1 ;;; tar-mode.el --- simple editing of tar files from GNU emacs
3 ;; Copyright (C) 1990, 1991, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
4 ;; 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008 Free Software Foundation, Inc.
6 ;; Author: Jamie Zawinski <jwz@lucid.com>
8 ;; Created: 04 Apr 1990
11 ;; This file is part of GNU Emacs.
13 ;; GNU Emacs is free software: you can redistribute it and/or modify
14 ;; it under the terms of the GNU General Public License as published by
15 ;; the Free Software Foundation, either version 3 of the License, or
16 ;; (at your option) any later version.
18 ;; GNU Emacs is distributed in the hope that it will be useful,
19 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
20 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
21 ;; GNU General Public License for more details.
23 ;; You should have received a copy of the GNU General Public License
24 ;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>.
28 ;; This package attempts to make dealing with Unix 'tar' archives easier.
29 ;; When this code is loaded, visiting a file whose name ends in '.tar' will
30 ;; cause the contents of that archive file to be displayed in a Dired-like
31 ;; listing. It is then possible to use the customary Dired keybindings to
32 ;; extract sub-files from that archive, either by reading them into their own
33 ;; editor buffers, or by copying them directly to arbitrary files on disk.
34 ;; It is also possible to delete sub-files from within the tar file and write
35 ;; the modified archive back to disk, or to edit sub-files within the archive
36 ;; and re-insert the modified files into the archive. See the documentation
37 ;; string of tar-mode for more info.
39 ;; This code now understands the extra fields that GNU tar adds to tar files.
41 ;; This interacts correctly with "uncompress.el" in the Emacs library,
44 ;; (autoload 'uncompress-while-visiting "uncompress")
45 ;; (setq auto-mode-alist (cons '("\\.Z$" . uncompress-while-visiting)
48 ;; Do not attempt to use tar-mode.el with crypt.el, you will lose.
50 ;; *************** TO DO ***************
52 ;; o chmod should understand "a+x,og-w".
54 ;; o It's not possible to add a NEW file to a tar archive; not that
55 ;; important, but still...
57 ;; o The code is less efficient that it could be - in a lot of places, I
58 ;; pull a 512-character string out of the buffer and parse it, when I could
59 ;; be parsing it in place, not garbaging a string. Should redo that.
61 ;; o I'd like a command that searches for a string/regexp in every subfile
62 ;; of an archive, where <esc> would leave you in a subfile-edit buffer.
63 ;; (Like the Meta-R command of the Zmacs mail reader.)
65 ;; o Sometimes (but not always) reverting the tar-file buffer does not
66 ;; re-grind the listing, and you are staring at the binary tar data.
67 ;; Typing 'g' again immediately after that will always revert and re-grind
68 ;; it, though. I have no idea why this happens.
70 ;; o Tar-mode interacts poorly with crypt.el and zcat.el because the tar
71 ;; write-file-hook actually writes the file. Instead it should remove the
72 ;; header (and conspire to put it back afterwards) so that other write-file
73 ;; hooks which frob the buffer have a chance to do their dirty work. There
74 ;; might be a problem if the tar write-file-hook does not come *first* on
77 ;; o Block files, sparse files, continuation files, and the various header
78 ;; types aren't editable. Actually I don't know that they work at all.
82 ;; Why does tar-mode edit the file itself instead of using tar?
84 ;; That means that you can edit tar files which you don't have room for
85 ;; on your local disk.
87 ;; I don't know about recent features in gnu tar, but old versions of tar
88 ;; can't replace a file in the middle of a tar file with a new version.
89 ;; Tar-mode can. I don't think tar can do things like chmod the subfiles.
90 ;; An implementation which involved unpacking and repacking the file into
91 ;; some scratch directory would be very wasteful, and wouldn't be able to
92 ;; preserve the file owners.
97 "Simple editing of tar files."
101 (defcustom tar-anal-blocksize 20
102 "The blocksize of tar files written by Emacs, or nil, meaning don't care.
103 The blocksize of a tar file is not really the size of the blocks; rather, it is
104 the number of blocks written with one system call. When tarring to a tape,
105 this is the size of the *tape* blocks, but when writing to a file, it doesn't
106 matter much. The only noticeable difference is that if a tar file does not
107 have a blocksize of 20, tar will tell you that; all this really controls is
108 how many null padding bytes go on the end of the tar file."
109 :type '(choice integer (const nil))
112 (defcustom tar-update-datestamp nil
113 "Non-nil means Tar mode should play fast and loose with sub-file datestamps.
114 If this is true, then editing and saving a tar file entry back into its
115 tar file will update its datestamp. If false, the datestamp is unchanged.
116 You may or may not want this - it is good in that you can tell when a file
117 in a tar archive has been changed, but it is bad for the same reason that
118 editing a file in the tar archive at all is bad - the changed version of
119 the file never exists on disk."
123 (defcustom tar-mode-show-date nil
124 "Non-nil means Tar mode should show the date/time of each subfile.
125 This information is useful, but it takes screen space away from file names."
129 (defvar tar-parse-info nil)
130 (defvar tar-header-offset nil)
131 (defvar tar-superior-buffer nil)
132 (defvar tar-superior-descriptor nil)
133 (defvar tar-subfile-mode nil)
134 (defvar tar-file-name-coding-system nil)
136 (put 'tar-parse-info 'permanent-local t)
137 (put 'tar-header-offset 'permanent-local t)
138 (put 'tar-superior-buffer 'permanent-local t)
139 (put 'tar-superior-descriptor 'permanent-local t)
140 (put 'tar-file-name-coding-system 'permanent-local t)
142 (defmacro tar-setf (form val)
143 "A mind-numbingly simple implementation of setf."
144 (let ((mform (macroexpand form (and (boundp 'byte-compile-macro-environment)
145 byte-compile-macro-environment))))
146 (cond ((symbolp mform) (list 'setq mform val))
147 ((not (consp mform)) (error "can't setf %s" form))
148 ((eq (car mform) 'aref)
149 (list 'aset (nth 1 mform) (nth 2 mform) val))
150 ((eq (car mform) 'car)
151 (list 'setcar (nth 1 mform) val))
152 ((eq (car mform) 'cdr)
153 (list 'setcdr (nth 1 mform) val))
154 (t (error "don't know how to setf %s" form)))))
156 ;;; down to business.
158 (defmacro make-tar-header (name mode uid git size date ck lt ln
159 magic uname gname devmaj devmin)
160 (list 'vector name mode uid git size date ck lt ln
161 magic uname gname devmaj devmin))
163 (defmacro tar-header-name (x) (list 'aref x 0))
164 (defmacro tar-header-mode (x) (list 'aref x 1))
165 (defmacro tar-header-uid (x) (list 'aref x 2))
166 (defmacro tar-header-gid (x) (list 'aref x 3))
167 (defmacro tar-header-size (x) (list 'aref x 4))
168 (defmacro tar-header-date (x) (list 'aref x 5))
169 (defmacro tar-header-checksum (x) (list 'aref x 6))
170 (defmacro tar-header-link-type (x) (list 'aref x 7))
171 (defmacro tar-header-link-name (x) (list 'aref x 8))
172 (defmacro tar-header-magic (x) (list 'aref x 9))
173 (defmacro tar-header-uname (x) (list 'aref x 10))
174 (defmacro tar-header-gname (x) (list 'aref x 11))
175 (defmacro tar-header-dmaj (x) (list 'aref x 12))
176 (defmacro tar-header-dmin (x) (list 'aref x 13))
178 (defmacro make-tar-desc (data-start tokens)
179 (list 'cons data-start tokens))
181 (defmacro tar-desc-data-start (x) (list 'car x))
182 (defmacro tar-desc-tokens (x) (list 'cdr x))
184 (defconst tar-name-offset 0)
185 (defconst tar-mode-offset (+ tar-name-offset 100))
186 (defconst tar-uid-offset (+ tar-mode-offset 8))
187 (defconst tar-gid-offset (+ tar-uid-offset 8))
188 (defconst tar-size-offset (+ tar-gid-offset 8))
189 (defconst tar-time-offset (+ tar-size-offset 12))
190 (defconst tar-chk-offset (+ tar-time-offset 12))
191 (defconst tar-linkp-offset (+ tar-chk-offset 8))
192 (defconst tar-link-offset (+ tar-linkp-offset 1))
193 ;;; GNU-tar specific slots.
194 (defconst tar-magic-offset (+ tar-link-offset 100))
195 (defconst tar-uname-offset (+ tar-magic-offset 8))
196 (defconst tar-gname-offset (+ tar-uname-offset 32))
197 (defconst tar-dmaj-offset (+ tar-gname-offset 32))
198 (defconst tar-dmin-offset (+ tar-dmaj-offset 8))
199 (defconst tar-prefix-offset (+ tar-dmin-offset 8))
200 (defconst tar-end-offset (+ tar-prefix-offset 155))
202 (defun tar-header-block-tokenize (string)
203 "Return a `tar-header' structure.
204 This is a list of name, mode, uid, gid, size,
205 write-date, checksum, link-type, and link-name."
206 (setq string (string-as-unibyte string))
207 (cond ((< (length string) 512) nil)
208 (;(some 'plusp string) ; <-- oops, massive cycle hog!
209 (or (not (= 0 (aref string 0))) ; This will do.
210 (not (= 0 (aref string 101))))
211 (let* ((name-end tar-mode-offset)
212 (link-end (1- tar-magic-offset))
213 (uname-end (1- tar-gname-offset))
214 (gname-end (1- tar-dmaj-offset))
215 (link-p (aref string tar-linkp-offset))
216 (magic-str (substring string tar-magic-offset (1- tar-uname-offset)))
217 (uname-valid-p (or (string= "ustar " magic-str) (string= "GNUtar " magic-str)
218 (string= "ustar\0000" magic-str)))
220 (nulsexp "[^\000]*\000"))
221 (when (string-match nulsexp string tar-name-offset)
222 (setq name-end (min name-end (1- (match-end 0)))))
223 (when (string-match nulsexp string tar-link-offset)
224 (setq link-end (min link-end (1- (match-end 0)))))
225 (when (string-match nulsexp string tar-uname-offset)
226 (setq uname-end (min uname-end (1- (match-end 0)))))
227 (when (string-match nulsexp string tar-gname-offset)
228 (setq gname-end (min gname-end (1- (match-end 0)))))
229 (setq name (substring string tar-name-offset name-end)
230 link-p (if (or (= link-p 0) (= link-p ?0))
233 (setq linkname (substring string tar-link-offset link-end))
234 (when (and uname-valid-p
235 (string-match nulsexp string tar-prefix-offset)
236 (> (match-end 0) (1+ tar-prefix-offset)))
237 (setq name (concat (substring string tar-prefix-offset
240 (if default-enable-multibyte-characters
242 (decode-coding-string name tar-file-name-coding-system)
244 (decode-coding-string linkname
245 tar-file-name-coding-system)))
246 (if (and (null link-p) (string-match "/\\'" name)) (setq link-p 5)) ; directory
249 (tar-parse-octal-integer string tar-mode-offset tar-uid-offset)
250 (tar-parse-octal-integer string tar-uid-offset tar-gid-offset)
251 (tar-parse-octal-integer string tar-gid-offset tar-size-offset)
252 (tar-parse-octal-integer string tar-size-offset tar-time-offset)
253 (tar-parse-octal-long-integer string tar-time-offset tar-chk-offset)
254 (tar-parse-octal-integer string tar-chk-offset tar-linkp-offset)
258 (and uname-valid-p (substring string tar-uname-offset uname-end))
259 (and uname-valid-p (substring string tar-gname-offset gname-end))
260 (tar-parse-octal-integer string tar-dmaj-offset tar-dmin-offset)
261 (tar-parse-octal-integer string tar-dmin-offset tar-prefix-offset)
263 (t 'empty-tar-block)))
266 (defun tar-parse-octal-integer (string &optional start end)
267 (if (null start) (setq start 0))
268 (if (null end) (setq end (length string)))
269 (if (= (aref string start) 0)
273 (setq n (if (< (aref string start) ?0) n
274 (+ (* n 8) (- (aref string start) ?0)))
278 (defun tar-parse-octal-long-integer (string &optional start end)
279 (if (null start) (setq start 0))
280 (if (null end) (setq end (length string)))
281 (if (= (aref string start) 0)
286 (if (>= (aref string start) ?0)
287 (setq lo (+ (* lo 8) (- (aref string start) ?0))
288 hi (+ (* hi 8) (ash lo -16))
289 lo (logand lo 65535)))
290 (setq start (1+ start)))
293 (defun tar-parse-octal-integer-safe (string)
294 (if (zerop (length string)) (error "empty string"))
296 (if (or (< c ?0) (> c ?7))
297 (error "`%c' is not an octal digit" c)))
299 (tar-parse-octal-integer string))
302 (defun tar-header-block-checksum (string)
303 "Compute and return a tar-acceptable checksum for this block."
304 (setq string (string-as-unibyte string))
305 (let* ((chk-field-start tar-chk-offset)
306 (chk-field-end (+ chk-field-start 8))
309 ;; Add up all of the characters except the ones in the checksum field.
310 ;; Add that field as if it were filled with spaces.
311 (while (< i chk-field-start)
312 (setq sum (+ sum (aref string i))
314 (setq i chk-field-end)
316 (setq sum (+ sum (aref string i))
320 (defun tar-header-block-check-checksum (hblock desired-checksum file-name)
321 "Beep and print a warning if the checksum doesn't match."
322 (if (not (= desired-checksum (tar-header-block-checksum hblock)))
323 (progn (beep) (message "Invalid checksum for file %s!" file-name))))
325 (defun tar-clip-time-string (time)
326 (let ((str (current-time-string time)))
327 (concat " " (substring str 4 16) (substring str 19 24))))
329 (defun tar-grind-file-mode (mode)
330 "Construct a `-rw--r--r--' string indicating MODE.
331 MODE should be an integer which is a file mode value."
333 (if (zerop (logand 256 mode)) ?- ?r)
334 (if (zerop (logand 128 mode)) ?- ?w)
335 (if (zerop (logand 1024 mode)) (if (zerop (logand 64 mode)) ?- ?x) ?s)
336 (if (zerop (logand 32 mode)) ?- ?r)
337 (if (zerop (logand 16 mode)) ?- ?w)
338 (if (zerop (logand 2048 mode)) (if (zerop (logand 8 mode)) ?- ?x) ?s)
339 (if (zerop (logand 4 mode)) ?- ?r)
340 (if (zerop (logand 2 mode)) ?- ?w)
341 (if (zerop (logand 1 mode)) ?- ?x)))
343 (defun tar-header-block-summarize (tar-hblock &optional mod-p)
344 "Return a line similar to the output of `tar -vtf'."
345 (let ((name (tar-header-name tar-hblock))
346 (mode (tar-header-mode tar-hblock))
347 (uid (tar-header-uid tar-hblock))
348 (gid (tar-header-gid tar-hblock))
349 (uname (tar-header-uname tar-hblock))
350 (gname (tar-header-gname tar-hblock))
351 (size (tar-header-size tar-hblock))
352 (time (tar-header-date tar-hblock))
353 ;; (ck (tar-header-checksum tar-hblock))
354 (type (tar-header-link-type tar-hblock))
355 (link-name (tar-header-link-name tar-hblock)))
356 (format "%c%c%s%8s/%-8s%7s%s %s%s"
358 (cond ((or (eq type nil) (eq type 0)) ?-)
359 ((eq type 1) ?h) ; link
360 ((eq type 2) ?l) ; symlink
361 ((eq type 3) ?c) ; char special
362 ((eq type 4) ?b) ; block special
363 ((eq type 5) ?d) ; directory
364 ((eq type 6) ?p) ; FIFO/pipe
365 ((eq type 20) ?*) ; directory listing
366 ((eq type 28) ?L) ; next has longname
367 ((eq type 29) ?M) ; multivolume continuation
368 ((eq type 35) ?S) ; sparse
369 ((eq type 38) ?V) ; volume header
370 ((eq type 55) ?H) ; extended pax header
373 (tar-grind-file-mode mode)
374 (if (= 0 (length uname)) uid uname)
375 (if (= 0 (length gname)) gid gname)
377 (if tar-mode-show-date (tar-clip-time-string time) "")
379 'mouse-face 'highlight
380 'help-echo "mouse-2: extract this file into a buffer")
381 (if (or (eq type 1) (eq type 2))
382 (concat (if (= type 1) " ==> " " --> ") link-name)
385 (defun tar-untar-buffer ()
386 "Extract all archive members in the tar-file into the current directory."
388 (let ((multibyte enable-multibyte-characters))
392 (set-buffer-multibyte nil)
393 (dolist (descriptor tar-parse-info)
394 (let* ((tokens (tar-desc-tokens descriptor))
395 (name (tar-header-name tokens))
396 (dir (if (eq (tar-header-link-type tokens) 5)
398 (file-name-directory name)))
399 (start (+ (tar-desc-data-start descriptor)
400 (- tar-header-offset (point-min))))
401 (end (+ start (tar-header-size tokens))))
402 (unless (file-directory-p name)
403 (message "Extracting %s" name)
404 (if (and dir (not (file-exists-p dir)))
405 (make-directory dir t))
406 (unless (file-directory-p name)
407 (write-region start end name))
408 (set-file-modes name (tar-header-mode tokens))))))
410 (set-buffer-multibyte 'to)))))
412 (defun tar-summarize-buffer ()
413 "Parse the contents of the tar file in the current buffer.
414 Place a dired-like listing on the front;
415 then narrow to it, so that only that listing
416 is visible (and the real data of the buffer is hidden)."
417 (let ((modified (buffer-modified-p)))
418 (set-buffer-multibyte nil)
422 (make-progress-reporter "Parsing tar file..."
423 (point-min) (max 1 (- (buffer-size) 1024))))
425 (while (and (<= (+ pos 512) (point-max))
426 (not (eq 'empty-tar-block
428 (tar-header-block-tokenize
429 (buffer-substring pos (+ pos 512)))))))
430 (setq pos (+ pos 512))
431 (when (equal (tar-header-name tokens) "././@LongLink")
432 ;; This is a GNU Tar long-file-name header.
433 (let* ((size (tar-header-size tokens))
434 ;; -1 so as to strip the terminating 0 byte.
435 (name (buffer-substring pos (+ pos size -1))))
436 (setq pos (+ pos (ash (ash (+ 511 size) -9) 9)))
437 (setq tokens (tar-header-block-tokenize
438 (buffer-substring pos (+ pos 512))))
439 (tar-setf (tar-header-name tokens) name)
440 (setq pos (+ pos 512))))
441 (progress-reporter-update progress-reporter pos)
442 (if (memq (tar-header-link-type tokens) '(20 55))
443 ;; Foo. There's an extra empty block after these.
444 (setq pos (+ pos 512)))
445 (let ((size (tar-header-size tokens)))
447 (error "%s has size %s - corrupted"
448 (tar-header-name tokens) size))
450 ;; This is just too slow. Don't really ened it anyway....
451 ;;(tar-header-block-check-checksum
452 ;; hblock (tar-header-block-checksum hblock)
453 ;; (tar-header-name tokens))
455 (push (make-tar-desc pos tokens) result)
457 (and (null (tar-header-link-type tokens))
459 ;; Round up to a multiple of 512.
460 (setq pos (+ pos (ash (ash (+ 511 size) -9) 9))))))
461 (make-local-variable 'tar-parse-info)
462 (setq tar-parse-info (nreverse result))
463 ;; A tar file should end with a block or two of nulls,
464 ;; but let's not get a fatal error if it doesn't.
465 (if (eq tokens 'empty-tar-block)
466 (progress-reporter-done progress-reporter)
467 (message "Warning: premature EOF parsing tar file")))
468 ;; Obey the user's preference for the use of uni/multibytes.
469 (if default-enable-multibyte-characters
470 (set-buffer-multibyte 'to))
471 (goto-char (point-min))
472 (let ((inhibit-read-only t)
473 ;; Collect summary lines and insert them all at once since tar files
474 ;; can be pretty big.
478 (tar-header-block-summarize (tar-desc-tokens tar-desc)))
481 (insert total-summaries "\n"))
482 (narrow-to-region (point-min) (point))
483 (set (make-local-variable 'tar-header-offset) (position-bytes (point)))
484 (goto-char (point-min))
485 (restore-buffer-modified-p modified)))
488 (let ((map (make-keymap)))
489 (suppress-keymap map)
490 (define-key map " " 'tar-next-line)
491 (define-key map "C" 'tar-copy)
492 (define-key map "d" 'tar-flag-deleted)
493 (define-key map "\^D" 'tar-flag-deleted)
494 (define-key map "e" 'tar-extract)
495 (define-key map "f" 'tar-extract)
496 (define-key map "\C-m" 'tar-extract)
497 (define-key map [mouse-2] 'tar-mouse-extract)
498 (define-key map "g" 'revert-buffer)
499 (define-key map "h" 'describe-mode)
500 (define-key map "n" 'tar-next-line)
501 (define-key map "\^N" 'tar-next-line)
502 (define-key map [down] 'tar-next-line)
503 (define-key map "o" 'tar-extract-other-window)
504 (define-key map "p" 'tar-previous-line)
505 (define-key map "q" 'quit-window)
506 (define-key map "\^P" 'tar-previous-line)
507 (define-key map [up] 'tar-previous-line)
508 (define-key map "R" 'tar-rename-entry)
509 (define-key map "u" 'tar-unflag)
510 (define-key map "v" 'tar-view)
511 (define-key map "x" 'tar-expunge)
512 (define-key map "\177" 'tar-unflag-backwards)
513 (define-key map "E" 'tar-extract-other-window)
514 (define-key map "M" 'tar-chmod-entry)
515 (define-key map "G" 'tar-chgrp-entry)
516 (define-key map "O" 'tar-chown-entry)
517 ;; Let mouse-1 follow the link.
518 (define-key map [follow-link] 'mouse-face)
520 ;; Make menu bar items.
522 ;; Get rid of the Edit menu bar item to save space.
523 (define-key map [menu-bar edit] 'undefined)
525 (define-key map [menu-bar immediate]
526 (cons "Immediate" (make-sparse-keymap "Immediate")))
528 (define-key map [menu-bar immediate view]
529 '("View This File" . tar-view))
530 (define-key map [menu-bar immediate display]
531 '("Display in Other Window" . tar-display-other-window))
532 (define-key map [menu-bar immediate find-file-other-window]
533 '("Find in Other Window" . tar-extract-other-window))
534 (define-key map [menu-bar immediate find-file]
535 '("Find This File" . tar-extract))
537 (define-key map [menu-bar mark]
538 (cons "Mark" (make-sparse-keymap "Mark")))
540 (define-key map [menu-bar mark unmark-all]
541 '("Unmark All" . tar-clear-modification-flags))
542 (define-key map [menu-bar mark deletion]
543 '("Flag" . tar-flag-deleted))
544 (define-key map [menu-bar mark unmark]
545 '("Unflag" . tar-unflag))
547 (define-key map [menu-bar operate]
548 (cons "Operate" (make-sparse-keymap "Operate")))
550 (define-key map [menu-bar operate chown]
551 '("Change Owner..." . tar-chown-entry))
552 (define-key map [menu-bar operate chgrp]
553 '("Change Group..." . tar-chgrp-entry))
554 (define-key map [menu-bar operate chmod]
555 '("Change Mode..." . tar-chmod-entry))
556 (define-key map [menu-bar operate rename]
557 '("Rename to..." . tar-rename-entry))
558 (define-key map [menu-bar operate copy]
559 '("Copy to..." . tar-copy))
560 (define-key map [menu-bar operate expunge]
561 '("Expunge Marked Files" . tar-expunge))
564 "Local keymap for Tar mode listings.")
567 ;; tar mode is suitable only for specially formatted data.
568 (put 'tar-mode 'mode-class 'special)
569 (put 'tar-subfile-mode 'mode-class 'special)
572 (define-derived-mode tar-mode nil "Tar"
573 "Major mode for viewing a tar file as a dired-like listing of its contents.
574 You can move around using the usual cursor motion commands.
575 Letters no longer insert themselves.
576 Type `e' to pull a file out of the tar file and into its own buffer;
577 or click mouse-2 on the file's line in the Tar mode buffer.
578 Type `c' to copy an entry from the tar file into another file on disk.
580 If you edit a sub-file of this archive (as with the `e' command) and
581 save it with \\[save-buffer], the contents of that buffer will be
582 saved back into the tar-file buffer; in this way you can edit a file
583 inside of a tar archive without extracting it and re-archiving it.
585 See also: variables `tar-update-datestamp' and `tar-anal-blocksize'.
587 ;; this is not interactive because you shouldn't be turning this
588 ;; mode on and off. You can corrupt things that way.
589 ;; rms: with permanent locals, it should now be possible to make this work
590 ;; interactively in some reasonable fashion.
591 (make-local-variable 'tar-header-offset)
592 (make-local-variable 'tar-parse-info)
593 (set (make-local-variable 'require-final-newline) nil) ; binary data, dude...
594 (set (make-local-variable 'revert-buffer-function) 'tar-mode-revert)
595 (set (make-local-variable 'local-enable-local-variables) nil)
596 (set (make-local-variable 'next-line-add-newlines) nil)
597 (set (make-local-variable 'tar-file-name-coding-system)
598 (or file-name-coding-system
599 default-file-name-coding-system
600 locale-coding-system))
601 ;; Prevent loss of data when saving the file.
602 (set (make-local-variable 'file-precious-flag) t)
604 (set (make-local-variable 'write-contents-functions) '(tar-mode-write-file))
605 (buffer-disable-undo)
607 (if (and (boundp 'tar-header-offset) tar-header-offset)
608 (narrow-to-region (point-min) tar-header-offset)
609 (tar-summarize-buffer)
613 (defun tar-subfile-mode (p)
614 "Minor mode for editing an element of a tar-file.
615 This mode arranges for \"saving\" this buffer to write the data
616 into the tar-file buffer that it came from. The changes will actually
617 appear on disk when you save the tar-file's buffer."
619 (or (and (boundp 'tar-superior-buffer) tar-superior-buffer)
620 (error "This buffer is not an element of a tar file"))
621 ;; Don't do this, because it is redundant and wastes mode line space.
622 ;; (or (assq 'tar-subfile-mode minor-mode-alist)
623 ;; (setq minor-mode-alist (append minor-mode-alist
624 ;; (list '(tar-subfile-mode " TarFile")))))
625 (make-local-variable 'tar-subfile-mode)
626 (setq tar-subfile-mode
628 (not tar-subfile-mode)
629 (> (prefix-numeric-value p) 0)))
630 (cond (tar-subfile-mode
631 (add-hook 'write-file-functions 'tar-subfile-save-buffer nil t)
632 ;; turn off auto-save.
634 (setq buffer-auto-save-file-name nil)
635 (run-hooks 'tar-subfile-mode-hook))
637 (remove-hook 'write-file-functions 'tar-subfile-save-buffer t))))
640 ;; Revert the buffer and recompute the dired-like listing.
641 (defun tar-mode-revert (&optional no-auto-save no-confirm)
642 (let ((revert-buffer-function nil)
643 (old-offset tar-header-offset)
645 (setq tar-header-offset nil)
647 (and (revert-buffer t no-confirm)
651 ;; If the revert was canceled,
652 ;; put back the old value of tar-header-offset.
654 (setq tar-header-offset old-offset)))))
657 (defun tar-next-line (arg)
658 "Move cursor vertically down ARG lines and to the start of the filename."
661 (if (eobp) nil (forward-char (if tar-mode-show-date 54 36))))
663 (defun tar-previous-line (arg)
664 "Move cursor vertically up ARG lines and to the start of the filename."
666 (tar-next-line (- arg)))
668 (defun tar-current-descriptor (&optional noerror)
669 "Return the tar-descriptor of the current line, or signals an error."
670 ;; I wish lines had plists, like in ZMACS...
671 (or (nth (count-lines (point-min)
672 (save-excursion (beginning-of-line) (point)))
676 (error "This line does not describe a tar-file entry"))))
678 (defun tar-get-descriptor ()
679 (let* ((descriptor (tar-current-descriptor))
680 (tokens (tar-desc-tokens descriptor))
681 (size (tar-header-size tokens))
682 (link-p (tar-header-link-type tokens)))
684 (error "This is %s, not a real file"
685 (cond ((eq link-p 5) "a directory")
686 ((eq link-p 20) "a tar directory header")
687 ((eq link-p 28) "a next has longname")
688 ((eq link-p 29) "a multivolume-continuation")
689 ((eq link-p 35) "a sparse entry")
690 ((eq link-p 38) "a volume header")
691 ((eq link-p 55) "an extended pax header")
693 (if (zerop size) (message "This is a zero-length file"))
696 (defun tar-mouse-extract (event)
697 "Extract a file whose tar directory line you click on."
699 (with-current-buffer (window-buffer (posn-window (event-end event)))
701 (goto-char (posn-point (event-end event)))
702 ;; Just make sure this doesn't get an error.
703 (tar-get-descriptor)))
704 (select-window (posn-window (event-end event)))
705 (goto-char (posn-point (event-end event)))
708 (defun tar-file-name-handler (op &rest args)
709 "Helper function for `tar-extract'."
710 (or (eq op 'file-exists-p)
711 (let ((file-name-handler-alist nil))
714 (defun tar-extract (&optional other-window-p)
715 "In Tar mode, extract this entry of the tar file into its own buffer."
717 (let* ((view-p (eq other-window-p 'view))
718 (descriptor (tar-get-descriptor))
719 (tokens (tar-desc-tokens descriptor))
720 (name (tar-header-name tokens))
721 (size (tar-header-size tokens))
722 (start (+ (tar-desc-data-start descriptor)
723 (- tar-header-offset (point-min))))
724 (end (+ start size)))
725 (let* ((tar-buffer (current-buffer))
726 (tarname (buffer-name))
727 (bufname (concat (file-name-nondirectory name)
731 (read-only-p (or buffer-read-only view-p))
732 (new-buffer-file-name (expand-file-name
733 ;; `:' is not allowed on Windows
734 (concat tarname "!" name)))
735 (buffer (get-file-buffer new-buffer-file-name))
740 (setq buffer (generate-new-buffer bufname))
741 (with-current-buffer buffer
742 (setq undo-list buffer-undo-list
744 (setq bufname (buffer-name buffer))
745 (setq just-created t)
748 (narrow-to-region start end)
750 (setq coding (or coding-system-for-read
751 (and set-auto-coding-function
752 (funcall set-auto-coding-function
754 ;; The following binding causes
755 ;; find-buffer-file-type-coding-system
756 ;; (defined on dos-w32.el) to act as if
757 ;; the file being extracted existed, so
758 ;; that the file's contents' encoding and
759 ;; EOL format are auto-detected.
760 (let ((file-name-handler-alist
761 '(("" . tar-file-name-handler))))
762 (car (find-operation-coding-system
763 'insert-file-contents
764 (cons name (current-buffer)) t)))))
766 (eq (coding-system-type coding) 'undecided))
767 (setq coding (detect-coding-region start end t)))
768 (if (and default-enable-multibyte-characters
769 (coding-system-get coding :for-unibyte))
770 (with-current-buffer buffer
771 (set-buffer-multibyte nil)))
773 (decode-coding-region start end coding buffer)
774 (with-current-buffer buffer
775 (goto-char (point-min))
776 (setq buffer-file-name new-buffer-file-name)
777 (setq buffer-file-truename
778 (abbreviate-file-name buffer-file-name))
779 ;; Force buffer-file-coding-system to what
780 ;; decode-coding-region actually used.
781 (set-buffer-file-coding-system last-coding-system-used t)
782 ;; Set the default-directory to the dir of the
784 (setq default-directory
785 (with-current-buffer tar-buffer
787 (normal-mode) ; pick a mode.
788 (rename-buffer bufname)
789 (make-local-variable 'tar-superior-buffer)
790 (make-local-variable 'tar-superior-descriptor)
791 (setq tar-superior-buffer tar-buffer)
792 (setq tar-superior-descriptor descriptor)
793 (setq buffer-read-only read-only-p)
794 (set-buffer-modified-p nil)
795 (setq buffer-undo-list undo-list)
796 (tar-subfile-mode 1))
797 (set-buffer tar-buffer))
798 (narrow-to-region (point-min) tar-header-offset)
802 buffer (and just-created 'kill-buffer-if-not-modified))
803 (if (eq other-window-p 'display)
804 (display-buffer buffer)
806 (switch-to-buffer-other-window buffer)
807 (switch-to-buffer buffer)))))))
810 (defun tar-extract-other-window ()
811 "In Tar mode, find this entry of the tar file in another window."
815 (defun tar-display-other-window ()
816 "In Tar mode, display this entry of the tar file in another window."
818 (tar-extract 'display))
821 "In Tar mode, view the tar file entry on this line."
826 (defun tar-read-file-name (&optional prompt)
827 "Read a file name with this line's entry as the default."
828 (or prompt (setq prompt "Copy to: "))
829 (let* ((default-file (expand-file-name
830 (tar-header-name (tar-desc-tokens
831 (tar-current-descriptor)))))
832 (target (expand-file-name
833 (read-file-name prompt
834 (file-name-directory default-file)
836 (if (or (string= "" (file-name-nondirectory target))
837 (file-directory-p target))
838 (setq target (concat (if (string-match "/$" target)
839 (substring target 0 (1- (match-end 0)))
842 (file-name-nondirectory default-file))))
846 (defun tar-copy (&optional to-file)
847 "In Tar mode, extract this entry of the tar file into a file on disk.
848 If TO-FILE is not supplied, it is prompted for, defaulting to the name of
849 the current tar-entry."
850 (interactive (list (tar-read-file-name)))
851 (let* ((descriptor (tar-get-descriptor))
852 (tokens (tar-desc-tokens descriptor))
853 (name (tar-header-name tokens))
854 (size (tar-header-size tokens))
855 (start (+ (tar-desc-data-start descriptor)
856 (- tar-header-offset (point-min))))
858 (inhibit-file-name-handlers inhibit-file-name-handlers)
859 (inhibit-file-name-operation inhibit-file-name-operation))
862 ;; Inhibit compressing a subfile again if *both* name and
863 ;; to-file are handled by jka-compr
864 (if (and (eq (find-file-name-handler name 'write-region) 'jka-compr-handler)
865 (eq (find-file-name-handler to-file 'write-region) 'jka-compr-handler))
866 (setq inhibit-file-name-handlers
867 (cons 'jka-compr-handler
868 (and (eq inhibit-file-name-operation 'write-region)
869 inhibit-file-name-handlers))
870 inhibit-file-name-operation 'write-region))
871 (let ((coding-system-for-write 'no-conversion))
872 (write-region start end to-file nil nil nil t)))
873 (message "Copied tar entry %s to %s" name to-file)))
875 (defun tar-flag-deleted (p &optional unflag)
876 "In Tar mode, mark this sub-file to be deleted from the tar file.
877 With a prefix argument, mark that many files."
881 (if (tar-current-descriptor unflag) ; barf if we're not on an entry-line.
884 (insert (if unflag " " "D"))))
885 (forward-line (if (< p 0) -1 1)))
886 (if (eobp) nil (forward-char 36)))
888 (defun tar-unflag (p)
889 "In Tar mode, un-mark this sub-file if it is marked to be deleted.
890 With a prefix argument, un-mark that many files forward."
892 (tar-flag-deleted p t))
894 (defun tar-unflag-backwards (p)
895 "In Tar mode, un-mark this sub-file if it is marked to be deleted.
896 With a prefix argument, un-mark that many files backward."
898 (tar-flag-deleted (- p) t))
901 (defun tar-expunge-internal ()
902 "Expunge the tar-entry specified by the current line."
903 (let* ((descriptor (tar-current-descriptor))
904 (tokens (tar-desc-tokens descriptor))
905 ;; (line (tar-desc-data-start descriptor))
906 (name (tar-header-name tokens))
907 (size (tar-header-size tokens))
908 (link-p (tar-header-link-type tokens))
909 (start (tar-desc-data-start descriptor))
910 (following-descs (cdr (memq descriptor tar-parse-info))))
911 (if link-p (setq size 0)) ; size lies for hard-links.
913 ;; delete the current line...
915 (let ((line-start (point)))
916 (end-of-line) (forward-char)
917 ;; decrement the header-pointer to be in sync...
918 (setq tar-header-offset (- tar-header-offset (- (point) line-start)))
919 (delete-region line-start (point)))
921 ;; delete the data pointer...
922 (setq tar-parse-info (delq descriptor tar-parse-info))
924 ;; delete the data from inside the file...
926 (let* ((data-start (+ start (- tar-header-offset (point-min)) -512))
927 (data-end (+ data-start 512 (ash (ash (+ size 511) -9) 9))))
928 (delete-region data-start data-end)
930 ;; and finally, decrement the start-pointers of all following
931 ;; entries in the archive. This is a pig when deleting a bunch
932 ;; of files at once - we could optimize this to only do the
933 ;; iteration over the files that remain, or only iterate up to
934 ;; the next file to be deleted.
935 (let ((data-length (- data-end data-start)))
936 (dolist (desc following-descs)
937 (tar-setf (tar-desc-data-start desc)
938 (- (tar-desc-data-start desc) data-length))))
940 (narrow-to-region (point-min) tar-header-offset))
943 (defun tar-expunge (&optional noconfirm)
944 "In Tar mode, delete all the archived files flagged for deletion.
945 This does not modify the disk image; you must save the tar file itself
946 for this to be permanent."
949 (y-or-n-p "Expunge files marked for deletion? "))
952 (goto-char (point-min))
955 (progn (tar-expunge-internal)
958 ;; after doing the deletions, add any padding that may be necessary.
959 (tar-pad-to-blocksize)
960 (narrow-to-region (point-min) tar-header-offset))
962 (message "Nothing to expunge.")
963 (message "%s files expunged. Be sure to save this buffer." n)))))
966 (defun tar-clear-modification-flags ()
967 "Remove the stars at the beginning of each line."
970 (goto-char (point-min))
971 (while (< (point) tar-header-offset)
972 (if (not (eq (following-char) ?\s))
973 (progn (delete-char 1) (insert " ")))
977 (defun tar-chown-entry (new-uid)
978 "Change the user-id associated with this entry in the tar file.
979 If this tar file was written by GNU tar, then you will be able to edit
980 the user id as a string; otherwise, you must edit it as a number.
981 You can force editing as a number by calling this with a prefix arg.
982 This does not modify the disk image; you must save the tar file itself
983 for this to be permanent."
985 (let ((tokens (tar-desc-tokens (tar-current-descriptor))))
986 (if (or current-prefix-arg
987 (not (tar-header-magic tokens)))
989 (while (not (numberp (setq n (read-minibuffer
991 (format "%s" (tar-header-uid tokens)))))))
993 (read-string "New UID string: " (tar-header-uname tokens))))))
994 (cond ((stringp new-uid)
995 (tar-setf (tar-header-uname (tar-desc-tokens (tar-current-descriptor)))
997 (tar-alter-one-field tar-uname-offset (concat new-uid "\000")))
999 (tar-setf (tar-header-uid (tar-desc-tokens (tar-current-descriptor)))
1001 (tar-alter-one-field tar-uid-offset
1002 (concat (substring (format "%6o" new-uid) 0 6) "\000 ")))))
1005 (defun tar-chgrp-entry (new-gid)
1006 "Change the group-id associated with this entry in the tar file.
1007 If this tar file was written by GNU tar, then you will be able to edit
1008 the group id as a string; otherwise, you must edit it as a number.
1009 You can force editing as a number by calling this with a prefix arg.
1010 This does not modify the disk image; you must save the tar file itself
1011 for this to be permanent."
1013 (let ((tokens (tar-desc-tokens (tar-current-descriptor))))
1014 (if (or current-prefix-arg
1015 (not (tar-header-magic tokens)))
1017 (while (not (numberp (setq n (read-minibuffer
1019 (format "%s" (tar-header-gid tokens)))))))
1021 (read-string "New GID string: " (tar-header-gname tokens))))))
1022 (cond ((stringp new-gid)
1023 (tar-setf (tar-header-gname (tar-desc-tokens (tar-current-descriptor)))
1025 (tar-alter-one-field tar-gname-offset
1026 (concat new-gid "\000")))
1028 (tar-setf (tar-header-gid (tar-desc-tokens (tar-current-descriptor)))
1030 (tar-alter-one-field tar-gid-offset
1031 (concat (substring (format "%6o" new-gid) 0 6) "\000 ")))))
1033 (defun tar-rename-entry (new-name)
1034 "Change the name associated with this entry in the tar file.
1035 This does not modify the disk image; you must save the tar file itself
1036 for this to be permanent."
1038 (list (read-string "New name: "
1039 (tar-header-name (tar-desc-tokens (tar-current-descriptor))))))
1040 (if (string= "" new-name) (error "zero length name"))
1041 (let ((encoded-new-name (encode-coding-string new-name
1042 tar-file-name-coding-system)))
1043 (if (> (length encoded-new-name) 98) (error "name too long"))
1044 (tar-setf (tar-header-name (tar-desc-tokens (tar-current-descriptor)))
1046 (tar-alter-one-field 0
1047 (substring (concat encoded-new-name (make-string 99 0)) 0 99))))
1050 (defun tar-chmod-entry (new-mode)
1051 "Change the protection bits associated with this entry in the tar file.
1052 This does not modify the disk image; you must save the tar file itself
1053 for this to be permanent."
1054 (interactive (list (tar-parse-octal-integer-safe
1055 (read-string "New protection (octal): "))))
1056 (tar-setf (tar-header-mode (tar-desc-tokens (tar-current-descriptor)))
1058 (tar-alter-one-field tar-mode-offset
1059 (concat (substring (format "%6o" new-mode) 0 6) "\000 ")))
1062 (defun tar-alter-one-field (data-position new-data-string)
1063 (let* ((descriptor (tar-current-descriptor))
1064 (tokens (tar-desc-tokens descriptor)))
1068 ;; update the header-line.
1072 (delete-region p (point))
1073 (insert (tar-header-block-summarize tokens) "\n")
1074 (setq tar-header-offset (point-max)))
1077 (let* ((start (+ (tar-desc-data-start descriptor)
1078 (- tar-header-offset (point-min))
1081 ;; delete the old field and insert a new one.
1082 (goto-char (+ start data-position))
1083 (delete-region (point) (+ (point) (length new-data-string))) ; <--
1085 ;; As new-data-string is unibyte, just inserting it will
1086 ;; make eight-bit chars to the corresponding multibyte
1087 ;; chars. This avoid that conversion, i.e., eight-bit
1088 ;; chars are converted to multibyte form of eight-bit
1090 (insert (string-to-multibyte new-data-string))
1092 ;; compute a new checksum and insert it.
1093 (let ((chk (tar-header-block-checksum
1094 (buffer-substring start (+ start 512)))))
1095 (goto-char (+ start tar-chk-offset))
1096 (delete-region (point) (+ (point) 8))
1097 (insert (format "%6o" chk))
1100 (tar-setf (tar-header-checksum tokens) chk)
1102 ;; ok, make sure we didn't botch it.
1103 (tar-header-block-check-checksum
1104 (buffer-substring start (+ start 512))
1105 chk (tar-header-name tokens))
1107 (narrow-to-region (point-min) tar-header-offset)
1108 (tar-next-line 0))))
1111 (defun tar-octal-time (timeval)
1112 ;; Format a timestamp as 11 octal digits. Ghod, I hope this works...
1113 (let ((hibits (car timeval)) (lobits (car (cdr timeval))))
1114 (format "%05o%01o%05o"
1116 (logior (lsh (logand 3 hibits) 1)
1117 (if (> (logand lobits 32768) 0) 1 0))
1118 (logand 32767 lobits)
1121 (defun tar-subfile-save-buffer ()
1122 "In tar subfile mode, save this buffer into its parent tar-file buffer.
1123 This doesn't write anything to disk; you must save the parent tar-file buffer
1124 to make your changes permanent."
1126 (if (not (and (boundp 'tar-superior-buffer) tar-superior-buffer))
1127 (error "This buffer has no superior tar file buffer"))
1128 (if (not (and (boundp 'tar-superior-descriptor) tar-superior-descriptor))
1129 (error "This buffer doesn't have an index into its superior tar file!"))
1131 (let ((subfile (current-buffer))
1132 (coding buffer-file-coding-system)
1133 (descriptor tar-superior-descriptor)
1135 (set-buffer tar-superior-buffer)
1136 (let* ((tokens (tar-desc-tokens descriptor))
1137 (start (tar-desc-data-start descriptor))
1138 (name (tar-header-name tokens))
1139 (size (tar-header-size tokens))
1140 (size-pad (ash (ash (+ size 511) -9) 9))
1141 (head (memq descriptor tar-parse-info))
1142 (following-descs (cdr head)))
1144 (error "Can't find this tar file entry in its parent tar file!"))
1147 ;; delete the old data...
1148 (let* ((data-start (+ start (- tar-header-offset (point-min))))
1149 (data-end (+ data-start (ash (ash (+ size 511) -9) 9))))
1150 (narrow-to-region data-start data-end)
1151 (delete-region (point-min) (point-max))
1152 ;; insert the new data...
1153 (goto-char data-start)
1154 (with-current-buffer subfile
1157 (encode-coding-region 1 (point-max) coding tar-superior-buffer)))
1158 (setq subfile-size (- (point-max) (point-min)))
1160 ;; pad the new data out to a multiple of 512...
1161 (let ((subfile-size-pad (ash (ash (+ subfile-size 511) -9) 9)))
1162 (goto-char (point-max))
1163 (insert (make-string (- subfile-size-pad subfile-size) 0))
1165 ;; update the data pointer of this and all following files...
1166 (tar-setf (tar-header-size tokens) subfile-size)
1167 (let ((difference (- subfile-size-pad size-pad)))
1168 (dolist (desc following-descs)
1169 (tar-setf (tar-desc-data-start desc)
1170 (+ (tar-desc-data-start desc) difference))))
1172 ;; Update the size field in the header block.
1174 (let ((header-start (- data-start 512)))
1175 (goto-char (+ header-start tar-size-offset))
1176 (delete-region (point) (+ (point) 12))
1177 (insert (format "%11o" subfile-size))
1180 ;; Maybe update the datestamp.
1181 (if (not tar-update-datestamp)
1183 (goto-char (+ header-start tar-time-offset))
1184 (delete-region (point) (+ (point) 12))
1185 (insert (tar-octal-time (current-time)))
1188 ;; compute a new checksum and insert it.
1189 (let ((chk (tar-header-block-checksum
1190 (buffer-substring header-start data-start))))
1191 (goto-char (+ header-start tar-chk-offset))
1192 (delete-region (point) (+ (point) 8))
1193 (insert (format "%6o" chk))
1196 (tar-setf (tar-header-checksum tokens) chk)))
1198 ;; alter the descriptor-line...
1200 (let ((position (- (length tar-parse-info) (length head))))
1201 (goto-char (point-min))
1202 (forward-line position)
1206 (m (set-marker (make-marker) tar-header-offset)))
1208 (setq after (point))
1209 ;; Insert the new text after the old, before deleting,
1210 ;; to preserve the window start.
1211 (let ((line (tar-header-block-summarize tokens t)))
1212 (insert-before-markers line "\n"))
1213 (delete-region p after)
1214 (setq tar-header-offset (marker-position m)))
1216 ;; after doing the insertion, add any final padding that may be necessary.
1217 (tar-pad-to-blocksize))
1218 (narrow-to-region (point-min) tar-header-offset)))
1219 (set-buffer-modified-p t) ; mark the tar file as modified
1221 (set-buffer subfile)
1222 (set-buffer-modified-p nil) ; mark the tar subfile as unmodified
1223 (message "Saved into tar-buffer `%s'. Be sure to save that buffer!"
1224 (buffer-name tar-superior-buffer))
1225 ;; Prevent basic-save-buffer from changing our coding-system.
1226 (setq last-coding-system-used buffer-file-coding-system)
1227 ;; Prevent ordinary saving from happening.
1231 ;; When this function is called, it is sure that the buffer is unibyte.
1232 (defun tar-pad-to-blocksize ()
1233 "If we are being anal about tar file blocksizes, fix up the current buffer.
1234 Leaves the region wide."
1235 (if (null tar-anal-blocksize)
1238 (let* ((last-desc (nth (1- (length tar-parse-info)) tar-parse-info))
1239 (start (tar-desc-data-start last-desc))
1240 (tokens (tar-desc-tokens last-desc))
1241 (link-p (tar-header-link-type tokens))
1242 (size (if link-p 0 (tar-header-size tokens)))
1243 (data-end (+ start size))
1244 (bbytes (ash tar-anal-blocksize 9))
1245 (pad-to (+ bbytes (* bbytes (/ (- data-end (point-min)) bbytes))))
1246 (inhibit-read-only t) ; ##
1248 ;; If the padding after the last data is too long, delete some;
1249 ;; else insert some until we are padded out to the right number of blocks.
1251 (let ((goal-end (+ (or tar-header-offset 0) pad-to)))
1252 (if (> (point-max) goal-end)
1253 (delete-region goal-end (point-max))
1254 (goto-char (point-max))
1255 (insert (make-string (- goal-end (point-max)) ?\0)))))))
1258 ;; Used in write-file-hook to write tar-files out correctly.
1259 (defun tar-mode-write-file ()
1263 ;; Doing this here confuses things - the region gets left too wide!
1264 ;; I suppose this is run in a context where changing the buffer is bad.
1265 ;; (tar-pad-to-blocksize)
1266 ;; tar-header-offset turns out to be null for files fetched with W3,
1268 (let ((coding-system-for-write 'no-conversion))
1269 (write-region (or tar-header-offset
1272 buffer-file-name nil t))
1273 (tar-clear-modification-flags)
1274 (set-buffer-modified-p nil))
1275 (narrow-to-region (point-min) tar-header-offset))
1276 ;; Return t because we've written the file.
1281 ;; arch-tag: 8a585a4a-340e-42c2-89e7-d3b1013a4b78
1282 ;;; tar-mode.el ends here