1;;; tar-mode.el --- simple editing of tar files from GNU emacs 2 3;; Copyright (C) 1990, 1991, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 4;; 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007 Free Software Foundation, Inc. 5 6;; Author: Jamie Zawinski <jwz@lucid.com> 7;; Maintainer: FSF 8;; Created: 04 Apr 1990 9;; Keywords: unix 10 11;; This file is part of GNU Emacs. 12 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 2, or (at your option) 16;; any later version. 17 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. 22 23;; You should have received a copy of the GNU General Public License 24;; along with GNU Emacs; see the file COPYING. If not, write to the 25;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, 26;; Boston, MA 02110-1301, USA. 27 28;;; Commentary: 29 30;; This package attempts to make dealing with Unix 'tar' archives easier. 31;; When this code is loaded, visiting a file whose name ends in '.tar' will 32;; cause the contents of that archive file to be displayed in a Dired-like 33;; listing. It is then possible to use the customary Dired keybindings to 34;; extract sub-files from that archive, either by reading them into their own 35;; editor buffers, or by copying them directly to arbitrary files on disk. 36;; It is also possible to delete sub-files from within the tar file and write 37;; the modified archive back to disk, or to edit sub-files within the archive 38;; and re-insert the modified files into the archive. See the documentation 39;; string of tar-mode for more info. 40 41;; This code now understands the extra fields that GNU tar adds to tar files. 42 43;; This interacts correctly with "uncompress.el" in the Emacs library, 44;; which you get with 45;; 46;; (autoload 'uncompress-while-visiting "uncompress") 47;; (setq auto-mode-alist (cons '("\\.Z$" . uncompress-while-visiting) 48;; auto-mode-alist)) 49;; 50;; Do not attempt to use tar-mode.el with crypt.el, you will lose. 51 52;; *************** TO DO *************** 53;; 54;; o chmod should understand "a+x,og-w". 55;; 56;; o It's not possible to add a NEW file to a tar archive; not that 57;; important, but still... 58;; 59;; o The code is less efficient that it could be - in a lot of places, I 60;; pull a 512-character string out of the buffer and parse it, when I could 61;; be parsing it in place, not garbaging a string. Should redo that. 62;; 63;; o I'd like a command that searches for a string/regexp in every subfile 64;; of an archive, where <esc> would leave you in a subfile-edit buffer. 65;; (Like the Meta-R command of the Zmacs mail reader.) 66;; 67;; o Sometimes (but not always) reverting the tar-file buffer does not 68;; re-grind the listing, and you are staring at the binary tar data. 69;; Typing 'g' again immediately after that will always revert and re-grind 70;; it, though. I have no idea why this happens. 71;; 72;; o Tar-mode interacts poorly with crypt.el and zcat.el because the tar 73;; write-file-hook actually writes the file. Instead it should remove the 74;; header (and conspire to put it back afterwards) so that other write-file 75;; hooks which frob the buffer have a chance to do their dirty work. There 76;; might be a problem if the tar write-file-hook does not come *first* on 77;; the list. 78;; 79;; o Block files, sparse files, continuation files, and the various header 80;; types aren't editable. Actually I don't know that they work at all. 81 82;; Rationale: 83 84;; Why does tar-mode edit the file itself instead of using tar? 85 86;; That means that you can edit tar files which you don't have room for 87;; on your local disk. 88 89;; I don't know about recent features in gnu tar, but old versions of tar 90;; can't replace a file in the middle of a tar file with a new version. 91;; Tar-mode can. I don't think tar can do things like chmod the subfiles. 92;; An implementation which involved unpacking and repacking the file into 93;; some scratch directory would be very wasteful, and wouldn't be able to 94;; preserve the file owners. 95 96;;; Code: 97 98(defgroup tar nil 99 "Simple editing of tar files." 100 :prefix "tar-" 101 :group 'data) 102 103(defcustom tar-anal-blocksize 20 104 "The blocksize of tar files written by Emacs, or nil, meaning don't care. 105The blocksize of a tar file is not really the size of the blocks; rather, it is 106the number of blocks written with one system call. When tarring to a tape, 107this is the size of the *tape* blocks, but when writing to a file, it doesn't 108matter much. The only noticeable difference is that if a tar file does not 109have a blocksize of 20, tar will tell you that; all this really controls is 110how many null padding bytes go on the end of the tar file." 111 :type '(choice integer (const nil)) 112 :group 'tar) 113 114(defcustom tar-update-datestamp nil 115 "Non-nil means Tar mode should play fast and loose with sub-file datestamps. 116If this is true, then editing and saving a tar file entry back into its 117tar file will update its datestamp. If false, the datestamp is unchanged. 118You may or may not want this - it is good in that you can tell when a file 119in a tar archive has been changed, but it is bad for the same reason that 120editing a file in the tar archive at all is bad - the changed version of 121the file never exists on disk." 122 :type 'boolean 123 :group 'tar) 124 125(defcustom tar-mode-show-date nil 126 "Non-nil means Tar mode should show the date/time of each subfile. 127This information is useful, but it takes screen space away from file names." 128 :type 'boolean 129 :group 'tar) 130 131(defvar tar-parse-info nil) 132;; Be sure that this variable holds byte position, not char position. 133(defvar tar-header-offset nil) 134(defvar tar-superior-buffer nil) 135(defvar tar-superior-descriptor nil) 136(defvar tar-subfile-mode nil) 137 138(put 'tar-parse-info 'permanent-local t) 139(put 'tar-header-offset 'permanent-local t) 140(put 'tar-superior-buffer 'permanent-local t) 141(put 'tar-superior-descriptor 'permanent-local t) 142 143(defmacro tar-setf (form val) 144 "A mind-numbingly simple implementation of setf." 145 (let ((mform (macroexpand form (and (boundp 'byte-compile-macro-environment) 146 byte-compile-macro-environment)))) 147 (cond ((symbolp mform) (list 'setq mform val)) 148 ((not (consp mform)) (error "can't setf %s" form)) 149 ((eq (car mform) 'aref) 150 (list 'aset (nth 1 mform) (nth 2 mform) val)) 151 ((eq (car mform) 'car) 152 (list 'setcar (nth 1 mform) val)) 153 ((eq (car mform) 'cdr) 154 (list 'setcdr (nth 1 mform) val)) 155 (t (error "don't know how to setf %s" form))))) 156 157;;; down to business. 158 159(defmacro make-tar-header (name mode uid git size date ck lt ln 160 magic uname gname devmaj devmin) 161 (list 'vector name mode uid git size date ck lt ln 162 magic uname gname devmaj devmin)) 163 164(defmacro tar-header-name (x) (list 'aref x 0)) 165(defmacro tar-header-mode (x) (list 'aref x 1)) 166(defmacro tar-header-uid (x) (list 'aref x 2)) 167(defmacro tar-header-gid (x) (list 'aref x 3)) 168(defmacro tar-header-size (x) (list 'aref x 4)) 169(defmacro tar-header-date (x) (list 'aref x 5)) 170(defmacro tar-header-checksum (x) (list 'aref x 6)) 171(defmacro tar-header-link-type (x) (list 'aref x 7)) 172(defmacro tar-header-link-name (x) (list 'aref x 8)) 173(defmacro tar-header-magic (x) (list 'aref x 9)) 174(defmacro tar-header-uname (x) (list 'aref x 10)) 175(defmacro tar-header-gname (x) (list 'aref x 11)) 176(defmacro tar-header-dmaj (x) (list 'aref x 12)) 177(defmacro tar-header-dmin (x) (list 'aref x 13)) 178 179(defmacro make-tar-desc (data-start tokens) 180 (list 'cons data-start tokens)) 181 182(defmacro tar-desc-data-start (x) (list 'car x)) 183(defmacro tar-desc-tokens (x) (list 'cdr x)) 184 185(defconst tar-name-offset 0) 186(defconst tar-mode-offset (+ tar-name-offset 100)) 187(defconst tar-uid-offset (+ tar-mode-offset 8)) 188(defconst tar-gid-offset (+ tar-uid-offset 8)) 189(defconst tar-size-offset (+ tar-gid-offset 8)) 190(defconst tar-time-offset (+ tar-size-offset 12)) 191(defconst tar-chk-offset (+ tar-time-offset 12)) 192(defconst tar-linkp-offset (+ tar-chk-offset 8)) 193(defconst tar-link-offset (+ tar-linkp-offset 1)) 194;;; GNU-tar specific slots. 195(defconst tar-magic-offset (+ tar-link-offset 100)) 196(defconst tar-uname-offset (+ tar-magic-offset 8)) 197(defconst tar-gname-offset (+ tar-uname-offset 32)) 198(defconst tar-dmaj-offset (+ tar-gname-offset 32)) 199(defconst tar-dmin-offset (+ tar-dmaj-offset 8)) 200(defconst tar-end-offset (+ tar-dmin-offset 8)) 201 202(defun tar-header-block-tokenize (string) 203 "Return a `tar-header' structure. 204This is a list of name, mode, uid, gid, size, 205write-date, checksum, link-type, and link-name." 206 (cond ((< (length string) 512) nil) 207 (;(some 'plusp string) ; <-- oops, massive cycle hog! 208 (or (not (= 0 (aref string 0))) ; This will do. 209 (not (= 0 (aref string 101)))) 210 (let* ((name-end (1- tar-mode-offset)) 211 (link-end (1- tar-magic-offset)) 212 (uname-end (1- tar-gname-offset)) 213 (gname-end (1- tar-dmaj-offset)) 214 (link-p (aref string tar-linkp-offset)) 215 (magic-str (substring string tar-magic-offset (1- tar-uname-offset))) 216 (uname-valid-p (or (string= "ustar " magic-str) (string= "GNUtar " magic-str))) 217 name linkname 218 (nulsexp "[^\000]*\000")) 219 (when (string-match nulsexp string tar-name-offset) 220 (setq name-end (min name-end (1- (match-end 0))))) 221 (when (string-match nulsexp string tar-link-offset) 222 (setq link-end (min link-end (1- (match-end 0))))) 223 (when (string-match nulsexp string tar-uname-offset) 224 (setq uname-end (min uname-end (1- (match-end 0))))) 225 (when (string-match nulsexp string tar-gname-offset) 226 (setq gname-end (min gname-end (1- (match-end 0))))) 227 (setq name (substring string tar-name-offset name-end) 228 link-p (if (or (= link-p 0) (= link-p ?0)) 229 nil 230 (- link-p ?0))) 231 (setq linkname (substring string tar-link-offset link-end)) 232 (if default-enable-multibyte-characters 233 (setq name 234 (decode-coding-string name 235 (or file-name-coding-system 236 default-file-name-coding-system 237 'undecided)) 238 linkname 239 (decode-coding-string linkname 240 (or file-name-coding-system 241 default-file-name-coding-system 242 'undecided)))) 243 (if (and (null link-p) (string-match "/\\'" name)) (setq link-p 5)) ; directory 244 (make-tar-header 245 name 246 (tar-parse-octal-integer string tar-mode-offset tar-uid-offset) 247 (tar-parse-octal-integer string tar-uid-offset tar-gid-offset) 248 (tar-parse-octal-integer string tar-gid-offset tar-size-offset) 249 (tar-parse-octal-integer string tar-size-offset tar-time-offset) 250 (tar-parse-octal-long-integer string tar-time-offset tar-chk-offset) 251 (tar-parse-octal-integer string tar-chk-offset tar-linkp-offset) 252 link-p 253 linkname 254 uname-valid-p 255 (and uname-valid-p (substring string tar-uname-offset uname-end)) 256 (and uname-valid-p (substring string tar-gname-offset gname-end)) 257 (tar-parse-octal-integer string tar-dmaj-offset tar-dmin-offset) 258 (tar-parse-octal-integer string tar-dmin-offset tar-end-offset) 259 ))) 260 (t 'empty-tar-block))) 261 262 263(defun tar-parse-octal-integer (string &optional start end) 264 (if (null start) (setq start 0)) 265 (if (null end) (setq end (length string))) 266 (if (= (aref string start) 0) 267 0 268 (let ((n 0)) 269 (while (< start end) 270 (setq n (if (< (aref string start) ?0) n 271 (+ (* n 8) (- (aref string start) ?0))) 272 start (1+ start))) 273 n))) 274 275(defun tar-parse-octal-long-integer (string &optional start end) 276 (if (null start) (setq start 0)) 277 (if (null end) (setq end (length string))) 278 (if (= (aref string start) 0) 279 (list 0 0) 280 (let ((lo 0) 281 (hi 0)) 282 (while (< start end) 283 (if (>= (aref string start) ?0) 284 (setq lo (+ (* lo 8) (- (aref string start) ?0)) 285 hi (+ (* hi 8) (ash lo -16)) 286 lo (logand lo 65535))) 287 (setq start (1+ start))) 288 (list hi lo)))) 289 290(defun tar-parse-octal-integer-safe (string) 291 (if (zerop (length string)) (error "empty string")) 292 (mapc (lambda (c) 293 (if (or (< c ?0) (> c ?7)) 294 (error "`%c' is not an octal digit" c))) 295 string) 296 (tar-parse-octal-integer string)) 297 298 299(defun tar-header-block-checksum (string) 300 "Compute and return a tar-acceptable checksum for this block." 301 (let* ((chk-field-start tar-chk-offset) 302 (chk-field-end (+ chk-field-start 8)) 303 (sum 0) 304 (i 0)) 305 ;; Add up all of the characters except the ones in the checksum field. 306 ;; Add that field as if it were filled with spaces. 307 (while (< i chk-field-start) 308 (setq sum (+ sum (aref string i)) 309 i (1+ i))) 310 (setq i chk-field-end) 311 (while (< i 512) 312 (setq sum (+ sum (aref string i)) 313 i (1+ i))) 314 (+ sum (* 32 8)))) 315 316(defun tar-header-block-check-checksum (hblock desired-checksum file-name) 317 "Beep and print a warning if the checksum doesn't match." 318 (if (not (= desired-checksum (tar-header-block-checksum hblock))) 319 (progn (beep) (message "Invalid checksum for file %s!" file-name)))) 320 321(defun tar-clip-time-string (time) 322 (let ((str (current-time-string time))) 323 (concat " " (substring str 4 16) (substring str 19 24)))) 324 325(defun tar-grind-file-mode (mode) 326 "Construct a `-rw--r--r--' string indicating MODE. 327MODE should be an integer which is a file mode value." 328 (string 329 (if (zerop (logand 256 mode)) ?- ?r) 330 (if (zerop (logand 128 mode)) ?- ?w) 331 (if (zerop (logand 1024 mode)) (if (zerop (logand 64 mode)) ?- ?x) ?s) 332 (if (zerop (logand 32 mode)) ?- ?r) 333 (if (zerop (logand 16 mode)) ?- ?w) 334 (if (zerop (logand 2048 mode)) (if (zerop (logand 8 mode)) ?- ?x) ?s) 335 (if (zerop (logand 4 mode)) ?- ?r) 336 (if (zerop (logand 2 mode)) ?- ?w) 337 (if (zerop (logand 1 mode)) ?- ?x))) 338 339(defun tar-header-block-summarize (tar-hblock &optional mod-p) 340 "Return a line similar to the output of `tar -vtf'." 341 (let ((name (tar-header-name tar-hblock)) 342 (mode (tar-header-mode tar-hblock)) 343 (uid (tar-header-uid tar-hblock)) 344 (gid (tar-header-gid tar-hblock)) 345 (uname (tar-header-uname tar-hblock)) 346 (gname (tar-header-gname tar-hblock)) 347 (size (tar-header-size tar-hblock)) 348 (time (tar-header-date tar-hblock)) 349 ;; (ck (tar-header-checksum tar-hblock)) 350 (type (tar-header-link-type tar-hblock)) 351 (link-name (tar-header-link-name tar-hblock))) 352 (format "%c%c%s%8s/%-8s%7s%s %s%s" 353 (if mod-p ?* ? ) 354 (cond ((or (eq type nil) (eq type 0)) ?-) 355 ((eq type 1) ?h) ; link 356 ((eq type 2) ?l) ; symlink 357 ((eq type 3) ?c) ; char special 358 ((eq type 4) ?b) ; block special 359 ((eq type 5) ?d) ; directory 360 ((eq type 6) ?p) ; FIFO/pipe 361 ((eq type 20) ?*) ; directory listing 362 ((eq type 28) ?L) ; next has longname 363 ((eq type 29) ?M) ; multivolume continuation 364 ((eq type 35) ?S) ; sparse 365 ((eq type 38) ?V) ; volume header 366 (t ?\s) 367 ) 368 (tar-grind-file-mode mode) 369 (if (= 0 (length uname)) uid uname) 370 (if (= 0 (length gname)) gid gname) 371 size 372 (if tar-mode-show-date (tar-clip-time-string time) "") 373 (propertize name 374 'mouse-face 'highlight 375 'help-echo "mouse-2: extract this file into a buffer") 376 (if (or (eq type 1) (eq type 2)) 377 (concat (if (= type 1) " ==> " " --> ") link-name) 378 "")))) 379 380(defun tar-untar-buffer () 381 "Extract all archive members in the tar-file into the current directory." 382 (interactive) 383 (let ((multibyte enable-multibyte-characters)) 384 (unwind-protect 385 (save-restriction 386 (widen) 387 (set-buffer-multibyte nil) 388 (dolist (descriptor tar-parse-info) 389 (let* ((tokens (tar-desc-tokens descriptor)) 390 (name (tar-header-name tokens)) 391 (dir (file-name-directory name)) 392 (start (+ (tar-desc-data-start descriptor) 393 (- tar-header-offset (point-min)))) 394 (end (+ start (tar-header-size tokens)))) 395 (unless (file-directory-p name) 396 (message "Extracting %s" name) 397 (if (and dir (not (file-exists-p dir))) 398 (make-directory dir t)) 399 (unless (file-directory-p name) 400 (write-region start end name)) 401 (set-file-modes name (tar-header-mode tokens)))))) 402 (set-buffer-multibyte multibyte)))) 403 404(defun tar-summarize-buffer () 405 "Parse the contents of the tar file in the current buffer. 406Place a dired-like listing on the front; 407then narrow to it, so that only that listing 408is visible (and the real data of the buffer is hidden)." 409 (let ((modified (buffer-modified-p))) 410 (set-buffer-multibyte nil) 411 (let* ((result '()) 412 (pos (point-min)) 413 (progress-reporter 414 (make-progress-reporter "Parsing tar file..." 415 (point-min) (max 1 (- (buffer-size) 1024)))) 416 tokens) 417 (while (and (<= (+ pos 512) (point-max)) 418 (not (eq 'empty-tar-block 419 (setq tokens 420 (tar-header-block-tokenize 421 (buffer-substring pos (+ pos 512))))))) 422 (setq pos (+ pos 512)) 423 (progress-reporter-update progress-reporter pos) 424 (if (eq (tar-header-link-type tokens) 20) 425 ;; Foo. There's an extra empty block after these. 426 (setq pos (+ pos 512))) 427 (let ((size (tar-header-size tokens))) 428 (if (< size 0) 429 (error "%s has size %s - corrupted" 430 (tar-header-name tokens) size)) 431 ; 432 ; This is just too slow. Don't really need it anyway.... 433 ;(tar-header-block-check-checksum 434 ; hblock (tar-header-block-checksum hblock) 435 ; (tar-header-name tokens)) 436 437 (push (make-tar-desc pos tokens) result) 438 439 (and (null (tar-header-link-type tokens)) 440 (> size 0) 441 (setq pos 442 (+ pos 512 (ash (ash (1- size) -9) 9)) ; this works 443 ;(+ pos (+ size (- 512 (rem (1- size) 512)))) ; this doesn't 444 )))) 445 (make-local-variable 'tar-parse-info) 446 (setq tar-parse-info (nreverse result)) 447 ;; A tar file should end with a block or two of nulls, 448 ;; but let's not get a fatal error if it doesn't. 449 (if (eq tokens 'empty-tar-block) 450 (progress-reporter-done progress-reporter) 451 (message "Warning: premature EOF parsing tar file"))) 452 (set-buffer-multibyte default-enable-multibyte-characters) 453 (goto-char (point-min)) 454 (let ((inhibit-read-only t)) 455 ;; Collect summary lines and insert them all at once since tar files 456 ;; can be pretty big. 457 (let ((total-summaries 458 (mapconcat 459 (lambda (tar-desc) 460 (tar-header-block-summarize (tar-desc-tokens tar-desc))) 461 tar-parse-info 462 "\n"))) 463 (insert total-summaries "\n")) 464 (narrow-to-region (point-min) (point)) 465 (set (make-local-variable 'tar-header-offset) (position-bytes (point))) 466 (goto-char (point-min)) 467 (restore-buffer-modified-p modified)))) 468 469(defvar tar-mode-map 470 (let ((map (make-keymap))) 471 (suppress-keymap map) 472 (define-key map " " 'tar-next-line) 473 (define-key map "C" 'tar-copy) 474 (define-key map "d" 'tar-flag-deleted) 475 (define-key map "\^D" 'tar-flag-deleted) 476 (define-key map "e" 'tar-extract) 477 (define-key map "f" 'tar-extract) 478 (define-key map "\C-m" 'tar-extract) 479 (define-key map [mouse-2] 'tar-mouse-extract) 480 (define-key map "g" 'revert-buffer) 481 (define-key map "h" 'describe-mode) 482 (define-key map "n" 'tar-next-line) 483 (define-key map "\^N" 'tar-next-line) 484 (define-key map [down] 'tar-next-line) 485 (define-key map "o" 'tar-extract-other-window) 486 (define-key map "p" 'tar-previous-line) 487 (define-key map "q" 'quit-window) 488 (define-key map "\^P" 'tar-previous-line) 489 (define-key map [up] 'tar-previous-line) 490 (define-key map "R" 'tar-rename-entry) 491 (define-key map "u" 'tar-unflag) 492 (define-key map "v" 'tar-view) 493 (define-key map "x" 'tar-expunge) 494 (define-key map "\177" 'tar-unflag-backwards) 495 (define-key map "E" 'tar-extract-other-window) 496 (define-key map "M" 'tar-chmod-entry) 497 (define-key map "G" 'tar-chgrp-entry) 498 (define-key map "O" 'tar-chown-entry) 499 500 ;; Make menu bar items. 501 502 ;; Get rid of the Edit menu bar item to save space. 503 (define-key map [menu-bar edit] 'undefined) 504 505 (define-key map [menu-bar immediate] 506 (cons "Immediate" (make-sparse-keymap "Immediate"))) 507 508 (define-key map [menu-bar immediate view] 509 '("View This File" . tar-view)) 510 (define-key map [menu-bar immediate display] 511 '("Display in Other Window" . tar-display-other-window)) 512 (define-key map [menu-bar immediate find-file-other-window] 513 '("Find in Other Window" . tar-extract-other-window)) 514 (define-key map [menu-bar immediate find-file] 515 '("Find This File" . tar-extract)) 516 517 (define-key map [menu-bar mark] 518 (cons "Mark" (make-sparse-keymap "Mark"))) 519 520 (define-key map [menu-bar mark unmark-all] 521 '("Unmark All" . tar-clear-modification-flags)) 522 (define-key map [menu-bar mark deletion] 523 '("Flag" . tar-flag-deleted)) 524 (define-key map [menu-bar mark unmark] 525 '("Unflag" . tar-unflag)) 526 527 (define-key map [menu-bar operate] 528 (cons "Operate" (make-sparse-keymap "Operate"))) 529 530 (define-key map [menu-bar operate chown] 531 '("Change Owner..." . tar-chown-entry)) 532 (define-key map [menu-bar operate chgrp] 533 '("Change Group..." . tar-chgrp-entry)) 534 (define-key map [menu-bar operate chmod] 535 '("Change Mode..." . tar-chmod-entry)) 536 (define-key map [menu-bar operate rename] 537 '("Rename to..." . tar-rename-entry)) 538 (define-key map [menu-bar operate copy] 539 '("Copy to..." . tar-copy)) 540 (define-key map [menu-bar operate expunge] 541 '("Expunge Marked Files" . tar-expunge)) 542 543 map) 544 "Local keymap for Tar mode listings.") 545 546 547;; tar mode is suitable only for specially formatted data. 548(put 'tar-mode 'mode-class 'special) 549(put 'tar-subfile-mode 'mode-class 'special) 550 551;;;###autoload 552(define-derived-mode tar-mode nil "Tar" 553 "Major mode for viewing a tar file as a dired-like listing of its contents. 554You can move around using the usual cursor motion commands. 555Letters no longer insert themselves. 556Type `e' to pull a file out of the tar file and into its own buffer; 557or click mouse-2 on the file's line in the Tar mode buffer. 558Type `c' to copy an entry from the tar file into another file on disk. 559 560If you edit a sub-file of this archive (as with the `e' command) and 561save it with \\[save-buffer], the contents of that buffer will be 562saved back into the tar-file buffer; in this way you can edit a file 563inside of a tar archive without extracting it and re-archiving it. 564 565See also: variables `tar-update-datestamp' and `tar-anal-blocksize'. 566\\{tar-mode-map}" 567 ;; this is not interactive because you shouldn't be turning this 568 ;; mode on and off. You can corrupt things that way. 569 ;; rms: with permanent locals, it should now be possible to make this work 570 ;; interactively in some reasonable fashion. 571 (make-local-variable 'tar-header-offset) 572 (make-local-variable 'tar-parse-info) 573 (set (make-local-variable 'require-final-newline) nil) ; binary data, dude... 574 (set (make-local-variable 'revert-buffer-function) 'tar-mode-revert) 575 (set (make-local-variable 'local-enable-local-variables) nil) 576 (set (make-local-variable 'next-line-add-newlines) nil) 577 ;; Prevent loss of data when saving the file. 578 (set (make-local-variable 'file-precious-flag) t) 579 (auto-save-mode 0) 580 (set (make-local-variable 'write-contents-functions) '(tar-mode-write-file)) 581 (buffer-disable-undo) 582 (widen) 583 (if (and (boundp 'tar-header-offset) tar-header-offset) 584 (narrow-to-region (point-min) (byte-to-position tar-header-offset)) 585 (tar-summarize-buffer) 586 (tar-next-line 0))) 587 588 589(defun tar-subfile-mode (p) 590 "Minor mode for editing an element of a tar-file. 591This mode arranges for \"saving\" this buffer to write the data 592into the tar-file buffer that it came from. The changes will actually 593appear on disk when you save the tar-file's buffer." 594 (interactive "P") 595 (or (and (boundp 'tar-superior-buffer) tar-superior-buffer) 596 (error "This buffer is not an element of a tar file")) 597 ;; Don't do this, because it is redundant and wastes mode line space. 598 ;; (or (assq 'tar-subfile-mode minor-mode-alist) 599 ;; (setq minor-mode-alist (append minor-mode-alist 600 ;; (list '(tar-subfile-mode " TarFile"))))) 601 (make-local-variable 'tar-subfile-mode) 602 (setq tar-subfile-mode 603 (if (null p) 604 (not tar-subfile-mode) 605 (> (prefix-numeric-value p) 0))) 606 (cond (tar-subfile-mode 607 (add-hook 'write-file-functions 'tar-subfile-save-buffer nil t) 608 ;; turn off auto-save. 609 (auto-save-mode -1) 610 (setq buffer-auto-save-file-name nil) 611 (run-hooks 'tar-subfile-mode-hook)) 612 (t 613 (remove-hook 'write-file-functions 'tar-subfile-save-buffer t)))) 614 615 616;; Revert the buffer and recompute the dired-like listing. 617(defun tar-mode-revert (&optional no-auto-save no-confirm) 618 (let ((revert-buffer-function nil) 619 (old-offset tar-header-offset) 620 success) 621 (setq tar-header-offset nil) 622 (unwind-protect 623 (and (revert-buffer t no-confirm) 624 (progn (widen) 625 (setq success t) 626 (tar-mode))) 627 ;; If the revert was canceled, 628 ;; put back the old value of tar-header-offset. 629 (or success 630 (setq tar-header-offset old-offset))))) 631 632 633(defun tar-next-line (arg) 634 "Move cursor vertically down ARG lines and to the start of the filename." 635 (interactive "p") 636 (forward-line arg) 637 (if (eobp) nil (forward-char (if tar-mode-show-date 54 36)))) 638 639(defun tar-previous-line (arg) 640 "Move cursor vertically up ARG lines and to the start of the filename." 641 (interactive "p") 642 (tar-next-line (- arg))) 643 644(defun tar-current-descriptor (&optional noerror) 645 "Return the tar-descriptor of the current line, or signals an error." 646 ;; I wish lines had plists, like in ZMACS... 647 (or (nth (count-lines (point-min) 648 (save-excursion (beginning-of-line) (point))) 649 tar-parse-info) 650 (if noerror 651 nil 652 (error "This line does not describe a tar-file entry")))) 653 654(defun tar-get-descriptor () 655 (let* ((descriptor (tar-current-descriptor)) 656 (tokens (tar-desc-tokens descriptor)) 657 (size (tar-header-size tokens)) 658 (link-p (tar-header-link-type tokens))) 659 (if link-p 660 (error "This is a %s, not a real file" 661 (cond ((eq link-p 5) "directory") 662 ((eq link-p 20) "tar directory header") 663 ((eq link-p 28) "next has longname") 664 ((eq link-p 29) "multivolume-continuation") 665 ((eq link-p 35) "sparse entry") 666 ((eq link-p 38) "volume header") 667 (t "link")))) 668 (if (zerop size) (error "This is a zero-length file")) 669 descriptor)) 670 671(defun tar-mouse-extract (event) 672 "Extract a file whose tar directory line you click on." 673 (interactive "e") 674 (save-excursion 675 (set-buffer (window-buffer (posn-window (event-end event)))) 676 (save-excursion 677 (goto-char (posn-point (event-end event))) 678 ;; Just make sure this doesn't get an error. 679 (tar-get-descriptor))) 680 (select-window (posn-window (event-end event))) 681 (goto-char (posn-point (event-end event))) 682 (tar-extract)) 683 684(defun tar-file-name-handler (op &rest args) 685 "Helper function for `tar-extract'." 686 (or (eq op 'file-exists-p) 687 (let ((file-name-handler-alist nil)) 688 (apply op args)))) 689 690(defun tar-extract (&optional other-window-p) 691 "In Tar mode, extract this entry of the tar file into its own buffer." 692 (interactive) 693 (let* ((view-p (eq other-window-p 'view)) 694 (descriptor (tar-get-descriptor)) 695 (tokens (tar-desc-tokens descriptor)) 696 (name (tar-header-name tokens)) 697 (size (tar-header-size tokens)) 698 (start (+ (tar-desc-data-start descriptor) 699 (- tar-header-offset (point-min)))) 700 (end (+ start size))) 701 (let* ((tar-buffer (current-buffer)) 702 (tar-buffer-multibyte enable-multibyte-characters) 703 (tarname (buffer-name)) 704 (bufname (concat (file-name-nondirectory name) 705 " (" 706 tarname 707 ")")) 708 (read-only-p (or buffer-read-only view-p)) 709 (new-buffer-file-name (expand-file-name 710 ;; `:' is not allowed on Windows 711 (concat tarname "!" name))) 712 (buffer (get-file-buffer new-buffer-file-name)) 713 (just-created nil)) 714 (unless buffer 715 (setq buffer (generate-new-buffer bufname)) 716 (setq bufname (buffer-name buffer)) 717 (setq just-created t) 718 (unwind-protect 719 (progn 720 (widen) 721 (set-buffer-multibyte nil) 722 (save-excursion 723 (set-buffer buffer) 724 (let ((buffer-undo-list t)) 725 (if enable-multibyte-characters 726 (progn 727 ;; We must avoid unibyte->multibyte conversion. 728 (set-buffer-multibyte nil) 729 (insert-buffer-substring tar-buffer start end) 730 (set-buffer-multibyte t)) 731 (insert-buffer-substring tar-buffer start end)) 732 (goto-char (point-min)) 733 (setq buffer-file-name new-buffer-file-name) 734 (setq buffer-file-truename 735 (abbreviate-file-name buffer-file-name)) 736 ;; We need to mimic the parts of insert-file-contents 737 ;; which determine the coding-system and decode the text. 738 (let ((coding 739 (or coding-system-for-read 740 (and set-auto-coding-function 741 (save-excursion 742 (funcall set-auto-coding-function 743 name (- (point-max) (point))))) 744 ;; The following binding causes 745 ;; find-buffer-file-type-coding-system 746 ;; (defined on dos-w32.el) to act as if 747 ;; the file being extracted existed, so 748 ;; that the file's contents' encoding and 749 ;; EOL format are auto-detected. 750 (let ((file-name-handler-alist 751 (if (featurep 'dos-w32) 752 '(("" . tar-file-name-handler)) 753 file-name-handler-alist))) 754 (car (find-operation-coding-system 755 'insert-file-contents 756 (cons name (current-buffer)) t))))) 757 (multibyte enable-multibyte-characters) 758 (detected (detect-coding-region 759 (point-min) 760 (min (+ (point-min) 16384) (point-max)) t))) 761 (if coding 762 (or (numberp (coding-system-eol-type coding)) 763 (vectorp (coding-system-eol-type detected)) 764 (setq coding (coding-system-change-eol-conversion 765 coding 766 (coding-system-eol-type detected)))) 767 (setq coding 768 (find-new-buffer-file-coding-system detected))) 769 (if (or (eq coding 'no-conversion) 770 (eq (coding-system-type coding) 5)) 771 (setq multibyte (set-buffer-multibyte nil))) 772 (or multibyte 773 (setq coding 774 (coding-system-change-text-conversion 775 coding 'raw-text))) 776 (decode-coding-region (point-min) (point-max) coding) 777 ;; Force buffer-file-coding-system to what 778 ;; decode-coding-region actually used. 779 (set-buffer-file-coding-system last-coding-system-used t)) 780 ;; Set the default-directory to the dir of the 781 ;; superior buffer. 782 (setq default-directory 783 (save-excursion 784 (set-buffer tar-buffer) 785 default-directory)) 786 (normal-mode) ; pick a mode. 787 (rename-buffer bufname) 788 (make-local-variable 'tar-superior-buffer) 789 (make-local-variable 'tar-superior-descriptor) 790 (setq tar-superior-buffer tar-buffer) 791 (setq tar-superior-descriptor descriptor) 792 (setq buffer-read-only read-only-p) 793 (set-buffer-modified-p nil)) 794 (tar-subfile-mode 1)) 795 (set-buffer tar-buffer)) 796 (narrow-to-region (point-min) tar-header-offset) 797 (set-buffer-multibyte tar-buffer-multibyte))) 798 (if view-p 799 (view-buffer buffer (and just-created 'kill-buffer)) 800 (if (eq other-window-p 'display) 801 (display-buffer buffer) 802 (if other-window-p 803 (switch-to-buffer-other-window buffer) 804 (switch-to-buffer buffer))))))) 805 806 807(defun tar-extract-other-window () 808 "In Tar mode, find this entry of the tar file in another window." 809 (interactive) 810 (tar-extract t)) 811 812(defun tar-display-other-window () 813 "In Tar mode, display this entry of the tar file in another window." 814 (interactive) 815 (tar-extract 'display)) 816 817(defun tar-view () 818 "In Tar mode, view the tar file entry on this line." 819 (interactive) 820 (tar-extract 'view)) 821 822 823(defun tar-read-file-name (&optional prompt) 824 "Read a file name with this line's entry as the default." 825 (or prompt (setq prompt "Copy to: ")) 826 (let* ((default-file (expand-file-name 827 (tar-header-name (tar-desc-tokens 828 (tar-current-descriptor))))) 829 (target (expand-file-name 830 (read-file-name prompt 831 (file-name-directory default-file) 832 default-file nil)))) 833 (if (or (string= "" (file-name-nondirectory target)) 834 (file-directory-p target)) 835 (setq target (concat (if (string-match "/$" target) 836 (substring target 0 (1- (match-end 0))) 837 target) 838 "/" 839 (file-name-nondirectory default-file)))) 840 target)) 841 842 843(defun tar-copy (&optional to-file) 844 "In Tar mode, extract this entry of the tar file into a file on disk. 845If TO-FILE is not supplied, it is prompted for, defaulting to the name of 846the current tar-entry." 847 (interactive (list (tar-read-file-name))) 848 (let* ((descriptor (tar-get-descriptor)) 849 (tokens (tar-desc-tokens descriptor)) 850 (name (tar-header-name tokens)) 851 (size (tar-header-size tokens)) 852 (start (+ (tar-desc-data-start descriptor) 853 (- tar-header-offset (point-min)))) 854 (end (+ start size)) 855 (multibyte enable-multibyte-characters) 856 (inhibit-file-name-handlers inhibit-file-name-handlers) 857 (inhibit-file-name-operation inhibit-file-name-operation)) 858 (save-restriction 859 (widen) 860 ;; Inhibit compressing a subfile again if *both* name and 861 ;; to-file are handled by jka-compr 862 (if (and (eq (find-file-name-handler name 'write-region) 'jka-compr-handler) 863 (eq (find-file-name-handler to-file 'write-region) 'jka-compr-handler)) 864 (setq inhibit-file-name-handlers 865 (cons 'jka-compr-handler 866 (and (eq inhibit-file-name-operation 'write-region) 867 inhibit-file-name-handlers)) 868 inhibit-file-name-operation 'write-region)) 869 (unwind-protect 870 (let ((coding-system-for-write 'no-conversion)) 871 (set-buffer-multibyte nil) 872 (write-region start end to-file nil nil nil t)) 873 (set-buffer-multibyte multibyte))) 874 (message "Copied tar entry %s to %s" name to-file))) 875 876(defun tar-flag-deleted (p &optional unflag) 877 "In Tar mode, mark this sub-file to be deleted from the tar file. 878With a prefix argument, mark that many files." 879 (interactive "p") 880 (beginning-of-line) 881 (dotimes (i (abs p)) 882 (if (tar-current-descriptor unflag) ; barf if we're not on an entry-line. 883 (progn 884 (delete-char 1) 885 (insert (if unflag " " "D")))) 886 (forward-line (if (< p 0) -1 1))) 887 (if (eobp) nil (forward-char 36))) 888 889(defun tar-unflag (p) 890 "In Tar mode, un-mark this sub-file if it is marked to be deleted. 891With a prefix argument, un-mark that many files forward." 892 (interactive "p") 893 (tar-flag-deleted p t)) 894 895(defun tar-unflag-backwards (p) 896 "In Tar mode, un-mark this sub-file if it is marked to be deleted. 897With a prefix argument, un-mark that many files backward." 898 (interactive "p") 899 (tar-flag-deleted (- p) t)) 900 901 902;; When this function is called, it is sure that the buffer is unibyte. 903(defun tar-expunge-internal () 904 "Expunge the tar-entry specified by the current line." 905 (let* ((descriptor (tar-current-descriptor)) 906 (tokens (tar-desc-tokens descriptor)) 907 ;; (line (tar-desc-data-start descriptor)) 908 (name (tar-header-name tokens)) 909 (size (tar-header-size tokens)) 910 (link-p (tar-header-link-type tokens)) 911 (start (tar-desc-data-start descriptor)) 912 (following-descs (cdr (memq descriptor tar-parse-info)))) 913 (if link-p (setq size 0)) ; size lies for hard-links. 914 ;; 915 ;; delete the current line... 916 (beginning-of-line) 917 (let ((line-start (point))) 918 (end-of-line) (forward-char) 919 ;; decrement the header-pointer to be in sync... 920 (setq tar-header-offset (- tar-header-offset (- (point) line-start))) 921 (delete-region line-start (point))) 922 ;; 923 ;; delete the data pointer... 924 (setq tar-parse-info (delq descriptor tar-parse-info)) 925 ;; 926 ;; delete the data from inside the file... 927 (widen) 928 (let* ((data-start (+ start (- tar-header-offset (point-min)) -512)) 929 (data-end (+ data-start 512 (ash (ash (+ size 511) -9) 9)))) 930 (delete-region data-start data-end) 931 ;; 932 ;; and finally, decrement the start-pointers of all following 933 ;; entries in the archive. This is a pig when deleting a bunch 934 ;; of files at once - we could optimize this to only do the 935 ;; iteration over the files that remain, or only iterate up to 936 ;; the next file to be deleted. 937 (let ((data-length (- data-end data-start))) 938 (dolist (desc following-descs) 939 (tar-setf (tar-desc-data-start desc) 940 (- (tar-desc-data-start desc) data-length)))) 941 )) 942 (narrow-to-region (point-min) tar-header-offset)) 943 944 945(defun tar-expunge (&optional noconfirm) 946 "In Tar mode, delete all the archived files flagged for deletion. 947This does not modify the disk image; you must save the tar file itself 948for this to be permanent." 949 (interactive) 950 (if (or noconfirm 951 (y-or-n-p "Expunge files marked for deletion? ")) 952 (let ((n 0) 953 (multibyte enable-multibyte-characters)) 954 (save-excursion 955 (widen) 956 (set-buffer-multibyte nil) 957 (goto-char (point-min)) 958 (while (not (eobp)) 959 (if (looking-at "D") 960 (progn (tar-expunge-internal) 961 (setq n (1+ n))) 962 (forward-line 1))) 963 ;; after doing the deletions, add any padding that may be necessary. 964 (tar-pad-to-blocksize) 965 (widen) 966 (set-buffer-multibyte multibyte) 967 (narrow-to-region (point-min) tar-header-offset)) 968 (if (zerop n) 969 (message "Nothing to expunge.") 970 (message "%s files expunged. Be sure to save this buffer." n))))) 971 972 973(defun tar-clear-modification-flags () 974 "Remove the stars at the beginning of each line." 975 (interactive) 976 (save-excursion 977 (goto-char (point-min)) 978 (while (< (position-bytes (point)) tar-header-offset) 979 (if (not (eq (following-char) ?\s)) 980 (progn (delete-char 1) (insert " "))) 981 (forward-line 1)))) 982 983 984(defun tar-chown-entry (new-uid) 985 "Change the user-id associated with this entry in the tar file. 986If this tar file was written by GNU tar, then you will be able to edit 987the user id as a string; otherwise, you must edit it as a number. 988You can force editing as a number by calling this with a prefix arg. 989This does not modify the disk image; you must save the tar file itself 990for this to be permanent." 991 (interactive (list 992 (let ((tokens (tar-desc-tokens (tar-current-descriptor)))) 993 (if (or current-prefix-arg 994 (not (tar-header-magic tokens))) 995 (let (n) 996 (while (not (numberp (setq n (read-minibuffer 997 "New UID number: " 998 (format "%s" (tar-header-uid tokens))))))) 999 n) 1000 (read-string "New UID string: " (tar-header-uname tokens)))))) 1001 (cond ((stringp new-uid) 1002 (tar-setf (tar-header-uname (tar-desc-tokens (tar-current-descriptor))) 1003 new-uid) 1004 (tar-alter-one-field tar-uname-offset (concat new-uid "\000"))) 1005 (t 1006 (tar-setf (tar-header-uid (tar-desc-tokens (tar-current-descriptor))) 1007 new-uid) 1008 (tar-alter-one-field tar-uid-offset 1009 (concat (substring (format "%6o" new-uid) 0 6) "\000 "))))) 1010 1011 1012(defun tar-chgrp-entry (new-gid) 1013 "Change the group-id associated with this entry in the tar file. 1014If this tar file was written by GNU tar, then you will be able to edit 1015the group id as a string; otherwise, you must edit it as a number. 1016You can force editing as a number by calling this with a prefix arg. 1017This does not modify the disk image; you must save the tar file itself 1018for this to be permanent." 1019 (interactive (list 1020 (let ((tokens (tar-desc-tokens (tar-current-descriptor)))) 1021 (if (or current-prefix-arg 1022 (not (tar-header-magic tokens))) 1023 (let (n) 1024 (while (not (numberp (setq n (read-minibuffer 1025 "New GID number: " 1026 (format "%s" (tar-header-gid tokens))))))) 1027 n) 1028 (read-string "New GID string: " (tar-header-gname tokens)))))) 1029 (cond ((stringp new-gid) 1030 (tar-setf (tar-header-gname (tar-desc-tokens (tar-current-descriptor))) 1031 new-gid) 1032 (tar-alter-one-field tar-gname-offset 1033 (concat new-gid "\000"))) 1034 (t 1035 (tar-setf (tar-header-gid (tar-desc-tokens (tar-current-descriptor))) 1036 new-gid) 1037 (tar-alter-one-field tar-gid-offset 1038 (concat (substring (format "%6o" new-gid) 0 6) "\000 "))))) 1039 1040(defun tar-rename-entry (new-name) 1041 "Change the name associated with this entry in the tar file. 1042This does not modify the disk image; you must save the tar file itself 1043for this to be permanent." 1044 (interactive 1045 (list (read-string "New name: " 1046 (tar-header-name (tar-desc-tokens (tar-current-descriptor)))))) 1047 (if (string= "" new-name) (error "zero length name")) 1048 (if (> (length new-name) 98) (error "name too long")) 1049 (tar-setf (tar-header-name (tar-desc-tokens (tar-current-descriptor))) 1050 new-name) 1051 (if (multibyte-string-p new-name) 1052 (setq new-name (encode-coding-string new-name 1053 (or file-name-coding-system 1054 default-file-name-coding-system)))) 1055 (tar-alter-one-field 0 1056 (substring (concat new-name (make-string 99 0)) 0 99))) 1057 1058 1059(defun tar-chmod-entry (new-mode) 1060 "Change the protection bits associated with this entry in the tar file. 1061This does not modify the disk image; you must save the tar file itself 1062for this to be permanent." 1063 (interactive (list (tar-parse-octal-integer-safe 1064 (read-string "New protection (octal): ")))) 1065 (tar-setf (tar-header-mode (tar-desc-tokens (tar-current-descriptor))) 1066 new-mode) 1067 (tar-alter-one-field tar-mode-offset 1068 (concat (substring (format "%6o" new-mode) 0 6) "\000 "))) 1069 1070 1071(defun tar-alter-one-field (data-position new-data-string) 1072 (let* ((descriptor (tar-current-descriptor)) 1073 (tokens (tar-desc-tokens descriptor)) 1074 (multibyte enable-multibyte-characters)) 1075 (unwind-protect 1076 (save-excursion 1077 ;; 1078 ;; update the header-line. 1079 (beginning-of-line) 1080 (let ((p (point))) 1081 (forward-line 1) 1082 (delete-region p (point)) 1083 (insert (tar-header-block-summarize tokens) "\n") 1084 (setq tar-header-offset (position-bytes (point-max)))) 1085 1086 (widen) 1087 (set-buffer-multibyte nil) 1088 (let* ((start (+ (tar-desc-data-start descriptor) 1089 (- tar-header-offset (point-min)) 1090 -512))) 1091 ;; 1092 ;; delete the old field and insert a new one. 1093 (goto-char (+ start data-position)) 1094 (delete-region (point) (+ (point) (length new-data-string))) ; <-- 1095 (insert new-data-string) ; <-- 1096 ;; 1097 ;; compute a new checksum and insert it. 1098 (let ((chk (tar-header-block-checksum 1099 (buffer-substring start (+ start 512))))) 1100 (goto-char (+ start tar-chk-offset)) 1101 (delete-region (point) (+ (point) 8)) 1102 (insert (format "%6o" chk)) 1103 (insert 0) 1104 (insert ? ) 1105 (tar-setf (tar-header-checksum tokens) chk) 1106 ;; 1107 ;; ok, make sure we didn't botch it. 1108 (tar-header-block-check-checksum 1109 (buffer-substring start (+ start 512)) 1110 chk (tar-header-name tokens)) 1111 ))) 1112 (narrow-to-region (point-min) tar-header-offset) 1113 (set-buffer-multibyte multibyte) 1114 (tar-next-line 0)))) 1115 1116 1117(defun tar-octal-time (timeval) 1118 ;; Format a timestamp as 11 octal digits. Ghod, I hope this works... 1119 (let ((hibits (car timeval)) (lobits (car (cdr timeval)))) 1120 (format "%05o%01o%05o" 1121 (lsh hibits -2) 1122 (logior (lsh (logand 3 hibits) 1) 1123 (if (> (logand lobits 32768) 0) 1 0)) 1124 (logand 32767 lobits) 1125 ))) 1126 1127(defun tar-subfile-save-buffer () 1128 "In tar subfile mode, save this buffer into its parent tar-file buffer. 1129This doesn't write anything to disk; you must save the parent tar-file buffer 1130to make your changes permanent." 1131 (interactive) 1132 (if (not (and (boundp 'tar-superior-buffer) tar-superior-buffer)) 1133 (error "This buffer has no superior tar file buffer")) 1134 (if (not (and (boundp 'tar-superior-descriptor) tar-superior-descriptor)) 1135 (error "This buffer doesn't have an index into its superior tar file!")) 1136 (save-excursion 1137 (let ((subfile (current-buffer)) 1138 (subfile-multibyte enable-multibyte-characters) 1139 (coding buffer-file-coding-system) 1140 (descriptor tar-superior-descriptor) 1141 subfile-size) 1142 ;; We must make the current buffer unibyte temporarily to avoid 1143 ;; multibyte->unibyte conversion in `insert-buffer-substring'. 1144 (set-buffer-multibyte nil) 1145 (setq subfile-size (buffer-size)) 1146 (set-buffer tar-superior-buffer) 1147 (let* ((tokens (tar-desc-tokens descriptor)) 1148 (start (tar-desc-data-start descriptor)) 1149 (name (tar-header-name tokens)) 1150 (size (tar-header-size tokens)) 1151 (size-pad (ash (ash (+ size 511) -9) 9)) 1152 (head (memq descriptor tar-parse-info)) 1153 (following-descs (cdr head)) 1154 (tar-buffer-multibyte enable-multibyte-characters)) 1155 (if (not head) 1156 (error "Can't find this tar file entry in its parent tar file!")) 1157 (unwind-protect 1158 (save-excursion 1159 (widen) 1160 (set-buffer-multibyte nil) 1161 ;; delete the old data... 1162 (let* ((data-start (+ start (- tar-header-offset (point-min)))) 1163 (data-end (+ data-start (ash (ash (+ size 511) -9) 9)))) 1164 (delete-region data-start data-end) 1165 ;; insert the new data... 1166 (goto-char data-start) 1167 (insert-buffer-substring subfile) 1168 (setq subfile-size 1169 (encode-coding-region 1170 data-start (+ data-start subfile-size) coding)) 1171 ;; 1172 ;; pad the new data out to a multiple of 512... 1173 (let ((subfile-size-pad (ash (ash (+ subfile-size 511) -9) 9))) 1174 (goto-char (+ data-start subfile-size)) 1175 (insert (make-string (- subfile-size-pad subfile-size) 0)) 1176 ;; 1177 ;; update the data pointer of this and all following files... 1178 (tar-setf (tar-header-size tokens) subfile-size) 1179 (let ((difference (- subfile-size-pad size-pad))) 1180 (dolist (desc following-descs) 1181 (tar-setf (tar-desc-data-start desc) 1182 (+ (tar-desc-data-start desc) difference)))) 1183 ;; 1184 ;; Update the size field in the header block. 1185 (let ((header-start (- data-start 512))) 1186 (goto-char (+ header-start tar-size-offset)) 1187 (delete-region (point) (+ (point) 12)) 1188 (insert (format "%11o" subfile-size)) 1189 (insert ? ) 1190 ;; 1191 ;; Maybe update the datestamp. 1192 (if (not tar-update-datestamp) 1193 nil 1194 (goto-char (+ header-start tar-time-offset)) 1195 (delete-region (point) (+ (point) 12)) 1196 (insert (tar-octal-time (current-time))) 1197 (insert ? )) 1198 ;; 1199 ;; compute a new checksum and insert it. 1200 (let ((chk (tar-header-block-checksum 1201 (buffer-substring header-start data-start)))) 1202 (goto-char (+ header-start tar-chk-offset)) 1203 (delete-region (point) (+ (point) 8)) 1204 (insert (format "%6o" chk)) 1205 (insert 0) 1206 (insert ? ) 1207 (tar-setf (tar-header-checksum tokens) chk))) 1208 ;; 1209 ;; alter the descriptor-line... 1210 ;; 1211 (let ((position (- (length tar-parse-info) (length head)))) 1212 (goto-char (point-min)) 1213 (next-line position) 1214 (beginning-of-line) 1215 (let ((p (point)) 1216 after 1217 (m (set-marker (make-marker) tar-header-offset))) 1218 (forward-line 1) 1219 (setq after (point)) 1220 ;; Insert the new text after the old, before deleting, 1221 ;; to preserve the window start. 1222 (let ((line (tar-header-block-summarize tokens t))) 1223 (insert-before-markers (string-as-unibyte line) "\n")) 1224 (delete-region p after) 1225 (setq tar-header-offset (marker-position m))) 1226 ))) 1227 ;; after doing the insertion, add any final padding that may be necessary. 1228 (tar-pad-to-blocksize)) 1229 (narrow-to-region (point-min) tar-header-offset) 1230 (set-buffer-multibyte tar-buffer-multibyte))) 1231 (set-buffer-modified-p t) ; mark the tar file as modified 1232 (tar-next-line 0) 1233 (set-buffer subfile) 1234 ;; Restore the buffer multibyteness. 1235 (set-buffer-multibyte subfile-multibyte) 1236 (set-buffer-modified-p nil) ; mark the tar subfile as unmodified 1237 (message "Saved into tar-buffer `%s'. Be sure to save that buffer!" 1238 (buffer-name tar-superior-buffer)) 1239 ;; Prevent basic-save-buffer from changing our coding-system. 1240 (setq last-coding-system-used buffer-file-coding-system) 1241 ;; Prevent ordinary saving from happening. 1242 t))) 1243 1244 1245;; When this function is called, it is sure that the buffer is unibyte. 1246(defun tar-pad-to-blocksize () 1247 "If we are being anal about tar file blocksizes, fix up the current buffer. 1248Leaves the region wide." 1249 (if (null tar-anal-blocksize) 1250 nil 1251 (widen) 1252 (let* ((last-desc (nth (1- (length tar-parse-info)) tar-parse-info)) 1253 (start (tar-desc-data-start last-desc)) 1254 (tokens (tar-desc-tokens last-desc)) 1255 (link-p (tar-header-link-type tokens)) 1256 (size (if link-p 0 (tar-header-size tokens))) 1257 (data-end (+ start size)) 1258 (bbytes (ash tar-anal-blocksize 9)) 1259 (pad-to (+ bbytes (* bbytes (/ (- data-end (point-min)) bbytes)))) 1260 (inhibit-read-only t) ; ## 1261 ) 1262 ;; If the padding after the last data is too long, delete some; 1263 ;; else insert some until we are padded out to the right number of blocks. 1264 ;; 1265 (let ((goal-end (+ (or tar-header-offset 0) pad-to))) 1266 (if (> (point-max) goal-end) 1267 (delete-region goal-end (point-max)) 1268 (goto-char (point-max)) 1269 (insert (make-string (- goal-end (point-max)) ?\0))))))) 1270 1271 1272;; Used in write-file-hook to write tar-files out correctly. 1273(defun tar-mode-write-file () 1274 (unwind-protect 1275 (save-excursion 1276 (widen) 1277 ;; Doing this here confuses things - the region gets left too wide! 1278 ;; I suppose this is run in a context where changing the buffer is bad. 1279 ;; (tar-pad-to-blocksize) 1280 ;; tar-header-offset turns out to be null for files fetched with W3, 1281 ;; at least. 1282 (let ((coding-system-for-write 'no-conversion)) 1283 (write-region (if tar-header-offset 1284 (byte-to-position tar-header-offset) 1285 (point-min)) 1286 (point-max) 1287 buffer-file-name nil t)) 1288 (tar-clear-modification-flags) 1289 (set-buffer-modified-p nil)) 1290 (narrow-to-region (point-min) (byte-to-position tar-header-offset))) 1291 ;; Return t because we've written the file. 1292 t) 1293 1294(provide 'tar-mode) 1295 1296;; arch-tag: 8a585a4a-340e-42c2-89e7-d3b1013a4b78 1297;;; tar-mode.el ends here 1298