;;; tar-mode.el --- simple editing of tar files from GNU emacs
;; Copyright (C) 1990, 1991, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
-;; 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008 Free Software Foundation, Inc.
+;; 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
;; Author: Jamie Zawinski <jwz@lucid.com>
;; Maintainer: FSF
;;; Bugs:
-;; - Expunge and rename on ././@LongLink files
+;; - Rename on ././@LongLink files
;; - Revert confirmation displays the raw data temporarily.
-;; - Incorrect goal-column if username is too long.
;;; Code:
(defvar tar-data-buffer nil "Buffer that holds the actual raw tar bytes.")
(make-variable-buffer-local 'tar-data-buffer)
+(defvar tar-data-swapped nil
+ "If non-nil, `tar-data-buffer' indeed holds raw tar bytes.")
+(make-variable-buffer-local 'tar-data-swapped)
+
(defun tar-data-swapped-p ()
"Return non-nil if the tar-data is in `tar-data-buffer'."
- ;; We need to be careful to keep track of which buffer holds the tar-data,
- ;; since we swap them back and forth. Since the user may make the summary
- ;; buffer unibyte, we can't rely on the multibyteness of the buffers.
- ;; We could try and recognize the tar-format signature, but instead
- ;; I decided to go for something simpler.
(and (buffer-live-p tar-data-buffer)
- (> (buffer-size tar-data-buffer) (buffer-size))))
-
+ ;; Sanity check to try and make sure tar-data-swapped tracks the swap
+ ;; state correctly: the raw data is expected to be always larger than
+ ;; the summary.
+ (progn
+ (assert (eq tar-data-swapped
+ (> (buffer-size tar-data-buffer) (buffer-size))))
+ tar-data-swapped)))
+
+(defun tar-swap-data ()
+ "Swap buffer contents between current buffer and `tar-data-buffer'.
+Preserve the modified states of the buffers and set `buffer-swapped-with'."
+ (let ((data-buffer-modified-p (buffer-modified-p tar-data-buffer))
+ (current-buffer-modified-p (buffer-modified-p)))
+ (buffer-swap-text tar-data-buffer)
+ (setq tar-data-swapped (not tar-data-swapped))
+ (restore-buffer-modified-p data-buffer-modified-p)
+ (with-current-buffer tar-data-buffer
+ (restore-buffer-modified-p current-buffer-modified-p))))
\f
;;; down to business.
make-tar-header (data-start name mode uid gid size date checksum
link-type link-name magic uname gname dmaj dmin)))
data-start name mode uid gid size date checksum link-type link-name
- magic uname gname dmaj dmin)
+ magic uname gname dmaj dmin
+ ;; Start of the header can be nil (meaning it's 512 bytes before data-start)
+ ;; or a marker (in case the header uses LongLink thingies).
+ header-start)
(defconst tar-name-offset 0)
(defconst tar-mode-offset (+ tar-name-offset 100))
"Round S up to the next multiple of 512."
(ash (ash (+ s 511) -9) 9))
-(defun tar-header-block-tokenize (pos)
+(defun tar-header-block-tokenize (pos coding)
"Return a `tar-header' structure.
This is a list of name, mode, uid, gid, size,
write-date, checksum, link-type, and link-name."
(gname-end (1- tar-dmaj-offset))
(link-p (aref string tar-linkp-offset))
(magic-str (substring string tar-magic-offset
- (1- tar-uname-offset)))
- (uname-valid-p (member magic-str
- '("ustar " "GNUtar " "ustar\0\0")))
+ ;; The magic string is actually 6bytes
+ ;; of magic string plus 2bytes of version
+ ;; which we here ignore.
+ (- tar-uname-offset 2)))
+ ;; The magic string is "ustar\0" for POSIX format, and
+ ;; "ustar " for GNU Tar's format.
+ (uname-valid-p (car (member magic-str '("ustar " "ustar\0"))))
name linkname
(nulsexp "[^\000]*\000"))
(when (string-match nulsexp string tar-name-offset)
nil
(- link-p ?0)))
(setq linkname (substring string tar-link-offset link-end))
- (when (and uname-valid-p
+ (when (and (equal uname-valid-p "ustar\0")
(string-match nulsexp string tar-prefix-offset)
(> (match-end 0) (1+ tar-prefix-offset)))
(setq name (concat (substring string tar-prefix-offset
"/" name)))
(if default-enable-multibyte-characters
(setq name
- (decode-coding-string name tar-file-name-coding-system)
+ (decode-coding-string name coding)
linkname
- (decode-coding-string linkname
- tar-file-name-coding-system)))
+ (decode-coding-string linkname coding)))
(if (and (null link-p) (string-match "/\\'" name))
(setq link-p 5)) ; directory
(if (and (equal name "././@LongLink")
- (equal magic-str "ustar ")) ;OLDGNU_MAGIC.
+ (equal magic-str "ustar ")) ;OLDGNU_MAGIC.
;; This is a GNU Tar long-file-name header.
(let* ((size (tar-parse-octal-integer
string tar-size-offset tar-time-offset))
;; -1 so as to strip the terminating 0 byte.
(name (buffer-substring pos (+ pos size -1)))
(descriptor (tar-header-block-tokenize
- (+ pos (tar-roundup-512 size)))))
+ (+ pos (tar-roundup-512 size))
+ coding)))
(cond
((eq link-p (- ?L ?0)) ;GNUTYPE_LONGNAME.
(setf (tar-header-name descriptor) name))
(setf (tar-header-link-name descriptor) name))
(t
(message "Unrecognized GNU Tar @LongLink format")))
+ (setf (tar-header-header-start descriptor)
+ (copy-marker (- pos 512) t))
descriptor)
(make-tar-header
(tar-parse-octal-integer string tar-dmin-offset tar-prefix-offset)
))))))
+;; Pseudo-field.
+(defun tar-header-data-end (descriptor)
+ (let* ((data-start (tar-header-data-start descriptor))
+ (link-type (tar-header-link-type descriptor))
+ (size (tar-header-size descriptor))
+ (fudge (cond
+ ;; Foo. There's an extra empty block after these.
+ ((memq link-type '(20 55)) 512)
+ (t 0))))
+ (+ data-start fudge
+ (if (and (null link-type) (> size 0))
+ (tar-roundup-512 size)
+ 0))))
(defun tar-parse-octal-integer (string &optional start end)
(if (null start) (setq start 0))
(defun tar-header-block-checksum (string)
"Compute and return a tar-acceptable checksum for this block."
(assert (not (multibyte-string-p string)))
- (setq string (string-as-unibyte string))
(let* ((chk-field-start tar-chk-offset)
(chk-field-end (+ chk-field-start 8))
(sum 0)
;; (ck (tar-header-checksum tar-hblock))
(type (tar-header-link-type tar-hblock))
(link-name (tar-header-link-name tar-hblock)))
- (format "%c%c%s%8s/%-8s%7s%s %s%s"
+ (format "%c%c%s %7s/%-7s %7s%s %s%s"
(if mod-p ?* ? )
(cond ((or (eq type nil) (eq type 0)) ?-)
((eq type 1) ?h) ; link
(let* ((modified (buffer-modified-p))
(result '())
(pos (point-min))
+ (coding tar-file-name-coding-system)
(progress-reporter
(with-current-buffer tar-data-buffer
(make-progress-reporter "Parsing tar file..."
descriptor)
(with-current-buffer tar-data-buffer
(while (and (<= (+ pos 512) (point-max))
- (setq descriptor (tar-header-block-tokenize pos)))
- (setq pos (marker-position (tar-header-data-start descriptor)))
- (progress-reporter-update progress-reporter pos)
- (if (memq (tar-header-link-type descriptor) '(20 55))
- ;; Foo. There's an extra empty block after these.
- (setq pos (+ pos 512)))
+ (setq descriptor (tar-header-block-tokenize pos coding)))
(let ((size (tar-header-size descriptor)))
(if (< size 0)
(error "%s has size %s - corrupted"
- (tar-header-name descriptor) size))
- ;;
- ;; This is just too slow. Don't really need it anyway....
- ;;(tar-header-block-check-checksum
- ;; hblock (tar-header-block-checksum hblock)
- ;; (tar-header-name descriptor))
-
- (push descriptor result)
-
- (and (null (tar-header-link-type descriptor))
- (> size 0)
- (setq pos (+ pos (tar-roundup-512 size)))))))
-
+ (tar-header-name descriptor) size)))
+ ;;
+ ;; This is just too slow. Don't really need it anyway....
+ ;;(tar-header-block-check-checksum
+ ;; hblock (tar-header-block-checksum hblock)
+ ;; (tar-header-name descriptor))
+
+ (push descriptor result)
+ (setq pos (tar-header-data-end descriptor))
+ (progress-reporter-update progress-reporter pos)))
+
(set (make-local-variable 'tar-parse-info) (nreverse result))
;; A tar file should end with a block or two of nulls,
;; but let's not get a fatal error if it doesn't.
(defun tar-change-major-mode-hook ()
;; Bring the actual Tar data back into the main buffer.
- (when (tar-data-swapped-p) (buffer-swap-text tar-data-buffer))
+ (when (tar-data-swapped-p) (tar-swap-data))
;; Throw away the summary.
(when (buffer-live-p tar-data-buffer) (kill-buffer tar-data-buffer)))
;; buffer for the summary.
(assert (not (tar-data-swapped-p)))
(set (make-local-variable 'revert-buffer-function) 'tar-mode-revert)
+ ;; We started using write-contents-functions, but this hook is not
+ ;; used during auto-save, so we now use
+ ;; write-region-annotate-functions which hooks at a lower-level.
(add-hook 'write-region-annotate-functions 'tar-write-region-annotate nil t)
(add-hook 'kill-buffer-hook 'tar-mode-kill-buffer-hook nil t)
(add-hook 'change-major-mode-hook 'tar-change-major-mode-hook nil t)
;; Tar data is made of bytes, not chars.
- (set-buffer-multibyte nil)
+ (set-buffer-multibyte nil) ;Hopefully a no-op.
(set (make-local-variable 'tar-data-buffer)
(generate-new-buffer (format " *tar-data %s*"
(file-name-nondirectory
(or buffer-file-name (buffer-name))))))
- (buffer-swap-text tar-data-buffer)
+ (tar-swap-data)
(tar-summarize-buffer)
(tar-next-line 0))
(defun tar-mode-revert (&optional no-auto-save no-confirm)
(unwind-protect
(let ((revert-buffer-function nil))
- (if (tar-data-swapped-p) (buffer-swap-text tar-data-buffer))
+ (if (tar-data-swapped-p) (tar-swap-data))
;; FIXME: If we ask for confirmation, the user will be temporarily
;; looking at the raw data.
(revert-buffer no-auto-save no-confirm 'preserve-modes)
- ;; The new raw data may be smaller than the old summary, so let's
- ;; make sure tar-data-swapped-p doesn't get confused.
- (if (buffer-live-p tar-data-buffer) (kill-buffer tar-data-buffer))
;; Recompute the summary.
+ (if (buffer-live-p tar-data-buffer) (kill-buffer tar-data-buffer))
(tar-mode))
- (unless (tar-data-swapped-p) (buffer-swap-text tar-data-buffer))))
+ (unless (tar-data-swapped-p) (tar-swap-data))))
(defun tar-next-line (arg)
"Move cursor vertically down ARG lines and to the start of the filename."
(interactive "p")
(forward-line arg)
- (if (eobp) nil (forward-char (if tar-mode-show-date 54 36))))
+ (goto-char (or (next-single-property-change (point) 'mouse-face) (point))))
(defun tar-previous-line (arg)
"Move cursor vertically up ARG lines and to the start of the filename."
(defun tar-expunge-internal ()
"Expunge the tar-entry specified by the current line."
- (let* ((descriptor (tar-current-descriptor))
- ;; (line (tar-header-data-start descriptor))
- (name (tar-header-name descriptor))
- (size (tar-header-size descriptor))
- (link-p (tar-header-link-type descriptor))
- (start (tar-header-data-start descriptor))
- (following-descs (cdr (memq descriptor tar-parse-info))))
- (if link-p (setq size 0)) ; size lies for hard-links.
+ (let ((descriptor (tar-current-descriptor)))
;;
;; delete the current line...
(delete-region (line-beginning-position) (line-beginning-position 2))
(setq tar-parse-info (delq descriptor tar-parse-info))
;;
;; delete the data from inside the file...
- (let* ((data-start (- start 512))
- (data-end (+ start (tar-roundup-512 size))))
- (with-current-buffer tar-data-buffer
- (delete-region data-start data-end)))))
+ (with-current-buffer tar-data-buffer
+ (delete-region (or (tar-header-header-start descriptor)
+ (- (tar-header-data-start descriptor) 512))
+ (tar-header-data-end descriptor)))))
(defun tar-expunge (&optional noconfirm)
(tar-header-name (tar-current-descriptor)))))
(if (string= "" new-name) (error "zero length name"))
(let ((encoded-new-name (encode-coding-string new-name
- tar-file-name-coding-system)))
+ tar-file-name-coding-system))
+ (descriptor (tar-current-descriptor))
+ (prefix nil))
+ (when (tar-header-header-start descriptor)
+ ;; FIXME: Make it work for ././@LongLink.
+ (error "Rename with @LongLink format is not implemented"))
+
+ (when (and (> (length encoded-new-name) 98)
+ (string-match "/" encoded-new-name
+ (- (length encoded-new-name) 99))
+ (< (match-beginning 0) 155))
+ (unless (equal (tar-header-magic descriptor) "ustar\0")
+ (tar-alter-one-field tar-magic-offset (concat "ustar\0" "00")))
+ (setq prefix (substring encoded-new-name 0 (match-beginning 0)))
+ (setq encoded-new-name (substring encoded-new-name (match-end 0))))
+
(if (> (length encoded-new-name) 98) (error "name too long"))
- (setf (tar-header-name (tar-current-descriptor)) new-name)
- ;; FIXME: Make it work for ././@LongLink.
+ (setf (tar-header-name descriptor) new-name)
(tar-alter-one-field 0
- (substring (concat encoded-new-name (make-string 99 0)) 0 99))))
+ (substring (concat encoded-new-name (make-string 99 0)) 0 99))
+ (if prefix
+ (tar-alter-one-field tar-prefix-offset
+ (substring (concat prefix (make-string 155 0)) 0 155)))))
(defun tar-chmod-entry (new-mode)
(concat (substring (format "%6o" new-mode) 0 6) "\000 ")))
-(defun tar-alter-one-field (data-position new-data-string)
- (let* ((descriptor (tar-current-descriptor)))
- ;;
- ;; update the header-line.
- (let ((col (current-column)))
- (delete-region (line-beginning-position) (line-beginning-position 2))
- (insert (tar-header-block-summarize descriptor) "\n")
- (forward-line -1) (move-to-column col))
+(defun tar-alter-one-field (data-position new-data-string &optional descriptor)
+ (unless descriptor (setq descriptor (tar-current-descriptor)))
+ ;;
+ ;; update the header-line.
+ (let ((col (current-column)))
+ (delete-region (line-beginning-position)
+ (prog2 (forward-line 1)
+ (point)
+ ;; Insert the new text after the old, before deleting,
+ ;; to preserve markers such as the window start.
+ (insert (tar-header-block-summarize descriptor) "\n")))
+ (forward-line -1) (move-to-column col))
- (with-current-buffer tar-data-buffer
- (let* ((start (- (tar-header-data-start descriptor) 512)))
+ (assert (tar-data-swapped-p))
+ (with-current-buffer tar-data-buffer
+ (let* ((start (- (tar-header-data-start descriptor) 512)))
;;
;; delete the old field and insert a new one.
(goto-char (+ start data-position))
(delete-region (point) (+ (point) (length new-data-string))) ; <--
-
(assert (not (or enable-multibyte-characters
(multibyte-string-p new-data-string))))
(insert new-data-string)
;;
;; compute a new checksum and insert it.
(let ((chk (tar-header-block-checksum
- (buffer-substring start (+ start 512)))))
- (goto-char (+ start tar-chk-offset))
- (delete-region (point) (+ (point) 8))
- (insert (format "%6o" chk))
- (insert 0)
- (insert ? )
- (setf (tar-header-checksum descriptor) chk)
- ;;
- ;; ok, make sure we didn't botch it.
- (tar-header-block-check-checksum
- (buffer-substring start (+ start 512))
- chk (tar-header-name descriptor))
- )))))
+ (buffer-substring start (+ start 512)))))
+ (goto-char (+ start tar-chk-offset))
+ (delete-region (point) (+ (point) 8))
+ (insert (format "%6o\0 " chk))
+ (setf (tar-header-checksum descriptor) chk)
+ ;;
+ ;; ok, make sure we didn't botch it.
+ (tar-header-block-check-checksum
+ (buffer-substring start (+ start 512))
+ chk (tar-header-name descriptor))
+ ))))
(defun tar-octal-time (timeval)
(setf (tar-header-size descriptor) subfile-size)
;;
;; Update the size field in the header block.
- (widen)
- (let ((header-start (- data-start 512)))
- (goto-char (+ header-start tar-size-offset))
- (delete-region (point) (+ (point) 12))
- (insert (format "%11o " subfile-size))
- ;;
- ;; Maybe update the datestamp.
- (if (not tar-update-datestamp)
- nil
- (goto-char (+ header-start tar-time-offset))
- (delete-region (point) (+ (point) 12))
- (insert (tar-octal-time (current-time)))
- (insert ?\s))
- ;;
- ;; compute a new checksum and insert it.
- (let ((chk (tar-header-block-checksum
- (buffer-substring header-start data-start))))
- (goto-char (+ header-start tar-chk-offset))
- (delete-region (point) (+ (point) 8))
- (insert (format "%6o\0 " chk))
- (setf (tar-header-checksum descriptor) chk))))))
+ (widen))))
;;
- ;; alter the descriptor-line...
+ ;; alter the descriptor-line and header
;;
(let ((position (- (length tar-parse-info) (length head))))
(goto-char (point-min))
(forward-line position)
- (let ((p (point))
- (after (line-beginning-position 2)))
- (goto-char after)
- ;; Insert the new text after the old, before deleting,
- ;; to preserve the window start.
- (let ((line (tar-header-block-summarize descriptor t)))
- (insert-before-markers line "\n"))
- (delete-region p after)))
+ (tar-alter-one-field tar-size-offset (format "%11o " subfile-size))
+ ;;
+ ;; Maybe update the datestamp.
+ (when tar-update-datestamp
+ (tar-alter-one-field tar-time-offset
+ (concat (tar-octal-time (current-time)) " "))))
;; After doing the insertion, add any necessary final padding.
(tar-pad-to-blocksize))
(set-buffer-modified-p t) ; mark the tar file as modified
;; When called from M-x write-region, we assume the user wants to save
;; (part of) the summary, not the tar data.
(unless (or start (not (tar-data-swapped-p)))
- (tar-clear-modification-flags)
+ (tar-clear-modification-flags)
(set-buffer tar-data-buffer)
nil))
-\f
+
(provide 'tar-mode)
;; arch-tag: 8a585a4a-340e-42c2-89e7-d3b1013a4b78