	  (if files
4379	      (map-y-or-n-p  "Recover %s? "
4380			     (lambda (file)
4381			       (condition-case nil
4382				   (save-excursion (recover-file file))
4383				 (error
4384				  "Failed to recover `%s'" file)))
4385			     files
4386			     '("file" "files" "recover"))
4387	    (message "No files can be recovered from this session now")))
4388      (kill-buffer buffer))))
4389
4390(defun kill-some-buffers (&optional list)
4391  "Kill some buffers.  Asks the user whether to kill each one of them.
4392Non-interactively, if optional argument LIST is non-nil, it
4393specifies the list of buffers to kill, asking for approval for each one."
4394  (interactive)
4395  (if (null list)
4396      (setq list (buffer-list)))
4397  (while list
4398    (let* ((buffer (car list))
4399	   (name (buffer-name buffer)))
4400      (and name				; Can be nil for an indirect buffer
4401					; if we killed the base buffer.
4402	   (not (string-equal name ""))
4403	   (/= (aref name 0) ?\s)
4404	   (yes-or-no-p
4405	    (format "Buffer %s %s.  Kill? "
4406		    name
4407		    (if (buffer-modified-p buffer)
4408			"HAS BEEN EDITED" "is unmodified")))
4409	   (kill-buffer buffer)))
4410    (setq list (cdr list))))
4411
4412(defun auto-save-mode (arg)
4413  "Toggle auto-saving of contents of current buffer.
4414With prefix argument ARG, turn auto-saving on if positive, else off."
4415  (interactive "P")
4416  (setq buffer-auto-save-file-name
4417        (and (if (null arg)
4418		 (or (not buffer-auto-save-file-name)
4419		     ;; If auto-save is off because buffer has shrunk,
4420		     ;; then toggling should turn it on.
4421		     (< buffer-saved-size 0))
4422	       (or (eq arg t) (listp arg) (and (integerp arg) (> arg 0))))
4423	     (if (and buffer-file-name auto-save-visited-file-name
4424		      (not buffer-read-only))
4425		 buffer-file-name
4426	       (make-auto-save-file-name))))
4427  ;; If -1 was stored here, to temporarily turn off saving,
4428  ;; turn it back on.
4429  (and (< buffer-saved-size 0)
4430       (setq buffer-saved-size 0))
4431  (if (interactive-p)
4432      (message "Auto-save %s (in this buffer)"
4433	       (if buffer-auto-save-file-name "on" "off")))
4434  buffer-auto-save-file-name)
4435
4436(defun rename-auto-save-file ()
4437  "Adjust current buffer's auto save file name for current conditions.
4438Also rename any existing auto save file, if it was made in this session."
4439  (let ((osave buffer-auto-save-file-name))
4440    (setq buffer-auto-save-file-name
4441	  (make-auto-save-file-name))
4442    (if (and osave buffer-auto-save-file-name
4443	     (not (string= buffer-auto-save-file-name buffer-file-name))
4444	     (not (string= buffer-auto-save-file-name osave))
4445	     (file-exists-p osave)
4446	     (recent-auto-save-p))
4447	(rename-file osave buffer-auto-save-file-name t))))
4448
4449(defun make-auto-save-file-name ()
4450  "Return file name to use for auto-saves of current buffer.
4451Does not consider `auto-save-visited-file-name' as that variable is checked
4452before calling this function.  You can redefine this for customization.
4453See also `auto-save-file-name-p'."
4454  (if buffer-file-name
4455      (let ((handler (find-file-name-handler buffer-file-name
4456					     'make-auto-save-file-name)))
4457	(if handler
4458	    (funcall handler 'make-auto-save-file-name)
4459	  (let ((list auto-save-file-name-transforms)
4460		(filename buffer-file-name)
4461		result uniq)
4462	    ;; Apply user-specified translations
4463	    ;; to the file name.
4464	    (while (and list (not result))
4465	      (if (string-match (car (car list)) filename)
4466		  (setq result (replace-match (cadr (car list)) t nil
4467					      filename)
4468			uniq (car (cddr (car list)))))
4469	      (setq list (cdr list)))
4470	    (if result
4471		(if uniq
4472		    (setq filename (concat
4473				    (file-name-directory result)
4474				    (subst-char-in-string
4475				     ?/ ?!
4476				     (replace-regexp-in-string "!" "!!"
4477							       filename))))
4478		  (setq filename result)))
4479	    (setq result
4480		  (if (and (eq system-type 'ms-dos)
4481			   (not (msdos-long-file-names)))
4482		      ;; We truncate the file name to DOS 8+3 limits
4483		      ;; before doing anything else, because the regexp
4484		      ;; passed to string-match below cannot handle
4485		      ;; extensions longer than 3 characters, multiple
4486		      ;; dots, and other atrocities.
4487		      (let ((fn (dos-8+3-filename
4488				 (file-name-nondirectory buffer-file-name))))
4489			(string-match
4490			 "\\`\\([^.]+\\)\\(\\.\\(..?\\)?.?\\|\\)\\'"
4491			 fn)
4492			(concat (file-name-directory buffer-file-name)
4493				"#" (match-string 1 fn)
4494				"." (match-string 3 fn) "#"))
4495		    (concat (file-name-directory filename)
4496			    "#"
4497			    (file-name-nondirectory filename)
4498			    "#")))
4499	    ;; Make sure auto-save file names don't contain characters
4500	    ;; invalid for the underlying filesystem.
4501	    (if (and (memq system-type '(ms-dos windows-nt cygwin))
4502		     ;; Don't modify remote (ange-ftp) filenames
4503		     (not (string-match "^/\\w+@[-A-Za-z0-9._]+:" result)))
4504		(convert-standard-filename result)
4505	      result))))
4506
4507    ;; Deal with buffers that don't have any associated files.  (Mail
4508    ;; mode tends to create a good number of these.)
4509
4510    (let ((buffer-name (buffer-name))
4511	  (limit 0)
4512	  file-name)
4513      ;; Eliminate all slashes and backslashes by
4514      ;; replacing them with sequences that start with %.
4515      ;; Quote % also, to keep distinct names distinct.
4516      (while (string-match "[/\\%]" buffer-name limit)
4517	(let* ((character (aref buffer-name (match-beginning 0)))
4518	       (replacement
4519		(cond ((eq character ?%) "%%")
4520		      ((eq character ?/) "%+")
4521		      ((eq character ?\\) "%-"))))
4522	  (setq buffer-name (replace-match replacement t t buffer-name))
4523	  (setq limit (1+ (match-end 0)))))
4524      ;; Generate the file name.
4525      (setq file-name
4526	    (make-temp-file
4527	     (let ((fname
4528		    (expand-file-name
4529		     (format "#%s#" buffer-name)
4530		     ;; Try a few alternative directories, to get one we can
4531		     ;; write it.
4532		     (cond
4533		      ((file-writable-p default-directory) default-directory)
4534		      ((file-writable-p "/var/tmp/") "/var/tmp/")
4535		      ("~/")))))
4536	       (if (and (memq system-type '(ms-dos windows-nt cygwin))
4537			;; Don't modify remote (ange-ftp) filenames
4538			(not (string-match "^/\\w+@[-A-Za-z0-9._]+:" fname)))
4539		   ;; The call to convert-standard-filename is in case
4540		   ;; buffer-name includes characters not allowed by the
4541		   ;; DOS/Windows filesystems.  make-temp-file writes to the
4542		   ;; file it creates, so we must fix the file name _before_
4543		   ;; make-temp-file is called.
4544		   (convert-standard-filename fname)
4545		 fname))
4546	     nil "#"))
4547      ;; make-temp-file creates the file,
4548      ;; but we don't want it to exist until we do an auto-save.
4549      (condition-case ()
4550	  (delete-file file-name)
4551	(file-error nil))
4552      file-name)))
4553
4554(defun auto-save-file-name-p (filename)
4555  "Return non-nil if FILENAME can be yielded by `make-auto-save-file-name'.
4556FILENAME should lack slashes.  You can redefine this for customization."
4557  (string-match "^#.*#$" filename))
4558
4559(defun wildcard-to-regexp (wildcard)
4560  "Given a shell file name pattern WILDCARD, return an equivalent regexp.
4561The generated regexp will match a filename iff the filename
4562matches that wildcard according to shell rules.  Only wildcards known
4563by `sh' are supported."
4564  (let* ((i (string-match "[[.*+\\^$?]" wildcard))
4565	 ;; Copy the initial run of non-special characters.
4566	 (result (substring wildcard 0 i))
4567	 (len (length wildcard)))
4568    ;; If no special characters, we're almost done.
4569    (if i
4570	(while (< i len)
4571	  (let ((ch (aref wildcard i))
4572		j)
4573	    (setq
4574	     result
4575	     (concat result
4576		     (cond
4577		      ((and (eq ch ?\[)
4578			    (< (1+ i) len)
4579			    (eq (aref wildcard (1+ i)) ?\]))
4580		       "\\[")
4581		      ((eq ch ?\[)	; [...] maps to regexp char class
4582		       (progn
4583			 (setq i (1+ i))
4584			 (concat
4585			  (cond
4586			   ((eq (aref wildcard i) ?!) ; [!...] -> [^...]
4587			    (progn
4588			      (setq i (1+ i))
4589			      (if (eq (aref wildcard i) ?\])
4590				  (progn
4591				    (setq i (1+ i))
4592				    "[^]")
4593				"[^")))
4594			   ((eq (aref wildcard i) ?^)
4595			    ;; Found "[^".  Insert a `\0' character
4596			    ;; (which cannot happen in a filename)
4597			    ;; into the character class, so that `^'
4598			    ;; is not the first character after `[',
4599			    ;; and thus non-special in a regexp.
4600			    (progn
4601			      (setq i (1+ i))
4602			      "[\000^"))
4603			   ((eq (aref wildcard i) ?\])
4604			    ;; I don't think `]' can appear in a
4605			    ;; character class in a wildcard, but
4606			    ;; let's be general here.
4607			    (progn
4608			      (setq i (1+ i))
4609			      "[]"))
4610			   (t "["))
4611			  (prog1	; copy everything upto next `]'.
4612			      (substring wildcard
4613					 i
4614					 (setq j (string-match
4615						  "]" wildcard i)))
4616			    (setq i (if j (1- j) (1- len)))))))
4617		      ((eq ch ?.)  "\\.")
4618		      ((eq ch ?*)  "[^\000]*")
4619		      ((eq ch ?+)  "\\+")
4620		      ((eq ch ?^)  "\\^")
4621		      ((eq ch ?$)  "\\$")
4622		      ((eq ch ?\\) "\\\\") ; probably cannot happen...
4623		      ((eq ch ??)  "[^\000]")
4624		      (t (char-to-string ch)))))
4625	    (setq i (1+ i)))))
4626    ;; Shell wildcards should match the entire filename,
4627    ;; not its part.  Make the regexp say so.
4628    (concat "\\`" result "\\'")))
4629
4630(defcustom list-directory-brief-switches
4631  (if (eq system-type 'vax-vms) "" "-CF")
4632  "Switches for `list-directory' to pass to `ls' for brief listing."
4633  :type 'string
4634  :group 'dired)
4635
4636(defcustom list-directory-verbose-switches
4637  (if (eq system-type 'vax-vms)
4638      "/PROTECTION/SIZE/DATE/OWNER/WIDTH=(OWNER:10)"
4639    "-l")
4640  "Switches for `list-directory' to pass to `ls' for verbose listing."
4641  :type 'string
4642  :group 'dired)
4643
4644(defun file-expand-wildcards (pattern &optional full)
4645  "Expand wildcard pattern PATTERN.
4646This returns a list of file names which match the pattern.
4647
4648If PATTERN is written as an absolute file name,
4649the values are absolute also.
4650
4651If PATTERN is written as a relative file name, it is interpreted
4652relative to the current default directory, `default-directory'.
4653The file names returned are normally also relative to the current
4654default directory.  However, if FULL is non-nil, they are absolute."
4655  (save-match-data
4656    (let* ((nondir (file-name-nondirectory pattern))
4657	   (dirpart (file-name-directory pattern))
4658	   ;; A list of all dirs that DIRPART specifies.
4659	   ;; This can be more than one dir
4660	   ;; if DIRPART contains wildcards.
4661	   (dirs (if (and dirpart (string-match "[[*?]" dirpart))
4662		     (mapcar 'file-name-as-directory
4663			     (file-expand-wildcards (directory-file-name dirpart)))
4664		   (list dirpart)))
4665	   contents)
4666      (while dirs
4667	(when (or (null (car dirs))	; Possible if DIRPART is not wild.
4668		  (file-directory-p (directory-file-name (car dirs))))
4669	  (let ((this-dir-contents
4670		 ;; Filter out "." and ".."
4671		 (delq nil
4672		       (mapcar #'(lambda (name)
4673				   (unless (string-match "\\`\\.\\.?\\'"
4674							 (file-name-nondirectory name))
4675				     name))
4676			       (directory-files (or (car dirs) ".") full
4677						(wildcard-to-regexp nondir))))))
4678	    (setq contents
4679		  (nconc
4680		   (if (and (car dirs) (not full))
4681		       (mapcar (function (lambda (name) (concat (car dirs) name)))
4682			       this-dir-contents)
4683		     this-dir-contents)
4684		   contents))))
4685	(setq dirs (cdr dirs)))
4686      contents)))
4687
4688(defun list-directory (dirname &optional verbose)
4689  "Display a list of files in or matching DIRNAME, a la `ls'.
4690DIRNAME is globbed by the shell if necessary.
4691Prefix arg (second arg if noninteractive) means supply -l switch to `ls'.
4692Actions controlled by variables `list-directory-brief-switches'
4693and `list-directory-verbose-switches'."
4694  (interactive (let ((pfx current-prefix-arg))
4695		 (list (read-file-name (if pfx "List directory (verbose): "
4696					 "List directory (brief): ")
4697				       nil default-directory nil)
4698		       pfx)))
4699  (let ((switches (if verbose list-directory-verbose-switches
4700		    list-directory-brief-switches))
4701	buffer)
4702    (or dirname (setq dirname default-directory))
4703    (setq dirname (expand-file-name dirname))
4704    (with-output-to-temp-buffer "*Directory*"
4705      (setq buffer standard-output)
4706      (buffer-disable-undo standard-output)
4707      (princ "Directory ")
4708      (princ dirname)
4709      (terpri)
4710      (save-excursion
4711	(set-buffer "*Directory*")
4712	(let ((wildcard (not (file-directory-p dirname))))
4713	  (insert-directory dirname switches wildcard (not wildcard)))))
4714    ;; Finishing with-output-to-temp-buffer seems to clobber default-directory.
4715    (with-current-buffer buffer
4716      (setq default-directory
4717	    (if (file-directory-p dirname)
4718		(file-name-as-directory dirname)
4719	      (file-name-directory dirname))))))
4720
4721(defun shell-quote-wildcard-pattern (pattern)
4722  "Quote characters special to the shell in PATTERN, leave wildcards alone.
4723
4724PATTERN is assumed to represent a file-name wildcard suitable for the
4725underlying filesystem.  For Unix and GNU/Linux, the characters from the
4726set [ \\t\\n;<>&|()#$] are quoted with a backslash; for DOS/Windows, all
4727the parts of the pattern which don't include wildcard characters are
4728quoted with double quotes.
4729Existing quote characters in PATTERN are left alone, so you can pass
4730PATTERN that already quotes some of the special characters."
4731  (save-match-data
4732    (cond
4733     ((memq system-type '(ms-dos windows-nt cygwin))
4734      ;; DOS/Windows don't allow `"' in file names.  So if the
4735      ;; argument has quotes, we can safely assume it is already
4736      ;; quoted by the caller.
4737      (if (or (string-match "[\"]" pattern)
4738	      ;; We quote [&()#$'] in case their shell is a port of a
4739	      ;; Unixy shell.  We quote [,=+] because stock DOS and
4740	      ;; Windows shells require that in some cases, such as
4741	      ;; passing arguments to batch files that use positional
4742	      ;; arguments like %1.
4743	      (not (string-match "[ \t;&()#$',=+]" pattern)))
4744	  pattern
4745	(let ((result "\"")
4746	      (beg 0)
4747	      end)
4748	  (while (string-match "[*?]+" pattern beg)
4749	    (setq end (match-beginning 0)
4750		  result (concat result (substring pattern beg end)
4751				 "\""
4752				 (substring pattern end (match-end 0))
4753				 "\"")
4754		  beg (match-end 0)))
4755	  (concat result (substring pattern beg) "\""))))
4756     (t
4757      (let ((beg 0))
4758	(while (string-match "[ \t\n;<>&|()#$]" pattern beg)
4759	  (setq pattern
4760		(concat (substring pattern 0 (match-beginning 0))
4761			"\\"
4762			(substring pattern (match-beginning 0)))
4763		beg (1+ (match-end 0)))))
4764      pattern))))
4765
4766
4767(defvar insert-directory-program "ls"
4768  "Absolute or relative name of the `ls' program used by `insert-directory'.")
4769
4770(defcustom directory-free-space-program "df"
4771  "Program to get the amount of free space on a file system.
4772We assume the output has the format of `df'.
4773The value of this variable must be just a command name or file name;
4774if you want to specify options, use `directory-free-space-args'.
4775
4776A value of nil disables this feature.
4777
4778If the function `file-system-info' is defined, it is always used in
4779preference to the program given by this variable."
4780  :type '(choice (string :tag "Program") (const :tag "None" nil))
4781  :group 'dired)
4782
4783(defcustom directory-free-space-args
4784  (if (eq system-type 'darwin) "-k" "-Pk")
4785  "Options to use when running `directory-free-space-program'."
4786  :type 'string
4787  :group 'dired)
4788
4789(defun get-free-disk-space (dir)
4790  "Return the amount of free space on directory DIR's file system.
4791The result is a string that gives the number of free 1KB blocks,
4792or nil if the system call or the program which retrieve the information
4793fail.  It returns also nil when DIR is a remote directory.
4794
4795This function calls `file-system-info' if it is available, or invokes the
4796program specified by `directory-free-space-program' if that is non-nil."
4797  (when (not (file-remote-p dir))
4798    ;; Try to find the number of free blocks.  Non-Posix systems don't
4799    ;; always have df, but might have an equivalent system call.
4800    (if (fboundp 'file-system-info)
4801	(let ((fsinfo (file-system-info dir)))
4802	  (if fsinfo
4803	      (format "%.0f" (/ (nth 2 fsinfo) 1024))))
4804      (save-match-data
4805	(with-temp-buffer
4806	  (when (and directory-free-space-program
4807		     (eq 0 (call-process directory-free-space-program
4808					 nil t nil
4809					 directory-free-space-args
4810					 dir)))
4811	    ;; Usual format is a header line followed by a line of
4812	    ;; numbers.
4813	    (goto-char (point-min))
4814	    (forward-line 1)
4815	    (if (not (eobp))
4816		(progn
4817		  ;; Move to the end of the "available blocks" number.
4818		  (skip-chars-forward "^ \t")
4819		  (forward-word 3)
4820		  ;; Copy it into AVAILABLE.
4821		  (let ((end (point)))
4822		    (forward-word -1)
4823		    (buffer-substring (point) end))))))))))
4824
4825;; The following expression replaces `dired-move-to-filename-regexp'.
4826(defvar directory-listing-before-filename-regexp
4827  (let* ((l "\\([A-Za-z]\\|[^\0-\177]\\)")
4828	 (l-or-quote "\\([A-Za-z']\\|[^\0-\177]\\)")
4829	 ;; In some locales, month abbreviations are as short as 2 letters,
4830	 ;; and they can be followed by ".".
4831	 ;; In Breton, a month name  can include a quote character.
4832	 (month (concat l-or-quote l-or-quote "+\\.?"))
4833	 (s " ")
4834	 (yyyy "[0-9][0-9][0-9][0-9]")
4835	 (dd "[ 0-3][0-9]")
4836	 (HH:MM "[ 0-2][0-9][:.][0-5][0-9]")
4837	 (seconds "[0-6][0-9]\\([.,][0-9]+\\)?")
4838	 (zone "[-+][0-2][0-9][0-5][0-9]")
4839	 (iso-mm-dd "[01][0-9]-[0-3][0-9]")
4840	 (iso-time (concat HH:MM "\\(:" seconds "\\( ?" zone "\\)?\\)?"))
4841	 (iso (concat "\\(\\(" yyyy "-\\)?" iso-mm-dd "[ T]" iso-time
4842		      "\\|" yyyy "-" iso-mm-dd "\\)"))
4843	 (western (concat "\\(" month s "+" dd "\\|" dd "\\.?" s month "\\)"
4844			  s "+"
4845			  "\\(" HH:MM "\\|" yyyy "\\)"))
4846	 (western-comma (concat month s "+" dd "," s "+" yyyy))
4847	 ;; Japanese MS-Windows ls-lisp has one-digit months, and
4848	 ;; omits the Kanji characters after month and day-of-month.
4849	 ;; On Mac OS X 10.3, the date format in East Asian locales is
4850	 ;; day-of-month digits followed by month digits.
4851	 (mm "[ 0-1]?[0-9]")
4852	 (east-asian
4853	  (concat "\\(" mm l "?" s dd l "?" s "+"
4854		  "\\|" dd s mm s "+" "\\)"
4855		  "\\(" HH:MM "\\|" yyyy l "?" "\\)")))
4856	 ;; The "[0-9]" below requires the previous column to end in a digit.
4857	 ;; This avoids recognizing `1 may 1997' as a date in the line:
4858	 ;; -r--r--r--   1 may      1997        1168 Oct 19 16:49 README
4859
4860	 ;; The "[BkKMGTPEZY]?" below supports "ls -alh" output.
4861	 ;; The ".*" below finds the last match if there are multiple matches.
4862	 ;; This avoids recognizing `jservice  10  1024' as a date in the line:
4863	 ;; drwxr-xr-x  3 jservice  10  1024 Jul  2  1997 esg-host
4864
4865         ;; vc dired listings provide the state or blanks between file
4866         ;; permissions and date.  The state is always surrounded by
4867         ;; parantheses:
4868         ;; -rw-r--r-- (modified) 2005-10-22 21:25 files.el
4869         ;; This is not supported yet.
4870    (concat ".*[0-9][BkKMGTPEZY]?" s
4871	    "\\(" western "\\|" western-comma "\\|" east-asian "\\|" iso "\\)"
4872	    s "+"))
4873  "Regular expression to match up to the file name in a directory listing.
4874The default value is designed to recognize dates and times
4875regardless of the language.")
4876
4877(defvar insert-directory-ls-version 'unknown)
4878
4879;; insert-directory
4880;; - must insert _exactly_one_line_ describing FILE if WILDCARD and
4881;;   FULL-DIRECTORY-P is nil.
4882;;   The single line of output must display FILE's name as it was
4883;;   given, namely, an absolute path name.
4884;; - must insert exactly one line for each file if WILDCARD or
4885;;   FULL-DIRECTORY-P is t, plus one optional "total" line
4886;;   before the file lines, plus optional text after the file lines.
4887;;   Lines are delimited by "\n", so filenames containing "\n" are not
4888;;   allowed.
4889;;   File lines should display the basename.
4890;; - must be consistent with
4891;;   - functions dired-move-to-filename, (these two define what a file line is)
4892;;   		 dired-move-to-end-of-filename,
4893;;		 dired-between-files, (shortcut for (not (dired-move-to-filename)))
4894;;   		 dired-insert-headerline
4895;;   		 dired-after-subdir-garbage (defines what a "total" line is)
4896;;   - variable dired-subdir-regexp
4897;; - may be passed "--dired" as the first argument in SWITCHES.
4898;;   Filename handlers might have to remove this switch if their
4899;;   "ls" command does not support it.
4900(defun insert-directory (file switches &optional wildcard full-directory-p)
4901  "Insert directory listing for FILE, formatted according to SWITCHES.
4902Leaves point after the inserted text.
4903SWITCHES may be a string of options, or a list of strings
4904representing individual options.
4905Optional third arg WILDCARD means treat FILE as shell wildcard.
4906Optional fourth arg FULL-DIRECTORY-P means file is a directory and
4907switches do not contain `d', so that a full listing is expected.
4908
4909This works by running a directory listing program
4910whose name is in the variable `insert-directory-program'.
4911If WILDCARD, it also runs the shell specified by `shell-file-name'.
4912
4913When SWITCHES contains the long `--dired' option, this function
4914treats it specially, for the sake of dired.  However, the
4915normally equivalent short `-D' option is just passed on to
4916`insert-directory-program', as any other option."
4917  ;; We need the directory in order to find the right handler.
4918  (let ((handler (find-file-name-handler (expand-file-name file)
4919					 'insert-directory)))
4920    (if handler
4921	(funcall handler 'insert-directory file switches
4922		 wildcard full-directory-p)
4923      (if (eq system-type 'vax-vms)
4924	  (vms-read-directory file switches (current-buffer))
4925	(let (result (beg (point)))
4926
4927	  ;; Read the actual directory using `insert-directory-program'.
4928	  ;; RESULT gets the status code.
4929	  (let* (;; We at first read by no-conversion, then after
4930		 ;; putting text property `dired-filename, decode one
4931		 ;; bunch by one to preserve that property.
4932		 (coding-system-for-read 'no-conversion)
4933		 ;; This is to control encoding the arguments in call-process.
4934		 (coding-system-for-write
4935		  (and enable-multibyte-characters
4936		       (or file-name-coding-system
4937			   default-file-name-coding-system))))
4938	    (setq result
4939		  (if wildcard
4940		      ;; Run ls in the directory part of the file pattern
4941		      ;; using the last component as argument.
4942		      (let ((default-directory
4943			      (if (file-name-absolute-p file)
4944				  (file-name-directory file)
4945				(file-name-directory (expand-file-name file))))
4946			    (pattern (file-name-nondirectory file)))
4947			(call-process
4948			 shell-file-name nil t nil
4949			 "-c"
4950			 (concat (if (memq system-type '(ms-dos windows-nt))
4951				     ""
4952				   "\\") ; Disregard Unix shell aliases!
4953				 insert-directory-program
4954				 " -d "
4955				 (if (stringp switches)
4956				     switches
4957				   (mapconcat 'identity switches " "))
4958				 " -- "
4959				 ;; Quote some characters that have
4960				 ;; special meanings in shells; but
4961				 ;; don't quote the wildcards--we want
4962				 ;; them to be special.  We also
4963				 ;; currently don't quote the quoting
4964				 ;; characters in case people want to
4965				 ;; use them explicitly to quote
4966				 ;; wildcard characters.
4967				 (shell-quote-wildcard-pattern pattern))))
4968		    ;; SunOS 4.1.3, SVr4 and others need the "." to list the
4969		    ;; directory if FILE is a symbolic link.
4970		    (apply 'call-process
4971			   insert-directory-program nil t nil
4972			   (append
4973			    (if (listp switches) switches
4974			      (unless (equal switches "")
4975				;; Split the switches at any spaces so we can
4976				;; pass separate options as separate args.
4977				(split-string switches)))
4978			    ;; Avoid lossage if FILE starts with `-'.
4979			    '("--")
4980			    (progn
4981			      (if (string-match "\\`~" file)
4982				  (setq file (expand-file-name file)))
4983			      (list
4984			       (if full-directory-p
4985				   (concat (file-name-as-directory file) ".")
4986				 file))))))))
4987
4988	  ;; If we got "//DIRED//" in the output, it means we got a real
4989	  ;; directory listing, even if `ls' returned nonzero.
4990	  ;; So ignore any errors.
4991	  (when (if (stringp switches)
4992		    (string-match "--dired\\>" switches)
4993		  (member "--dired" switches))
4994	    (save-excursion
4995	      (forward-line -2)
4996	      (when (looking-at "//SUBDIRED//")
4997		(forward-line -1))
4998	      (if (looking-at "//DIRED//")
4999		  (setq result 0))))
5000
5001	  (when (and (not (eq 0 result))
5002		     (eq insert-directory-ls-version 'unknown))
5003	    ;; The first time ls returns an error,
5004	    ;; find the version numbers of ls,
5005	    ;; and set insert-directory-ls-version
5006	    ;; to > if it is more than 5.2.1, < if it is less, nil if it
5007	    ;; is equal or if the info cannot be obtained.
5008	    ;; (That can mean it isn't GNU ls.)
5009	    (let ((version-out
5010		   (with-temp-buffer
5011		     (call-process "ls" nil t nil "--version")
5012		     (buffer-string))))
5013	      (if (string-match "ls (.*utils) \\([0-9.]*\\)$" version-out)
5014		  (let* ((version (match-string 1 version-out))
5015			 (split (split-string version "[.]"))
5016			 (numbers (mapcar 'string-to-number split))
5017			 (min '(5 2 1))
5018			 comparison)
5019		    (while (and (not comparison) (or numbers min))
5020		      (cond ((null min)
5021			     (setq comparison '>))
5022			    ((null numbers)
5023			     (setq comparison '<))
5024			    ((> (car numbers) (car min))
5025			     (setq comparison '>))
5026			    ((< (car numbers) (car min))
5027			     (setq comparison '<))
5028			    (t
5029			     (setq numbers (cdr numbers)
5030				   min (cdr min)))))
5031		    (setq insert-directory-ls-version (or comparison '=)))
5032		(setq insert-directory-ls-version nil))))
5033
5034	  ;; For GNU ls versions 5.2.2 and up, ignore minor errors.
5035	  (when (and (eq 1 result) (eq insert-directory-ls-version '>))
5036	    (setq result 0))
5037
5038	  ;; If `insert-directory-program' failed, signal an error.
5039	  (unless (eq 0 result)
5040	    ;; Delete the error message it may have output.
5041	    (delete-region beg (point))
5042	    ;; On non-Posix systems, we cannot open a directory, so
5043	    ;; don't even try, because that will always result in
5044	    ;; the ubiquitous "Access denied".  Instead, show the
5045	    ;; command line so the user can try to guess what went wrong.
5046	    (if (and (file-directory-p file)
5047		     (memq system-type '(ms-dos windows-nt)))
5048		(error
5049		 "Reading directory: \"%s %s -- %s\" exited with status %s"
5050		 insert-directory-program
5051		 (if (listp switches) (concat switches) switches)
5052		 file result)
5053	      ;; Unix.  Access the file to get a suitable error.
5054	      (access-file file "Reading directory")
5055	      (error "Listing directory failed but `access-file' worked")))
5056
5057	  (when (if (stringp switches)
5058		    (string-match "--dired\\>" switches)
5059		  (member "--dired" switches))
5060	    ;; The following overshoots by one line for an empty
5061	    ;; directory listed with "--dired", but without "-a"
5062	    ;; switch, where the ls output contains a
5063	    ;; "//DIRED-OPTIONS//" line, but no "//DIRED//" line.
5064	    ;; We take care of that case later.
5065	    (forward-line -2)
5066            (when (looking-at "//SUBDIRED//")
5067              (delete-region (point) (progn (forward-line 1) (point)))
5068              (forward-line -1))
5069	    (if (looking-at "//DIRED//")
5070		(let ((end (line-end-position))
5071		      (linebeg (point))
5072		      error-lines)
5073		  ;; Find all the lines that are error messages,
5074		  ;; and record the bounds of each one.
5075		  (goto-char beg)
5076		  (while (< (point) linebeg)
5077		    (or (eql (following-char) ?\s)
5078			(push (list (point) (line-end-position)) error-lines))
5079		    (forward-line 1))
5080		  (setq error-lines (nreverse error-lines))
5081		  ;; Now read the numeric positions of file names.
5082		  (goto-char linebeg)
5083		  (forward-word 1)
5084		  (forward-char 3)
5085		  (while (< (point) end)
5086		    (let ((start (insert-directory-adj-pos
5087				  (+ beg (read (current-buffer)))
5088				  error-lines))
5089			  (end (insert-directory-adj-pos
5090				(+ beg (read (current-buffer)))
5091				error-lines)))
5092		      (if (memq (char-after end) '(?\n ?\s))
5093			  ;; End is followed by \n or by " -> ".
5094			  (put-text-property start end 'dired-filename t)
5095			;; It seems that we can't trust ls's output as to
5096			;; byte positions of filenames.
5097			(put-text-property beg (point) 'dired-filename nil)
5098			(end-of-line))))
5099		  (goto-char end)
5100		  (beginning-of-line)
5101		  (delete-region (point) (progn (forward-line 1) (point))))
5102	      ;; Take care of the case where the ls output contains a
5103	      ;; "//DIRED-OPTIONS//"-line, but no "//DIRED//"-line
5104	      ;; and we went one line too far back (see above).
5105	      (forward-line 1))
5106	    (if (looking-at "//DIRED-OPTIONS//")
5107		(delete-region (point) (progn (forward-line 1) (point)))))
5108
5109	  ;; Now decode what read if necessary.
5110	  (let ((coding (or coding-system-for-read
5111			    file-name-coding-system
5112			    default-file-name-coding-system
5113			    'undecided))
5114		coding-no-eol
5115		val pos)
5116	    (when (and enable-multibyte-characters
5117		       (not (memq (coding-system-base coding)
5118				  '(raw-text no-conversion))))
5119	      ;; If no coding system is specified or detection is
5120	      ;; requested, detect the coding.
5121	      (if (eq (coding-system-base coding) 'undecided)
5122		  (setq coding (detect-coding-region beg (point) t)))
5123	      (if (not (eq (coding-system-base coding) 'undecided))
5124		  (save-restriction
5125		    (setq coding-no-eol
5126			  (coding-system-change-eol-conversion coding 'unix))
5127		    (narrow-to-region beg (point))
5128		    (goto-char (point-min))
5129		    (while (not (eobp))
5130		      (setq pos (point)
5131			    val (get-text-property (point) 'dired-filename))
5132		      (goto-char (next-single-property-change
5133				  (point) 'dired-filename nil (point-max)))
5134		      ;; Force no eol conversion on a file name, so
5135		      ;; that CR is preserved.
5136		      (decode-coding-region pos (point)
5137					    (if val coding-no-eol coding))
5138		      (if val
5139			  (put-text-property pos (point)
5140					     'dired-filename t)))))))
5141
5142	  (if full-directory-p
5143	      ;; Try to insert the amount of free space.
5144	      (save-excursion
5145		(goto-char beg)
5146		;; First find the line to put it on.
5147		(when (re-search-forward "^ *\\(total\\)" nil t)
5148		  (let ((available (get-free-disk-space ".")))
5149		    (when available
5150		      ;; Replace "total" with "used", to avoid confusion.
5151		      (replace-match "total used in directory" nil nil nil 1)
5152		      (end-of-line)
5153		      (insert " available " available)))))))))))
5154
5155(defun insert-directory-adj-pos (pos error-lines)
5156  "Convert `ls --dired' file name position value POS to a buffer position.
5157File name position values returned in ls --dired output
5158count only stdout; they don't count the error messages sent to stderr.
5159So this function converts to them to real buffer positions.
5160ERROR-LINES is a list of buffer positions of error message lines,
5161of the form (START END)."
5162  (while (and error-lines (< (caar error-lines) pos))
5163    (setq pos (+ pos (- (nth 1 (car error-lines)) (nth 0 (car error-lines)))))
5164    (pop error-lines))
5165  pos)
5166
5167(defun insert-directory-safely (file switches
5168				     &optional wildcard full-directory-p)
5169  "Insert directory listing for FILE, formatted according to SWITCHES.
5170
5171Like `insert-directory', but if FILE does not exist, it inserts a
5172message to that effect instead of signaling an error."
5173  (if (file-exists-p file)
5174      (insert-directory file switches wildcard full-directory-p)
5175    ;; Simulate the message printed by `ls'.
5176    (insert (format "%s: No such file or directory\n" file))))
5177
5178(defvar kill-emacs-query-functions nil
5179  "Functions to call with no arguments to query about killing Emacs.
5180If any of these functions returns nil, killing Emacs is cancelled.
5181`save-buffers-kill-emacs' (\\[save-buffers-kill-emacs]) calls these functions,
5182but `kill-emacs', the low level primitive, does not.
5183See also `kill-emacs-hook'.")
5184
5185(defcustom confirm-kill-emacs nil
5186  "How to ask for confirmation when leaving Emacs.
5187If nil, the default, don't ask at all.  If the value is non-nil, it should
5188be a predicate function such as `yes-or-no-p'."
5189  :type '(choice (const :tag "Ask with yes-or-no-p" yes-or-no-p)
5190		 (const :tag "Ask with y-or-n-p" y-or-n-p)
5191		 (const :tag "Don't confirm" nil))
5192  :group 'convenience
5193  :version "21.1")
5194
5195(defun save-buffers-kill-emacs (&optional arg)
5196  "Offer to save each buffer, then kill this Emacs process.
5197With prefix arg, silently save all file-visiting buffers, then kill."
5198  (interactive "P")
5199  (save-some-buffers arg t)
5200  (and (or (not (memq t (mapcar (function
5201				  (lambda (buf) (and (buffer-file-name buf)
5202						     (buffer-modified-p buf))))
5203				(buffer-list))))
5204	   (yes-or-no-p "Modified buffers exist; exit anyway? "))
5205       (or (not (fboundp 'process-list))
5206	   ;; process-list is not defined on VMS.
5207	   (let ((processes (process-list))
5208		 active)
5209	     (while processes
5210	       (and (memq (process-status (car processes)) '(run stop open listen))
5211		    (process-query-on-exit-flag (car processes))
5212		    (setq active t))
5213	       (setq processes (cdr processes)))
5214	     (or (not active)
5215		 (list-processes t)
5216		 (yes-or-no-p "Active processes exist; kill them and exit anyway? "))))
5217       ;; Query the user for other things, perhaps.
5218       (run-hook-with-args-until-failure 'kill-emacs-query-functions)
5219       (or (null confirm-kill-emacs)
5220	   (funcall confirm-kill-emacs "Really exit Emacs? "))
5221       (kill-emacs)))
5222
5223;; We use /: as a prefix to "quote" a file name
5224;; so that magic file name handlers will not apply to it.
5225
5226(setq file-name-handler-alist
5227      (cons '("\\`/:" . file-name-non-special)
5228	    file-name-handler-alist))
5229
5230;; We depend on being the last handler on the list,
5231;; so that anything else which does need handling
5232;; has been handled already.
5233;; So it is safe for us to inhibit *all* magic file name handlers.
5234
5235(defun file-name-non-special (operation &rest arguments)
5236  (let ((file-name-handler-alist nil)
5237	(default-directory
5238	  (if (eq operation 'insert-directory)
5239	      (directory-file-name
5240	       (expand-file-name
5241		(unhandled-file-name-directory default-directory)))
5242	    default-directory))
5243	;; Get a list of the indices of the args which are file names.
5244	(file-arg-indices
5245	 (cdr (or (assq operation
5246			;; The first six are special because they
5247			;; return a file name.  We want to include the /:
5248			;; in the return value.
5249			;; So just avoid stripping it in the first place.
5250			'((expand-file-name . nil)
5251			  (file-name-directory . nil)
5252			  (file-name-as-directory . nil)
5253			  (directory-file-name . nil)
5254			  (file-name-sans-versions . nil)
5255			  (find-backup-file-name . nil)
5256			  ;; `identity' means just return the first arg
5257			  ;; not stripped of its quoting.
5258			  (substitute-in-file-name identity)
5259			  ;; `add' means add "/:" to the result.
5260			  (file-truename add 0)
5261			  ;; `quote' means add "/:" to buffer-file-name.
5262			  (insert-file-contents quote 0)
5263			  ;; `unquote-then-quote' means set buffer-file-name
5264			  ;; temporarily to unquoted filename.
5265			  (verify-visited-file-modtime unquote-then-quote)
5266			  ;; List the arguments which are filenames.
5267			  (file-name-completion 1)
5268			  (file-name-all-completions 1)
5269			  (write-region 2 5)
5270			  (rename-file 0 1)
5271			  (copy-file 0 1)
5272			  (make-symbolic-link 0 1)
5273			  (add-name-to-file 0 1)))
5274		  ;; For all other operations, treat the first argument only
5275		  ;; as the file name.
5276		  '(nil 0))))
5277	method
5278	;; Copy ARGUMENTS so we can replace elements in it.
5279	(arguments (copy-sequence arguments)))
5280    (if (symbolp (car file-arg-indices))
5281	(setq method (pop file-arg-indices)))
5282    ;; Strip off the /: from the file names that have it.
5283    (save-match-data
5284      (while (consp file-arg-indices)
5285	(let ((pair (nthcdr (car file-arg-indices) arguments)))
5286	  (and (car pair)
5287	       (string-match "\\`/:" (car pair))
5288	       (setcar pair
5289		       (if (= (length (car pair)) 2)
5290			   "/"
5291			 (substring (car pair) 2)))))
5292	(setq file-arg-indices (cdr file-arg-indices))))
5293    (cond ((eq method 'identity)
5294	   (car arguments))
5295	  ((eq method 'add)
5296	   (concat "/:" (apply operation arguments)))
5297	  ((eq method 'quote)
5298	   (unwind-protect
5299	       (apply operation arguments)
5300	     (setq buffer-file-name (concat "/:" buffer-file-name))))
5301	  ((eq method 'unquote-then-quote)
5302	   (let (res)
5303	     (setq buffer-file-name (substring buffer-file-name 2))
5304	     (setq res (apply operation arguments))
5305	     (setq buffer-file-name (concat "/:" buffer-file-name))
5306	     res))
5307	  (t
5308	   (apply operation arguments)))))
5309
5310(define-key ctl-x-map "\C-f" 'find-file)
5311(define-key ctl-x-map "\C-r" 'find-file-read-only)
5312(define-key ctl-x-map "\C-v" 'find-alternate-file)
5313(define-key ctl-x-map "\C-s" 'save-buffer)
5314(define-key ctl-x-map "s" 'save-some-buffers)
5315(define-key ctl-x-map "\C-w" 'write-file)
5316(define-key ctl-x-map "i" 'insert-file)
5317(define-key esc-map "~" 'not-modified)
5318(define-key ctl-x-map "\C-d" 'list-directory)
5319(define-key ctl-x-map "\C-c" 'save-buffers-kill-emacs)
5320(define-key ctl-x-map "\C-q" 'toggle-read-only)
5321
5322(define-key ctl-x-4-map "f" 'find-file-other-window)
5323(define-key ctl-x-4-map "r" 'find-file-read-only-other-window)
5324(define-key ctl-x-4-map "\C-f" 'find-file-other-window)
5325(define-key ctl-x-4-map "b" 'switch-to-buffer-other-window)
5326(define-key ctl-x-4-map "\C-o" 'display-buffer)
5327
5328(define-key ctl-x-5-map "b" 'switch-to-buffer-other-frame)
5329(define-key ctl-x-5-map "f" 'find-file-other-frame)
5330(define-key ctl-x-5-map "\C-f" 'find-file-other-frame)
5331(define-key ctl-x-5-map "r" 'find-file-read-only-other-frame)
5332(define-key ctl-x-5-map "\C-o" 'display-buffer-other-frame)
5333
5334;; arch-tag: bc68d3ea-19ca-468b-aac6-3a4a7766101f
5335;;; files.el ends here
5336