files.el 53.1 KB
Newer Older
Roland McGrath's avatar
Roland McGrath committed
1
;; File input and output commands for Emacs
Jim Blandy's avatar
Jim Blandy committed
2
;; Copyright (C) 1985, 1986, 1987, 1992 Free Software Foundation, Inc.
Roland McGrath's avatar
Roland McGrath committed
3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149

;; This file is part of GNU Emacs.

;; GNU Emacs is free software; you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation; either version 1, or (at your option)
;; any later version.

;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;; GNU General Public License for more details.

;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs; see the file COPYING.  If not, write to
;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.

(defconst delete-auto-save-files t
  "*Non-nil means delete a buffer's auto-save file when the buffer is saved.")

(defconst directory-abbrev-alist
  nil
  "*Alist of abbreviations for file directories.
A list of elements of the form (FROM . TO), each meaning to replace
FROM with TO when it appears in a directory name.  This replacement is
done when setting up the default directory of a newly visited file.
*Every* FROM string should start with `^'.

Use this feature when you have directories which you normally refer to
via absolute symbolic links.  Make TO the name of the link, and FROM
the name it is linked to.")

;;; Turn off backup files on VMS since it has version numbers.
(defconst make-backup-files (not (eq system-type 'vax-vms))
  "*Create a backup of each file when it is saved for the first time.
This can be done by renaming the file or by copying.

Renaming means that Emacs renames the existing file so that it is a
backup file, then writes the buffer into a new file.  Any other names
that the old file had will now refer to the backup file.  The new file
is owned by you and its group is defaulted.

Copying means that Emacs copies the existing file into the backup
file, then writes the buffer on top of the existing file.  Any other
names that the old file had will now refer to the new (edited) file.
The file's owner and group are unchanged.

The choice of renaming or copying is controlled by the variables
`backup-by-copying', `backup-by-copying-when-linked' and
`backup-by-copying-when-mismatch'.")

;; Do this so that local variables based on the file name
;; are not overridden by the major mode.
(defvar backup-inhibited nil
  "Non-nil means don't make a backup file for this buffer.")
(put 'backup-inhibited 'permanent-local t)

(defconst backup-by-copying nil
 "*Non-nil means always use copying to create backup files.
See documentation of variable `make-backup-files'.")

(defconst backup-by-copying-when-linked nil
 "*Non-nil means use copying to create backups for files with multiple names.
This causes the alternate names to refer to the latest version as edited.
This variable is relevant only if `backup-by-copying' is nil.")

(defconst backup-by-copying-when-mismatch nil
  "*Non-nil means create backups by copying if this preserves owner or group.
Renaming may still be used (subject to control of other variables)
when it would not result in changing the owner or group of the file;
that is, for files which are owned by you and whose group matches
the default for a new file created there by you.
This variable is relevant only if `backup-by-copying' is nil.")

(defvar backup-enable-predicate
  '(lambda (name)
     (or (< (length name) 5)
	 (not (string-equal "/tmp/" (substring name 0 5)))))
  "Predicate that looks at a file name and decides whether to make backups.
Called with an absolute file name as argument, it returns t to enable backup.")

(defconst buffer-offer-save nil
  "*Non-nil in a buffer means offer to save the buffer on exit
even if the buffer is not visiting a file.
Automatically local in all buffers.")
(make-variable-buffer-local 'buffer-offer-save)

(defconst file-precious-flag nil
  "*Non-nil means protect against I/O errors while saving files.
Some modes set this non-nil in particular buffers.")

(defvar version-control nil
  "*Control use of version numbers for backup files.
t means make numeric backup versions unconditionally.
nil means make them for files that have some already.
never means do not make them.")

(defvar dired-kept-versions 2
  "*When cleaning directory, number of versions to keep.")

(defvar trim-versions-without-asking nil
  "*If true, deletes excess backup versions silently.
Otherwise asks confirmation.")

(defvar kept-old-versions 2
  "*Number of oldest versions to keep when a new numbered backup is made.")

(defvar kept-new-versions 2
  "*Number of newest versions to keep when a new numbered backup is made.
Includes the new backup.  Must be > 0")

(defconst require-final-newline nil
  "*Value of t says silently ensure a file ends in a newline when it is saved.
Non-nil but not t says ask user whether to add a newline when there isn't one.
nil means don't add newlines.")

(defconst auto-save-default t
  "*Non-nil says by default do auto-saving of every file-visiting buffer.")

(defconst auto-save-visited-file-name nil
  "*Non-nil says auto-save a buffer in the file it is visiting, when practical.
Normally auto-save files are written under other names.")

(defconst save-abbrevs nil
  "*Non-nil means save word abbrevs too when files are saved.
Loading an abbrev file sets this to t.")

(defconst find-file-run-dired t
  "*Non-nil says run dired if find-file is given the name of a directory.")

(put 'find-file-not-found-hooks 'permanent-local t)
(defvar find-file-not-found-hooks nil
  "List of functions to be called for `find-file' on nonexistent file.
These functions are called as soon as the error is detected.
`buffer-file-name' is already set up.
The functions are called in the order given until one of them returns non-nil.")

(put 'find-file-hooks 'permanent-local t)
(defvar find-file-hooks nil
  "List of functions to be called after a buffer is loaded from a file.
The buffer's local variables (if any) will have been processed before the
functions are called.")

(put 'write-file-hooks 'permanent-local t)
(defvar write-file-hooks nil
  "List of functions to be called before writing out a buffer to a file.
If one of them returns non-nil, the file is considered already written
Jim Blandy's avatar
Jim Blandy committed
150 151 152 153 154 155 156 157 158 159 160 161 162
and the rest are not called.
These hooks are considered to pertain to the visited file.
So this list is cleared if you change the visited file name.
See also `write-contents-hooks'.")

(defvar write-contents-hooks nil
  "List of functions to be called before writing out a buffer to a file.
If one of them returns non-nil, the file is considered already written
and the rest are not called.
These hooks are considered to pertain to the buffer's contents,
not to the particular visited file; thus, `set-visited-file-name' does
not clear this variable, but changing the major mode does clear it.
See also `write-file-hooks'.")
Roland McGrath's avatar
Roland McGrath committed
163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200

(defconst enable-local-variables t
  "*Control use of local-variables lists in files you visit.
The value can be t, nil or something else.
A value of t means local-variables lists are obeyed;
nil means they are ignored; anything else means query.

The command \\[normal-mode] always obeys local-variables lists
and ignores this variable.")

(defconst ignore-local-eval nil
  "*Non-nil means ignore the \"variable\" `eval' in a file's local variables.
This applies when the local-variables list is scanned automatically
after you find a file.  If you explicitly request such a scan with
\\[normal-mode], there is no query, regardless of this variable.")

;; Avoid losing in versions where CLASH_DETECTION is disabled.
(or (fboundp 'lock-buffer)
    (fset 'lock-buffer 'ignore))
(or (fboundp 'unlock-buffer)
    (fset 'unlock-buffer 'ignore))

(defun pwd ()
  "Show the current default directory."
  (interactive nil)
  (message "Directory %s" default-directory))

(defun cd (dir)
  "Make DIR become the current buffer's default directory."
  (interactive "DChange default directory: ")
  (setq dir (expand-file-name dir))
  (if (not (eq system-type 'vax-vms))
      (setq dir (file-name-as-directory dir)))
  (if (not (file-directory-p dir))
      (error "%s is not a directory" dir)
    (if (file-executable-p dir)
	(setq default-directory dir)
      (error "Cannot cd to %s:  Permission denied" dir)))
Jim Blandy's avatar
Jim Blandy committed
201 202 203 204
  ;; We used to call pwd at this point.  That's not terribly helpful
  ;; when we're invoking cd interactively, and the new cmushell-based
  ;; shell has its own (better) facilities for this.
)
Roland McGrath's avatar
Roland McGrath committed
205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222

(defun load-file (file)
  "Load the Lisp file named FILE."
  (interactive "fLoad file: ")
  (load (expand-file-name file) nil nil t))

(defun load-library (library)
  "Load the library named LIBRARY.
This is an interface to the function `load'."
  (interactive "sLoad library: ")
  (load library))

(defun switch-to-buffer-other-window (buffer)
  "Select buffer BUFFER in another window."
  (interactive "BSwitch to buffer in other window: ")
  (let ((pop-up-windows t))
    (pop-to-buffer buffer t)))

Jim Blandy's avatar
Jim Blandy committed
223 224 225 226 227 228
(defun switch-to-buffer-other-screen (buffer)
  "Switch to buffer BUFFER in another screen."
  (interactive "BSwitch to buffer in other screen: ")
  (let ((pop-up-screens t))
    (pop-to-buffer buffer)))

Roland McGrath's avatar
Roland McGrath committed
229 230 231 232 233 234 235 236 237 238 239 240 241 242
(defun find-file (filename)
  "Edit file FILENAME.
Switch to a buffer visiting file FILENAME,
creating one if none already exists."
  (interactive "FFind file: ")
  (switch-to-buffer (find-file-noselect filename)))

(defun find-file-other-window (filename)
  "Edit file FILENAME, in another window.
May create a new window, or reuse an existing one.
See the function `display-buffer'."
  (interactive "FFind file in other window: ")
  (switch-to-buffer-other-window (find-file-noselect filename)))

Jim Blandy's avatar
Jim Blandy committed
243 244 245 246 247 248 249
(defun find-file-other-screen (filename)
  "Edit file FILENAME, in another screen.
May create a new screen, or reuse an existing one.
See the function `display-buffer'."
  (interactive "FFind file in other screen: ")
  (switch-to-buffer-other-screen (find-file-noselect filename)))

Roland McGrath's avatar
Roland McGrath committed
250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265
(defun find-file-read-only (filename)
  "Edit file FILENAME but don't allow changes.
Like \\[find-file] but marks buffer as read-only.
Use \\[toggle-read-only] to permit editing."
  (interactive "fFind file read-only: ")
  (find-file filename)
  (setq buffer-read-only t))

(defun find-file-read-only-other-window (filename)
  "Edit file FILENAME in another window but don't allow changes.
Like \\[find-file-other-window] but marks buffer as read-only.
Use \\[toggle-read-only] to permit editing."
  (interactive "fFind file read-only other window: ")
  (find-file filename)
  (setq buffer-read-only t))

Jim Blandy's avatar
Jim Blandy committed
266 267 268 269 270 271 272 273
(defun find-file-read-only-other-screen (filename)
  "Edit file FILENAME in another screen but don't allow changes.
Like \\[find-file-other-screen] but marks buffer as read-only.
Use \\[toggle-read-only] to permit editing."
  (interactive "fFind file read-only other screen: ")
  (find-file-other-screen filename)
  (setq buffer-read-only t))

Roland McGrath's avatar
Roland McGrath committed
274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315
(defun find-alternate-file (filename)
  "Find file FILENAME, select its buffer, kill previous buffer.
If the current buffer now contains an empty file that you just visited
\(presumably by mistake), use this command to visit the file you really want."
  (interactive
   (let ((file buffer-file-name)
	 (file-name nil)
	 (file-dir nil))
     (and file
	  (setq file-name (file-name-nondirectory file)
		file-dir (file-name-directory file)))
     (list (read-file-name "Find alternate file: " file-dir nil nil file-name))))
  (and (buffer-modified-p)
       ;; (not buffer-read-only)
       (not (yes-or-no-p (format "Buffer %s is modified; kill anyway? "
				 (buffer-name))))
       (error "Aborted"))
  (let ((obuf (current-buffer))
	(ofile buffer-file-name)
	(oname (buffer-name)))
    (rename-buffer " **lose**")
    (setq buffer-file-name nil)
    (unwind-protect
	(progn
	  (unlock-buffer)
	  (find-file filename))
      (cond ((eq obuf (current-buffer))
	     (setq buffer-file-name ofile)
	     (lock-buffer)
	     (rename-buffer oname))))
    (or (eq (current-buffer) obuf)
	(kill-buffer obuf))))

(defun create-file-buffer (filename)
  "Create a suitably named buffer for visiting FILENAME, and return it.
FILENAME (sans directory) is used unchanged if that name is free;
otherwise a string <2> or <3> or ... is appended to get an unused name."
  (let ((lastname (file-name-nondirectory filename)))
    (if (string= lastname "")
	(setq lastname filename))
    (generate-new-buffer lastname)))

Jim Blandy's avatar
Jim Blandy committed
316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335
(defun generate-new-buffer (name)
  "Create and return a buffer with a name based on NAME.
Choose the buffer's name using generate-new-buffer-name."
  (get-buffer-create (generate-new-buffer-name name)))

(defun abbreviate-file-name (filename)
  "Return a version of FILENAME shortened using directory-abbrev-alist.
This also substitutes \"~\" for the user's home directory.
See \\[describe-variable] directory-abbrev-alist RET for more information."
  (let ((tail directory-abbrev-alist))
    (while tail
      (if (string-match (car (car tail)) filename)
	  (setq filename
		(concat (cdr (car tail)) (substring filename (match-end 0)))))
      (setq tail (cdr tail)))
    (if (string-match (concat "^" (expand-file-name "~")) filename)
	(setq filename
	      (concat "~" (substring filename (match-end 0)))))
    filename))

Roland McGrath's avatar
Roland McGrath committed
336 337 338 339 340 341 342 343 344 345 346
(defun find-file-noselect (filename &optional nowarn)
  "Read file FILENAME into a buffer and return the buffer.
If a buffer exists visiting FILENAME, return that one, but
verify that the file has not changed since visited or saved.
The buffer is not selected, just returned to the caller."
  (setq filename (expand-file-name filename))
  ;; Get rid of the prefixes added by the automounter.
  (if (and (string-match "^/tmp_mnt/" filename)
	   (file-exists-p (file-name-directory
			   (substring filename (1- (match-end 0))))))
      (setq filename (substring filename (1- (match-end 0)))))
Jim Blandy's avatar
Jim Blandy committed
347
  (setq filename (abbreviate-file-name filename))
Roland McGrath's avatar
Roland McGrath committed
348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425
  (if (file-directory-p filename)
      (if find-file-run-dired
	  (dired-noselect filename)
	(error "%s is a directory." filename))
    (let ((buf (get-file-buffer filename))
	  error)
      (if buf
	  (or nowarn
	      (verify-visited-file-modtime buf)
	      (cond ((not (file-exists-p filename))
		     (error "File %s no longer exists!" filename))
		    ((yes-or-no-p
		      (format
		       (if (buffer-modified-p buf)
    "File %s changed on disk.  Discard your edits? "
    "File %s changed on disk.  Read the new version? ")
		       (file-name-nondirectory filename)))
		     (save-excursion
		       (set-buffer buf)
		       (revert-buffer t t)))))
	(save-excursion
	  (let* ((link-name (car (file-attributes filename)))
		 (linked-buf (and (stringp link-name)
				  (get-file-buffer link-name))))
	    (if (bufferp linked-buf)
		(message "Symbolic link to file in buffer %s"
			 (buffer-name linked-buf))))
	  (setq buf (create-file-buffer filename))
	  (set-buffer buf)
	  (erase-buffer)
	  (condition-case ()
	      (insert-file-contents filename t)
	    (file-error
	     (setq error t)
	     ;; Run find-file-not-found-hooks until one returns non-nil.
	     (let ((hooks find-file-not-found-hooks))
	       (while (and hooks
			   (not (funcall (car hooks))))
		 (setq hooks (cdr hooks))))))
	  ;; Set buffer's default directory to that of the file.
	  (setq default-directory (file-name-directory filename))
	  ;; Turn off backup files for certain file names.  Since
	  ;; this is a permanent local, the major mode won't eliminate it.
	  (and (not (funcall backup-enable-predicate buffer-file-name))
	       (progn
		 (make-local-variable 'backup-inhibited)
		 (setq backup-inhibited t)))
	  (after-find-file error (not nowarn))))
      buf)))

(defun after-find-file (&optional error warn)
  "Called after finding a file and by the default revert function.
Sets buffer mode, parses local variables.
Optional args ERROR and WARN: ERROR non-nil means there was an
error in reading the file.  WARN non-nil means warn if there
exists an auto-save file more recent than the visited file.
Finishes by calling the functions in `find-file-hooks'."
  (setq buffer-read-only (not (file-writable-p buffer-file-name)))
  (if noninteractive
      nil
    (let* (not-serious
	   (msg
	    (cond ((and error (file-attributes buffer-file-name))
		   (setq buffer-read-only t)
		   "File exists, but is read-protected.")
		  ((not buffer-read-only)
		   (if (and warn
			    (file-newer-than-file-p (make-auto-save-file-name)
						    buffer-file-name))
		       "Auto save file is newer; consider M-x recover-file"
		     (setq not-serious t)
		     (if error "(New file)" nil)))
		  ((not error)
		   (setq not-serious t)
		   "Note: file is write protected")
		  ((file-attributes (directory-file-name default-directory))
		   "File not found and directory write-protected")
		  (t
Jim Blandy's avatar
Jim Blandy committed
426 427 428 429 430 431 432 433 434 435 436 437 438
		   ;; If the directory the buffer is in doesn't exist,
		   ;; offer to create it.  It's better to do this now
		   ;; than when we save the buffer, because we want
		   ;; autosaving to work.
		   (setq buffer-read-only nil)
		   (or (file-exists-p (file-name-directory buffer-file-name))
		       (if (yes-or-no-p
			    (format
			     "The directory containing %s does not exist.  Create? "
			     (abbreviate-file-name buffer-file-name)))
			   (make-directory-path
			    (file-name-directory buffer-file-name))))
		   nil))))
Roland McGrath's avatar
Roland McGrath committed
439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464
      (if msg
	  (progn
	    (message msg)
	    (or not-serious (sit-for 1 nil t)))))
    (if auto-save-default
	(auto-save-mode t)))
  (normal-mode t)
  (mapcar 'funcall find-file-hooks))

(defun normal-mode (&optional find-file)
  "Choose the major mode for this buffer automatically.
Also sets up any specified local variables of the file.
Uses the visited file name, the -*- line, and the local variables spec.

This function is called automatically from `find-file'.  In that case,
we may set up specified local variables depending on the value of
`enable-local-variables': if it is t, we do; if it is nil, we don't;
otherwise, we query.  `enable-local-variables' is ignored if you
run `normal-mode' explicitly."
  (interactive)
  (or find-file (funcall (or default-major-mode 'fundamental-mode)))
  (condition-case err
      (set-auto-mode)
    (error (message "File mode specification error: %s"
		    (prin1-to-string err))))
  (condition-case err
Jim Blandy's avatar
Jim Blandy committed
465 466 467
      (let ((enable-local-variables (or (not find-file)
					enable-local-variables)))
	(hack-local-variables))
Roland McGrath's avatar
Roland McGrath committed
468 469 470
    (error (message "File local-variables error: %s"
		    (prin1-to-string err)))))

Jim Blandy's avatar
Jim Blandy committed
471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522
(defvar auto-mode-alist (mapcar 'purecopy
				'(("\\.text\\'" . text-mode)
				  ("\\.c\\'" . c-mode)
				  ("\\.h\\'" . c-mode)
				  ("\\.tex\\'" . TeX-mode)
				  ("\\.ltx\\'" . LaTeX-mode)
				  ("\\.el\\'" . emacs-lisp-mode)
				  ("\\.mm\\'" . nroff-mode)
				  ("\\.me\\'" . nroff-mode)
				  ("\\.[12345678]\\'" . nroff-mode)
				  ("\\.scm\\'" . scheme-mode)
				  ("\\.l\\'" . lisp-mode)
				  ("\\.lisp\\'" . lisp-mode)
				  ("\\.f\\'" . fortran-mode)
				  ("\\.for\\'" . fortran-mode)
				  ("\\.mss\\'" . scribe-mode)
				  ("\\.pl\\'" . prolog-mode)
				  ("\\.cc\\'" . c++-mode)
				  ("\\.C\\'" . c++-mode)
;;; Less common extensions come here
;;; so more common ones above are found faster.
				  ("\\.s\\'" . asm-mode)
				  ("ChangeLog\\'" . change-log-mode)
				  ("\\$CHANGE_LOG\\$\\.TXT" . change-log-mode)
				  ("\\.TeX\\'" . TeX-mode)
				  ("\\.sty\\'" . LaTeX-mode)
				  ("\\.bbl\\'" . LaTeX-mode)
				  ("\\.bib\\'" . bibtex-mode)
				  ("\\.article\\'" . text-mode)
				  ("\\.letter\\'" . text-mode)
				  ("\\.texinfo\\'" . texinfo-mode)
				  ("\\.lsp\\'" . lisp-mode)
				  ("\\.awk\\'" . awk-mode)
				  ("\\.prolog\\'" . prolog-mode)
				  ;; Mailer puts message to be edited in
				  ;; /tmp/Re.... or Message
				  ("^/tmp/Re" . text-mode)
				  ("/Message[0-9]*\\'" . text-mode)
				  ;; some news reader is reported to use this
				  ("^/tmp/fol/" . text-mode)
				  ("\\.y\\'" . c-mode)
				  ("\\.oak\\'" . scheme-mode)
				  ("\\.scm.[0-9]*\\'" . scheme-mode)
				  ;; .emacs following a directory delimiter
				  ;; in either Unix or VMS syntax.
				  ("[]>:/]\\..*emacs\\'" . emacs-lisp-mode)
				  ("\\.ml\\'" . lisp-mode)))
  "\
Alist of filename patterns vs corresponding major mode functions.
Each element looks like (REGEXP . FUNCTION).
Visiting a file whose name matches REGEXP causes FUNCTION to be called.")

Roland McGrath's avatar
Roland McGrath committed
523 524
(defun set-auto-mode ()
  "Select major mode appropriate for current buffer.
Jim Blandy's avatar
Jim Blandy committed
525 526 527 528 529 530 531
This checks for a -*- mode tag in the buffer's text, or
compares the filename against the entries in auto-mode-alist.  It does
not check for the \"mode:\" local variable in the Local Variables
section of the file; for that, use `hack-local-variables'.

If enable-local-variables is nil, this function will not check for a
-*- mode tag."
Roland McGrath's avatar
Roland McGrath committed
532 533 534 535 536
  ;; Look for -*-MODENAME-*- or -*- ... mode: MODENAME; ... -*-
  (let (beg end mode)
    (save-excursion
      (goto-char (point-min))
      (skip-chars-forward " \t\n")
Jim Blandy's avatar
Jim Blandy committed
537 538
      (if (and enable-local-variables
	       (search-forward "-*-" (save-excursion (end-of-line) (point)) t)
Roland McGrath's avatar
Roland McGrath committed
539 540 541
	       (progn
		 (skip-chars-forward " \t")
		 (setq beg (point))
Jim Blandy's avatar
Jim Blandy committed
542 543 544
		 (search-forward "-*-"
				 (save-excursion (end-of-line) (point))
				 t))
Roland McGrath's avatar
Roland McGrath committed
545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576
	       (progn
		 (forward-char -3)
		 (skip-chars-backward " \t")
		 (setq end (point))
		 (goto-char beg)
		 (if (search-forward ":" end t)
		     (progn
		       (goto-char beg)
		       (if (let ((case-fold-search t))
			     (search-forward "mode:" end t))
			   (progn
			     (skip-chars-forward " \t")
			     (setq beg (point))
			     (if (search-forward ";" end t)
				 (forward-char -1)
			       (goto-char end))
			     (skip-chars-backward " \t")
			     (setq mode (buffer-substring beg (point))))))
		   (setq mode (buffer-substring beg end)))))
	  (setq mode (intern (concat (downcase mode) "-mode")))
	(let ((alist auto-mode-alist)
	      (name buffer-file-name))
	  (let ((case-fold-search (eq system-type 'vax-vms)))
	    ;; Remove backup-suffixes from file name.
	    (setq name (file-name-sans-versions name))
	    ;; Find first matching alist entry.
	    (while (and (not mode) alist)
	      (if (string-match (car (car alist)) name)
		  (setq mode (cdr (car alist))))
	      (setq alist (cdr alist)))))))
    (if mode (funcall mode))))

Jim Blandy's avatar
Jim Blandy committed
577
(defun hack-local-variables ()
Roland McGrath's avatar
Roland McGrath committed
578 579 580 581 582 583 584 585
  "Parse (and bind or evaluate as appropriate) any local variables
for current buffer."
  ;; Look for "Local variables:" line in last page.
  (save-excursion
    (goto-char (point-max))
    (search-backward "\n\^L" (max (- (point-max) 3000) (point-min)) 'move)
    (if (let ((case-fold-search t))
	  (and (search-forward "Local Variables:" nil t)
Jim Blandy's avatar
Jim Blandy committed
586
	       (or (eq enable-local-variables t)
Roland McGrath's avatar
Roland McGrath committed
587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607
		   (and enable-local-variables
			(save-window-excursion
			  (switch-to-buffer (current-buffer))
			  (save-excursion
			    (beginning-of-line)
			    (set-window-start (selected-window) (point)))
			  (y-or-n-p (format "Set local variables as specified at end of %s? "
					    (file-name-nondirectory buffer-file-name))))))))
	(let ((continue t)
	      prefix prefixlen suffix beg)
	  ;; The prefix is what comes before "local variables:" in its line.
	  ;; The suffix is what comes after "local variables:" in its line.
	  (skip-chars-forward " \t")
	  (or (eolp)
	      (setq suffix (buffer-substring (point)
					     (progn (end-of-line) (point)))))
	  (goto-char (match-beginning 0))
	  (or (bolp)
	      (setq prefix
		    (buffer-substring (point)
				      (progn (beginning-of-line) (point)))))
Jim Blandy's avatar
Jim Blandy committed
608

Roland McGrath's avatar
Roland McGrath committed
609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645
	  (if prefix (setq prefixlen (length prefix)
			   prefix (regexp-quote prefix)))
	  (if suffix (setq suffix (concat (regexp-quote suffix) "$")))
	  (while continue
	    ;; Look at next local variable spec.
	    (if selective-display (re-search-forward "[\n\C-m]")
	      (forward-line 1))
	    ;; Skip the prefix, if any.
	    (if prefix
		(if (looking-at prefix)
		    (forward-char prefixlen)
		  (error "Local variables entry is missing the prefix")))
	    ;; Find the variable name; strip whitespace.
	    (skip-chars-forward " \t")
	    (setq beg (point))
	    (skip-chars-forward "^:\n")
	    (if (eolp) (error "Missing colon in local variables entry"))
	    (skip-chars-backward " \t")
	    (let* ((str (buffer-substring beg (point)))
		   (var (read str))
		  val)
	      ;; Setting variable named "end" means end of list.
	      (if (string-equal (downcase str) "end")
		  (setq continue nil)
		;; Otherwise read the variable value.
		(skip-chars-forward "^:")
		(forward-char 1)
		(setq val (read (current-buffer)))
		(skip-chars-backward "\n")
		(skip-chars-forward " \t")
		(or (if suffix (looking-at suffix) (eolp))
		    (error "Local variables entry is terminated incorrectly"))
		;; Set the variable.  "Variables" mode and eval are funny.
		(cond ((eq var 'mode)
		       (funcall (intern (concat (downcase (symbol-name val))
						"-mode"))))
		      ((eq var 'eval)
Jim Blandy's avatar
Jim Blandy committed
646
		       (if (or ignore-local-eval
Roland McGrath's avatar
Roland McGrath committed
647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671
			       (string= (user-login-name) "root"))
			   (message "Ignoring `eval:' in file's local variables")
			 (save-excursion (eval val))))
		      (t (make-local-variable var)
			 (set var val))))))))))

(defun set-visited-file-name (filename)
  "Change name of file visited in current buffer to FILENAME.
The next time the buffer is saved it will go in the newly specified file.
nil or empty string as argument means make buffer not be visiting any file.
Remember to delete the initial contents of the minibuffer
if you wish to pass an empty string as the argument."
  (interactive "FSet visited file name: ")
  (if filename
      (setq filename
	    (if (string-equal filename "")
		nil
	      (expand-file-name filename))))
  (or (equal filename buffer-file-name)
      (null filename)
      (progn
	(lock-buffer filename)
	(unlock-buffer)))
  (setq buffer-file-name filename)
  (if filename				; make buffer name reflect filename.
Jim Blandy's avatar
Jim Blandy committed
672
      (let ((new-name (file-name-nondirectory buffer-file-name)))
Roland McGrath's avatar
Roland McGrath committed
673 674 675 676 677
	(if (string= new-name "")
	    (error "Empty file name"))
	(if (eq system-type 'vax-vms)
	    (setq new-name (downcase new-name)))
	(setq default-directory (file-name-directory buffer-file-name))
Jim Blandy's avatar
Jim Blandy committed
678
	(rename-buffer new-name t)))
Roland McGrath's avatar
Roland McGrath committed
679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831
  (setq buffer-backed-up nil)
  (clear-visited-file-modtime)
  ;; write-file-hooks is normally used for things like ftp-find-file
  ;; that visit things that are not local files as if they were files.
  ;; Changing to visit an ordinary local file instead should flush the hook.
  (kill-local-variable 'write-file-hooks)
  (kill-local-variable 'revert-buffer-function)
  (kill-local-variable 'backup-inhibited)
  ;; Turn off backup files for certain file names.
  ;; Since this is a permanent local, the major mode won't eliminate it.
  (and (not (funcall backup-enable-predicate buffer-file-name))
       (progn
	 (make-local-variable 'backup-inhibited)
	 (setq backup-inhibited t)))
  ;; If auto-save was not already on, turn it on if appropriate.
  (if (not buffer-auto-save-file-name)
      (auto-save-mode (and buffer-file-name auto-save-default)))
  (if buffer-file-name
      (set-buffer-modified-p t)))

(defun write-file (filename)
  "Write current buffer into file FILENAME.
Makes buffer visit that file, and marks it not modified."
;;  (interactive "FWrite file: ")
  (interactive
   (list (if buffer-file-name
	     (read-file-name "Write file: "
				 nil nil nil nil)
	   (read-file-name "Write file: "
			       (cdr (assq 'default-directory
					  (buffer-local-variables)))
			       nil nil (buffer-name)))))
  (or (null filename) (string-equal filename "")
      (set-visited-file-name filename))
  (set-buffer-modified-p t)
  (save-buffer))

(defun backup-buffer ()
  "Make a backup of the disk file visited by the current buffer, if appropriate.
This is normally done before saving the buffer the first time.
If the value is non-nil, it is the result of `file-modes' on the original
file; this means that the caller, after saving the buffer, should change
the modes of the new file to agree with the old modes."
  (if (and make-backup-files (not backup-inhibited)
	   (not buffer-backed-up)
	   (file-exists-p buffer-file-name)
	   (memq (aref (elt (file-attributes buffer-file-name) 8) 0)
		 '(?- ?l)))
      (let ((real-file-name buffer-file-name)
	    backup-info backupname targets setmodes)
	;; If specified name is a symbolic link, chase it to the target.
	;; Thus we make the backups in the directory where the real file is.
	(while (let ((tem (file-symlink-p real-file-name)))
		 (if tem
		     (setq real-file-name
			   (expand-file-name tem
					     (file-name-directory real-file-name))))
		 tem))
	(setq backup-info (find-backup-file-name real-file-name)
	      backupname (car backup-info)
	      targets (cdr backup-info))
;;;     (if (file-directory-p buffer-file-name)
;;;         (error "Cannot save buffer in directory %s" buffer-file-name))
        (condition-case ()
	    (let ((delete-old-versions
		   ;; If have old versions to maybe delete,
		   ;; ask the user to confirm now, before doing anything.
		   ;; But don't actually delete til later.
		   (and targets
			(or trim-versions-without-asking
			    (y-or-n-p (format "Delete excess backup versions of %s? "
					      real-file-name))))))
	      ;; Actually write the back up file.
	      (condition-case ()
		  (if (or file-precious-flag
;			  (file-symlink-p buffer-file-name)
			  backup-by-copying
			  (and backup-by-copying-when-linked
			       (> (file-nlinks real-file-name) 1))
			  (and backup-by-copying-when-mismatch
			       (let ((attr (file-attributes real-file-name)))
				 (or (nth 9 attr)
				     (/= (nth 2 attr) (user-uid))))))
		      (copy-file real-file-name backupname t t)
; rename-file should delete old backup.
;		    (condition-case ()
;			(delete-file backupname)
;		      (file-error nil))
		    (rename-file real-file-name backupname t)
		    (setq setmodes (file-modes backupname)))
		(file-error
		 ;; If trouble writing the backup, write it in ~.
		 (setq backupname (expand-file-name "~/%backup%~"))
		 (message "Cannot write backup file; backing up in ~/%%backup%%~")
		 (sleep-for 1)
		 (copy-file real-file-name backupname t t)))
	      (setq buffer-backed-up t)
	      ;; Now delete the old versions, if desired.
	      (if delete-old-versions
		  (while targets
		    (condition-case ()
			(delete-file (car targets))
		      (file-error nil))
		    (setq targets (cdr targets))))
	      setmodes)
	(file-error nil)))))

(defun file-name-sans-versions (name)
  "Return FILENAME sans backup versions or strings.
This is a separate procedure so your site-init or startup file can
redefine it."
  (substring name 0
             (if (eq system-type 'vax-vms)
		 ;; VMS version number is (a) semicolon, optional
		 ;; sign, zero or more digits or (b) period, option
		 ;; sign, zero or more digits, provided this is the
		 ;; second period encountered outside of the
		 ;; device/directory part of the file name.
                 (or (string-match ";[---+]?[0-9]*\\'" name)
                     (if (string-match "\\.[^]>:]*\\(\\.[---+]?[0-9]*\\)\\'"
                                       name)
                         (match-beginning 1))
                     (length name))
               (or (string-match "\\.~[0-9]+~\\'" name)
                   (string-match "~\\'" name)
                   (length name)))))

(defun make-backup-file-name (file)
  "Create the non-numeric backup file name for FILE.
This is a separate function so you can redefine it for customization."
  (concat file "~"))

(defun backup-file-name-p (file)
  "Return non-nil if FILE is a backup file name (numeric or not).
This is a separate function so you can redefine it for customization.
You may need to redefine `file-name-sans-versions' as well."
  (string-match "~$" file))

;; I believe there is no need to alter this behavior for VMS;
;; since backup files are not made on VMS, it should not get called.
(defun find-backup-file-name (fn)
  "Find a file name for a backup file, and suggestions for deletions.
Value is a list whose car is the name for the backup file
 and whose cdr is a list of old versions to consider deleting now."
  (if (eq version-control 'never)
      (list (make-backup-file-name fn))
    (let* ((base-versions (concat (file-name-nondirectory fn) ".~"))
	   (bv-length (length base-versions))
	   (possibilities (file-name-all-completions
			   base-versions
			   (file-name-directory fn)))
	   (versions (sort (mapcar 'backup-extract-version possibilities)
			   '<))
Jim Blandy's avatar
Jim Blandy committed
832
	   (high-water-mark (apply 'max 0 versions))
Roland McGrath's avatar
Roland McGrath committed
833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946
	   (deserve-versions-p
	    (or version-control
		(> high-water-mark 0)))
	   (number-to-delete (- (length versions)
				kept-old-versions kept-new-versions -1)))
      (if (not deserve-versions-p)
	  (list (make-backup-file-name fn))
	(cons (concat fn ".~" (int-to-string (1+ high-water-mark)) "~")
	      (if (> number-to-delete 0)
		  (mapcar (function (lambda (n)
				      (concat fn ".~" (int-to-string n) "~")))
			  (let ((v (nthcdr kept-old-versions versions)))
			    (rplacd (nthcdr (1- number-to-delete) v) ())
			    v))))))))

(defun backup-extract-version (fn)
  (if (and (string-match "[0-9]+~$" fn bv-length)
	   (= (match-beginning 0) bv-length))
      (string-to-int (substring fn bv-length -1))
      0))

(defun file-nlinks (filename)
  "Return number of names file FILENAME has."
  (car (cdr (file-attributes filename))))

(defun save-buffer (&optional args)
  "Save current buffer in visited file if modified.  Versions described below.
By default, makes the previous version into a backup file
 if previously requested or if this is the first save.
With 1 or 3 \\[universal-argument]'s, marks this version
 to become a backup when the next save is done.
With 2 or 3 \\[universal-argument]'s,
 unconditionally makes the previous version into a backup file.
With argument of 0, never makes the previous version into a backup file.

If a file's name is FOO, the names of its numbered backup versions are
 FOO.~i~ for various integers i.  A non-numbered backup file is called FOO~.
Numeric backups (rather than FOO~) will be made if value of
 `version-control' is not the atom `never' and either there are already
 numeric versions of the file being backed up, or `version-control' is
 non-nil.
We don't want excessive versions piling up, so there are variables
 `kept-old-versions', which tells Emacs how many oldest versions to keep,
 and `kept-new-versions', which tells how many newest versions to keep.
 Defaults are 2 old versions and 2 new.
`dired-kept-versions' controls dired's clean-directory (.) command.
If `trim-versions-without-asking' is nil, system will query user
 before trimming versions.  Otherwise it does it silently."
  (interactive "p")
  (let ((modp (buffer-modified-p))
	(large (> (buffer-size) 50000))
	(make-backup-files (and make-backup-files (not (eq args 0)))))
    (and modp (memq args '(16 64)) (setq buffer-backed-up nil))
    (if (and modp large) (message "Saving file %s..." (buffer-file-name)))
    (basic-save-buffer)
    (and modp (memq args '(4 64)) (setq buffer-backed-up nil))))

(defun delete-auto-save-file-if-necessary (&optional force)
  "Delete auto-save file for current buffer if `delete-auto-save-files' is t.
Normally delete only if the file was written by this Emacs since
the last real save, but optional arg FORCE non-nil means delete anyway."
  (and buffer-auto-save-file-name delete-auto-save-files
       (not (string= buffer-file-name buffer-auto-save-file-name))
       (or force (recent-auto-save-p))
       (progn
	 (condition-case ()
	     (delete-file buffer-auto-save-file-name)
	   (file-error nil))
	 (set-buffer-auto-saved))))

(defun basic-save-buffer ()
  "Save the current buffer in its visited file, if it has been modified."
  (interactive)
  (if (buffer-modified-p)
      (let ((recent-save (recent-auto-save-p))
	    setmodes tempsetmodes)
	;; On VMS, rename file and buffer to get rid of version number.
	(if (and (eq system-type 'vax-vms)
		 (not (string= buffer-file-name
			       (file-name-sans-versions buffer-file-name))))
	    (let (buffer-new-name)
	      ;; Strip VMS version number before save.
	      (setq buffer-file-name
		    (file-name-sans-versions buffer-file-name))
	      ;; Construct a (unique) buffer name to correspond.
	      (let ((buf (create-file-buffer (downcase buffer-file-name))))
		(setq buffer-new-name (buffer-name buf))
		(kill-buffer buf))
	      (rename-buffer buffer-new-name)))
	;; If buffer has no file name, ask user for one.
	(or buffer-file-name
	    (progn
	      (setq buffer-file-name
		    (expand-file-name (read-file-name "File to save in: ") nil)
		    default-directory (file-name-directory buffer-file-name))
	      (auto-save-mode auto-save-default)))
	(or (verify-visited-file-modtime (current-buffer))
	    (not (file-exists-p buffer-file-name))
	    (yes-or-no-p
	     (format "%s has changed since visited or saved.  Save anyway? "
		     (file-name-nondirectory buffer-file-name)))
	    (error "Save not confirmed"))
	(save-restriction
	  (widen)
	  (and (> (point-max) 1)
	       (/= (char-after (1- (point-max))) ?\n)
	       (or (eq require-final-newline t)
		   (and require-final-newline
			(y-or-n-p
			 (format "Buffer %s does not end in newline.  Add one? "
				 (buffer-name)))))
	       (save-excursion
		 (goto-char (point-max))
		 (insert ?\n)))
Jim Blandy's avatar
Jim Blandy committed
947
	  (let ((hooks (append write-contents-hooks write-file-hooks))
Roland McGrath's avatar
Roland McGrath committed
948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024
		(done nil))
	    (while (and hooks
			(not (setq done (funcall (car hooks)))))
	      (setq hooks (cdr hooks)))
	    ;; If a hook returned t, file is already "written".
	    (cond ((not done)
		   (if (not (file-writable-p buffer-file-name))
		       (let ((dir (file-name-directory buffer-file-name)))
			 (if (not (file-directory-p dir))
			     (error "%s is not a directory" dir)
			   (if (not (file-exists-p buffer-file-name))
			       (error "Directory %s write-protected" dir)
			     (if (yes-or-no-p
				  (format "File %s is write-protected; try to save anyway? "
					  (file-name-nondirectory
					   buffer-file-name)))
				 (setq tempsetmodes t)
			       (error "Attempt to save to a file which you aren't allowed to write"))))))
		   (or buffer-backed-up
		       (setq setmodes (backup-buffer)))
		   (if file-precious-flag
		       ;; If file is precious, rename it away before
		       ;; overwriting it.
		       (let ((rename t)
			     realname tempname temp)
			 ;; Chase symlinks; rename the ultimate actual file.
			 (setq realname buffer-file-name)
			 (while (setq temp (file-symlink-p realname))
			   (setq realname temp))
			 (setq tempname (concat realname "#"))
			 (condition-case ()
			     (progn (rename-file realname tempname t)
				    (setq setmodes (file-modes tempname)))
			   (file-error (setq rename nil tempname nil)))
			 (if (file-directory-p realname)
			     (error "%s is a directory" realname))
			 (unwind-protect
			     (progn (clear-visited-file-modtime)
				    (write-region (point-min) (point-max)
						  realname nil t)
				    (setq rename nil))
			   ;; If rename is still t, writing failed.
			   ;; So rename the old file back to original name,
			   (if rename
			       (progn
				 (rename-file tempname realname t)
				 (clear-visited-file-modtime))
			     ;; Otherwise we don't need the original file,
			     ;; so flush it, if we still have it.
			     ;; If rename failed due to name length restriction
			     ;; then TEMPNAME is now nil.
			     (if tempname
				 (condition-case ()
				     (delete-file tempname)
				   (error nil))))))
		     ;; If file not writable, see if we can make it writable
		     ;; temporarily while we write it.
		     ;; But no need to do so if we have just backed it up
		     ;; (setmodes is set) because that says we're superseding.
		     (cond ((and tempsetmodes (not setmodes))
			    ;; Change the mode back, after writing.
			    (setq setmodes (file-modes buffer-file-name))
			    (set-file-modes buffer-file-name 511)))
		     (write-region (point-min) (point-max)
				   buffer-file-name nil t)))))
	  (if setmodes
	      (condition-case ()
		   (set-file-modes buffer-file-name setmodes)
		(error nil))))
	;; If the auto-save file was recent before this command,
	;; delete it now.
	(delete-auto-save-file-if-necessary recent-save)
	(run-hooks 'after-save-hooks))
    (message "(No changes need to be saved)")))

(defun save-some-buffers (&optional arg exiting)
  "Save some modified file-visiting buffers.  Asks user about each one.
Jim Blandy's avatar
Jim Blandy committed
1025 1026 1027
Optional argument (the prefix) non-nil means save all with no questions.
Optional second argument EXITING means ask about certain non-file buffers
 as well as about file buffers."
Roland McGrath's avatar
Roland McGrath committed
1028
  (interactive "P")
Roland McGrath's avatar
Roland McGrath committed
1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048
  (save-excursion
    (if (zerop (map-y-or-n-p
		(function
		 (lambda (buffer)
		   (and (buffer-modified-p buffer)
			(or
			 (buffer-file-name buffer)
			 (and exiting
			      (progn
				(set-buffer buffer)
				(and buffer-offer-save (> (buffer-size) 0)))))
			(if arg
			    t
			  (if (buffer-file-name buffer)
			      (format "Save file %s? "
				      (buffer-file-name buffer))
			    (format "Save buffer %s? "
				    (buffer-name buffer)))))))
		(function
		 (lambda (buffer)
Jim Blandy's avatar
Jim Blandy committed
1049 1050
		   (set-buffer buffer)
		   (save-buffer)))
Roland McGrath's avatar
Roland McGrath committed
1051 1052 1053
		(buffer-list)
		'("buffer" "buffers" "save")))
	(message "(No files need saving)"))))
Roland McGrath's avatar
Roland McGrath committed
1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117

(defun not-modified (&optional arg)
  "Mark current buffer as unmodified, not needing to be saved.
With prefix arg, mark buffer as modified, so \\[save-buffer] will save."
  (interactive "P")
  (message (if arg "Modification-flag set"
	       "Modification-flag cleared"))
  (set-buffer-modified-p arg))

(defun toggle-read-only (&optional arg)
  "Change whether this buffer is visiting its file read-only.
With arg, set read-only iff arg is positive."
  (interactive "P")
  (setq buffer-read-only
	(if (null arg)
            (not buffer-read-only)
            (> (prefix-numeric-value arg) 0)))
  ;; Force mode-line redisplay
  (set-buffer-modified-p (buffer-modified-p)))

(defun insert-file (filename)
  "Insert contents of file FILENAME into buffer after point.
Set mark after the inserted text.

This function is meant for the user to run interactively.
Don't call it from programs!  Use `insert-file-contents' instead.
\(Its calling sequence is different; see its documentation)."
  (interactive "fInsert file: ")
  (let ((tem (insert-file-contents filename)))
    (push-mark (+ (point) (car (cdr tem))))))

(defun append-to-file (start end filename)
  "Append the contents of the region to the end of file FILENAME.
When called from a function, expects three arguments,
START, END and FILENAME.  START and END are buffer positions
saying what text to write."
  (interactive "r\nFAppend to file: ")
  (write-region start end filename t))

(defun file-newest-backup (filename)
  "Return most recent backup file for FILENAME or nil if no backups exist."
  (let* ((filename (expand-file-name filename))
	 (file (file-name-nondirectory filename))
	 (dir  (file-name-directory    filename))
	 (comp (file-name-all-completions file dir))
	 newest)
    (while comp
      (setq file (concat dir (car comp))
	    comp (cdr comp))
      (if (and (backup-file-name-p file)
	       (or (null newest) (file-newer-than-file-p file newest)))
	  (setq newest file)))
    newest))

(defun rename-uniquely ()
  "Rename current buffer to a similar name not already taken.
This function is useful for creating multiple shell process buffers
or multiple mail buffers, etc."
  (interactive)
  (let* ((new-buf (generate-new-buffer (buffer-name)))
	 (name (buffer-name new-buf)))
    (kill-buffer new-buf)
    (rename-buffer name)
    (set-buffer-modified-p (buffer-modified-p)))) ; force mode line update
Jim Blandy's avatar
Jim Blandy committed
1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130

(defun make-directory-path (path)
  "Create all the directories along path that don't exist yet."
  (interactive "Fdirectory path to create: ")
  (let ((path (directory-file-name (expand-file-name path)))
	create-list)
    (while (not (file-exists-p path))
      (setq create-list (cons path create-list)	    
	    path (directory-file-name (file-name-directory path))))
    (while create-list
      (make-directory (car create-list))
      (setq create-list (cdr create-list)))))

Roland McGrath's avatar
Roland McGrath committed
1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141

(put 'revert-buffer-function 'permanent-local t)
(defvar revert-buffer-function nil
  "Function to use to revert this buffer, or nil to do the default.")

(put 'revert-buffer-insert-file-contents-function 'permanent-local t)
(defvar revert-buffer-insert-file-contents-function nil
  "Function to use to insert contents when reverting this buffer.
Gets two args, first the nominal file name to use,
and second, t if reading the auto-save file.")

Jim Blandy's avatar
Jim Blandy committed
1142
(defun revert-buffer (&optional check-auto noconfirm)
Roland McGrath's avatar
Roland McGrath committed
1143 1144
  "Replace the buffer text with the text of the visited file on disk.
This undoes all changes since the file was visited or saved.
Jim Blandy's avatar
Jim Blandy committed
1145 1146 1147
With a prefix argument, offer to revert from latest auto-save file, if
that is more recent than the visited file.
When called from lisp, this is the first argument, CHECK-AUTO; it is optional.
Roland McGrath's avatar
Roland McGrath committed
1148 1149
Optional second argument NOCONFIRM means don't ask for confirmation at all.

Jim Blandy's avatar
Jim Blandy committed
1150 1151
If the value of `revert-buffer-function' is non-nil, it is called to
do the work."
Roland McGrath's avatar
Roland McGrath committed
1152 1153
  (interactive "P")
  (if revert-buffer-function
Jim Blandy's avatar
Jim Blandy committed
1154
      (funcall revert-buffer-function (not check-auto) noconfirm)
Roland McGrath's avatar
Roland McGrath committed
1155
    (let* ((opoint (point))
Jim Blandy's avatar
Jim Blandy committed
1156
	   (auto-save-p (and check-auto (recent-auto-save-p)
Roland McGrath's avatar
Roland McGrath committed
1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171
			     buffer-auto-save-file-name
			     (file-readable-p buffer-auto-save-file-name)
			     (y-or-n-p
   "Buffer has been auto-saved recently.  Revert from auto-save file? ")))
	   (file-name (if auto-save-p
			  buffer-auto-save-file-name
			buffer-file-name)))
      (cond ((null file-name)
	     (error "Buffer does not seem to be associated with any file"))
	    ((or noconfirm
		 (yes-or-no-p (format "Revert buffer from file %s? "
				      file-name)))
	     ;; If file was backed up but has changed since,
	     ;; we shd make another backup.
	     (and (not auto-save-p)
Jim Blandy's avatar
Jim Blandy committed
1172
		  (not (verify-visited-file-modtime (current-buffer)))
Roland McGrath's avatar
Roland McGrath committed
1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380
		  (setq buffer-backed-up nil))
	     ;; Get rid of all undo records for this buffer.
	     (or (eq buffer-undo-list t)
		 (setq buffer-undo-list nil))
	     (let ((buffer-read-only nil)
		   ;; Don't make undo records for the reversion.
		   (buffer-undo-list t))
	       (if revert-buffer-insert-file-contents-function
		   (funcall revert-buffer-insert-file-contents-function
			    file-name auto-save-p)
		 (if (not (file-exists-p file-name))
		     (error "File %s no longer exists!" file-name))
		 ;; Bind buffer-file-name to nil
		 ;; so that we don't try to lock the file.
		 (let ((buffer-file-name nil))
		   (or auto-save-p
		       (unlock-buffer))
		   (erase-buffer))
		 (insert-file-contents file-name (not auto-save-p))))
	     (goto-char (min opoint (point-max)))
	     (after-find-file nil)
	     t)))))

(defun recover-file (file)
  "Visit file FILE, but get contents from its last auto-save file."
  (interactive
   (let ((prompt-file buffer-file-name)
	 (file-name nil)
	 (file-dir nil))
     (and prompt-file
	  (setq file-name (file-name-nondirectory prompt-file)
		file-dir (file-name-directory prompt-file)))
     (list (read-file-name "Recover file: "
			       file-dir nil nil file-name))))
  (setq file (expand-file-name file))
  (if (auto-save-file-name-p file) (error "%s is an auto-save file" file))
  (let ((file-name (let ((buffer-file-name file))
		     (make-auto-save-file-name))))
    (cond ((not (file-newer-than-file-p file-name file))
	   (error "Auto-save file %s not current" file-name))
	  ((save-window-excursion
	     (if (not (eq system-type 'vax-vms))
		 (with-output-to-temp-buffer "*Directory*"
		   (buffer-disable-undo standard-output)
		   (call-process "ls" nil standard-output nil
				 "-l" file file-name)))
	     (yes-or-no-p (format "Recover auto save file %s? " file-name)))
	   (switch-to-buffer (find-file-noselect file t))
	   (let ((buffer-read-only nil))
	     (erase-buffer)
	     (insert-file-contents file-name nil))
	   (after-find-file nil))
	  (t (error "Recover-file cancelled.")))))

(defun kill-some-buffers ()
  "For each buffer, ask whether to kill it."
  (interactive)
  (let ((list (buffer-list)))
    (while list
      (let* ((buffer (car list))
	     (name (buffer-name buffer)))
	(and (not (string-equal name ""))
	     (/= (aref name 0) ? )
	     (yes-or-no-p
	      (format "Buffer %s %s.  Kill? "
		      name
		      (if (buffer-modified-p buffer)
			  "HAS BEEN EDITED" "is unmodified")))
	     (kill-buffer buffer)))
      (setq list (cdr list)))))

(defun auto-save-mode (arg)
  "Toggle auto-saving of contents of current buffer.
With ARG, turn auto-saving on if positive, else off."
  (interactive "P")
  (setq buffer-auto-save-file-name
        (and (if (null arg)
		 (not buffer-auto-save-file-name)
	       (or (eq arg t) (listp arg) (and (integerp arg) (> arg 0))))
	     (if (and buffer-file-name auto-save-visited-file-name
		      (not buffer-read-only))
		 buffer-file-name
	       (make-auto-save-file-name))))
  (if (interactive-p)
      (message "Auto-save %s (in this buffer)"
	       (if buffer-auto-save-file-name "on" "off")))
  buffer-auto-save-file-name)

(defun rename-auto-save-file ()
  "Adjust current buffer's auto save file name for current conditions.
Also rename any existing auto save file, if it was made in this session."
  (let ((osave buffer-auto-save-file-name))
    (setq buffer-auto-save-file-name
	  (make-auto-save-file-name))
    (if (and osave buffer-auto-save-file-name
	     (not (string= buffer-auto-save-file-name buffer-file-name))
	     (not (string= buffer-auto-save-file-name osave))
	     (file-exists-p osave)
	     (recent-auto-save-p))
	(rename-file osave buffer-auto-save-file-name t))))

(defun make-auto-save-file-name ()
  "Return file name to use for auto-saves of current buffer.
Does not consider `auto-save-visited-file-name' as that variable is checked
before calling this function.  You can redefine this for customization.
See also `auto-save-file-name-p'."
  (if buffer-file-name
      (concat (file-name-directory buffer-file-name)
	      "#"
	      (file-name-nondirectory buffer-file-name)
	      "#")
    ;; For non-file bfr, use bfr name and Emacs pid.
    (expand-file-name (format "#%s#%s#" (buffer-name) (make-temp-name "")))))

(defun auto-save-file-name-p (filename)
  "Return non-nil if FILENAME can be yielded by `make-auto-save-file-name'.
FILENAME should lack slashes.  You can redefine this for customization."
  (string-match "^#.*#$" filename))

(defconst list-directory-brief-switches
  (if (eq system-type 'vax-vms) "" "-CF")
  "*Switches for list-directory to pass to `ls' for brief listing,")

(defconst list-directory-verbose-switches
  (if (eq system-type 'vax-vms)
      "/PROTECTION/SIZE/DATE/OWNER/WIDTH=(OWNER:10)"
    "-l")
  "*Switches for list-directory to pass to `ls' for verbose listing,")

(defun list-directory (dirname &optional verbose)
  "Display a list of files in or matching DIRNAME, a la `ls'.
DIRNAME is globbed by the shell if necessary.
Prefix arg (second arg if noninteractive) means supply -l switch to `ls'.
Actions controlled by variables `list-directory-brief-switches'
and `list-directory-verbose-switches'."
  (interactive (let ((pfx current-prefix-arg))
		 (list (read-file-name (if pfx "List directory (verbose): "
					 "List directory (brief): ")
				       nil default-directory nil)
		       pfx)))
  (let ((switches (if verbose list-directory-verbose-switches
		    list-directory-brief-switches)))
    (or dirname (setq dirname default-directory))
    (setq dirname (expand-file-name dirname))
    (with-output-to-temp-buffer "*Directory*"
      (buffer-disable-undo standard-output)
      (princ "Directory ")
      (princ dirname)
      (terpri)
      (if (eq system-type 'vax-vms)
	  (vms-read-directory dirname switches standard-output)
	(if (file-directory-p dirname)
	    (save-excursion
	      (set-buffer "*Directory*")
	      (call-process "ls" nil standard-output nil switches
			    (setq default-directory
				  (file-name-as-directory dirname))))
	  (let ((default-directory (file-name-directory dirname)))
	    (if (file-exists-p default-directory)
		(call-process shell-file-name nil standard-output nil
			      "-c" (concat "exec ls "
					   switches " "
					   (file-name-nondirectory dirname)))
	      (princ "No such directory: ")
	      (princ dirname)
	      (terpri))))))))

(defun save-buffers-kill-emacs (&optional arg)
  "Offer to save each buffer, then kill this Emacs process.
With prefix arg, silently save all file-visiting buffers, then kill."
  (interactive "P")
  (save-some-buffers arg t)
  (and (or (not (memq t (mapcar (function
				  (lambda (buf) (and (buffer-file-name buf)
						     (buffer-modified-p buf))))
				(buffer-list))))
	   (yes-or-no-p "Modified buffers exist; exit anyway? "))
       (or (not (fboundp 'process-list))
	   ;; process-list is not defined on VMS.
	   (let ((processes (process-list))
		 active)
	     (while processes
	       (and (memq (process-status (car processes)) '(run stop))
		    (let ((val (process-kill-without-query (car processes))))
		      (process-kill-without-query (car processes) val)
		      val)
		    (setq active t))
	       (setq processes (cdr processes)))
	     (or (not active)
		 (yes-or-no-p "Active processes exist; kill them and exit anyway? "))))
       (kill-emacs)))

(define-key ctl-x-map "\C-f" 'find-file)
(define-key ctl-x-map "\C-q" 'toggle-read-only)
(define-key ctl-x-map "\C-r" 'find-file-read-only)
(define-key ctl-x-map "\C-v" 'find-alternate-file)
(define-key ctl-x-map "\C-s" 'save-buffer)
(define-key ctl-x-map "s" 'save-some-buffers)
(define-key ctl-x-map "\C-w" 'write-file)
(define-key ctl-x-map "i" 'insert-file)
(define-key esc-map "~" 'not-modified)
(define-key ctl-x-map "\C-d" 'list-directory)
(define-key ctl-x-map "\C-c" 'save-buffers-kill-emacs)

(define-key ctl-x-4-map "f" 'find-file-other-window)
(define-key ctl-x-4-map "r" 'find-file-read-only-other-window)
(define-key ctl-x-4-map "\C-f" 'find-file-other-window)
(define-key ctl-x-4-map "b" 'switch-to-buffer-other-window)
Jim Blandy's avatar
Jim Blandy committed
1381 1382 1383 1384

(define-key ctl-x-3-map "b" 'switch-to-buffer-other-screen)
(define-key ctl-x-3-map "f" 'find-file-other-screen)
(define-key ctl-x-3-map "r" 'find-file-read-only-other-screen)