1 ;;; jka-compr.el --- reading/writing/loading compressed files
3 ;; Copyright (C) 1993, 1994 Free Software Foundation, Inc.
5 ;; Author: jka@ece.cmu.edu (Jay K. Adams)
8 ;; This file is part of GNU Emacs.
10 ;; GNU Emacs is free software; you can redistribute it and/or modify
11 ;; it under the terms of the GNU General Public License as published by
12 ;; the Free Software Foundation; either version 2, or (at your option)
15 ;; GNU Emacs is distributed in the hope that it will be useful,
16 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
17 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 ;; GNU General Public License for more details.
20 ;; You should have received a copy of the GNU General Public License
21 ;; along with GNU Emacs; see the file COPYING. If not, write to the
22 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
23 ;; Boston, MA 02111-1307, USA.
27 ;; This package implements low-level support for reading, writing,
28 ;; and loading compressed files. It hooks into the low-level file
29 ;; I/O functions (including write-region and insert-file-contents) so
30 ;; that they automatically compress or uncompress a file if the file
31 ;; appears to need it (based on the extension of the file name).
32 ;; Packages like Rmail, VM, GNUS, and Info should be able to work
33 ;; with compressed files without modification.
38 ;; To use jka-compr, simply load this package, and edit as usual.
39 ;; Its operation should be transparent to the user (except for
40 ;; messages appearing when a file is being compressed or
43 ;; The variable, jka-compr-compression-info-list can be used to
44 ;; customize jka-compr to work with other compression programs.
45 ;; The default value of this variable allows jka-compr to work with
46 ;; Unix compress and gzip.
48 ;; If you are concerned about the stderr output of gzip and other
49 ;; compression/decompression programs showing up in your buffers, you
50 ;; should set the discard-error flag in the compression-info-list.
51 ;; This will cause the stderr of all programs to be discarded.
52 ;; However, it also causes emacs to call compression/uncompression
53 ;; programs through a shell (which is specified by jka-compr-shell).
54 ;; This may be a drag if, on your system, starting up a shell is
57 ;; If you don't want messages about compressing and decompressing
58 ;; to show up in the echo area, you can set the compress-name and
59 ;; decompress-name fields of the jka-compr-compression-info-list to
66 ;; jka-compr can coexist with crpyt++ if you take all the decompression
67 ;; entries out of the crypt-encoding-list. Clearly problems will arise if
68 ;; you have two programs trying to compress/decompress files. jka-compr
69 ;; will not "work with" crypt++ in the following sense: you won't be able to
70 ;; decode encrypted compressed files--that is, files that have been
71 ;; compressed then encrypted (in that order). Theoretically, crypt++ and
72 ;; jka-compr could properly handle a file that has been encrypted then
73 ;; compressed, but there is little point in trying to compress an encrypted
80 ;; jka-compr is a V19 adaptation of jka-compr for V18 of Emacs. Many people
81 ;; have made helpful suggestions, reported bugs, and even fixed bugs in
82 ;; jka-compr. I recall the following people as being particularly helpful.
91 ;; Andy Norman's ange-ftp was the inspiration for the original jka-compr for
92 ;; Version 18 of Emacs.
94 ;; After I had made progress on the original jka-compr for V18, I learned of a
95 ;; package written by Kazushi Jam Marukawa, called jam-zcat, that did exactly
96 ;; what I was trying to do. I looked over the jam-zcat source code and
97 ;; probably got some ideas from it.
102 (defvar jka-compr-shell
"sh"
103 "*Shell to be used for calling compression programs.
104 The value of this variable only matters if you want to discard the
105 stderr of a compression/decompression program (see the documentation
106 for `jka-compr-compression-info-list').")
109 (defvar jka-compr-use-shell t
)
112 ;;; I have this defined so that .Z files are assumed to be in unix
113 ;;; compress format; and .gz files, in gzip format.
114 (defvar jka-compr-compression-info-list
116 ;; compr-message compr-prog compr-args
117 ;; uncomp-message uncomp-prog uncomp-args
118 ;; can-append auto-mode-flag]
119 '(["\\.Z\\(~\\|\\.~[0-9]+~\\)?\\'"
120 "compressing" "compress" ("-c")
121 "uncompressing" "uncompress" ("-c")
124 "zipping" "gzip" ("-c" "-q")
125 "unzipping" "gzip" ("-c" "-q" "-d")
127 ["\\.gz\\(~\\|\\.~[0-9]+~\\)?\\'"
128 "zipping" "gzip" ("-c" "-q")
129 "unzipping" "gzip" ("-c" "-q" "-d")
132 "List of vectors that describe available compression techniques.
133 Each element, which describes a compression technique, is a vector of
134 the form [REGEXP COMPRESS-MSG COMPRESS-PROGRAM COMPRESS-ARGS
135 UNCOMPRESS-MSG UNCOMPRESS-PROGRAM UNCOMPRESS-ARGS
136 APPEND-FLAG EXTENSION], where:
138 regexp is a regexp that matches filenames that are
139 compressed with this format
141 compress-msg is the message to issue to the user when doing this
142 type of compression (nil means no message)
144 compress-program is a program that performs this compression
146 compress-args is a list of args to pass to the compress program
148 uncompress-msg is the message to issue to the user when doing this
149 type of uncompression (nil means no message)
151 uncompress-program is a program that performs this compression
153 uncompress-args is a list of args to pass to the uncompress program
155 append-flag is non-nil if this compression technique can be
158 auto-mode flag non-nil means strip the regexp from file names
159 before attempting to set the mode.
161 Because of the way `call-process' is defined, discarding the stderr output of
162 a program adds the overhead of starting a shell each time the program is
165 (defvar jka-compr-mode-alist-additions
166 (list (cons "\\.tgz\\'" 'tar-mode
))
167 "A list of pairs to add to auto-mode-alist when jka-compr is installed.")
169 (defvar jka-compr-file-name-handler-entry
171 "The entry in `file-name-handler-alist' used by the jka-compr I/O functions.")
173 ;;; Functions for accessing the return value of jka-compr-get-compression-info
174 (defun jka-compr-info-regexp (info) (aref info
0))
175 (defun jka-compr-info-compress-message (info) (aref info
1))
176 (defun jka-compr-info-compress-program (info) (aref info
2))
177 (defun jka-compr-info-compress-args (info) (aref info
3))
178 (defun jka-compr-info-uncompress-message (info) (aref info
4))
179 (defun jka-compr-info-uncompress-program (info) (aref info
5))
180 (defun jka-compr-info-uncompress-args (info) (aref info
6))
181 (defun jka-compr-info-can-append (info) (aref info
7))
182 (defun jka-compr-info-strip-extension (info) (aref info
8))
185 (defun jka-compr-get-compression-info (filename)
186 "Return information about the compression scheme of FILENAME.
187 The determination as to which compression scheme, if any, to use is
188 based on the filename itself and `jka-compr-compression-info-list'."
189 (catch 'compression-info
190 (let ((case-fold-search nil
))
192 (function (lambda (x)
193 (and (string-match (jka-compr-info-regexp x
) filename
)
194 (throw 'compression-info x
))))
195 jka-compr-compression-info-list
)
199 (put 'compression-error
'error-conditions
'(compression-error file-error error
))
202 (defvar jka-compr-acceptable-retval-list
'(0 2 141))
205 (defun jka-compr-error (prog args infile message
&optional errfile
)
207 (let ((errbuf (get-buffer-create " *jka-compr-error*"))
208 (curbuf (current-buffer)))
210 (widen) (erase-buffer)
211 (insert (format "Error while executing \"%s %s < %s\"\n\n"
213 (mapconcat 'identity args
" ")
217 (insert-file-contents errfile
))
220 (display-buffer errbuf
))
222 (signal 'compression-error
(list "Opening input file" (format "error %s" message
) infile
)))
225 (defvar jka-compr-dd-program
229 (defvar jka-compr-dd-blocksize
256)
232 (defun jka-compr-partial-uncompress (prog message args infile beg len
)
233 "Call program PROG with ARGS args taking input from INFILE.
234 Fourth and fifth args, BEG and LEN, specify which part of the output
235 to keep: LEN chars starting BEG chars from the beginning."
236 (let* ((skip (/ beg jka-compr-dd-blocksize
))
237 (prefix (- beg
(* skip jka-compr-dd-blocksize
)))
238 (count (and len
(1+ (/ (+ len prefix
) jka-compr-dd-blocksize
))))
240 (err-file (jka-compr-make-temp-name))
241 (run-string (format "%s %s 2> %s | %s bs=%d skip=%d %s 2> /dev/null"
243 (mapconcat 'identity args
" ")
246 jka-compr-dd-blocksize
248 ;; dd seems to be unreliable about
249 ;; providing the last block. So, always
250 ;; read one more than you think you need.
251 (if count
(concat "count=" (1+ count
)) ""))))
254 (or (memq (call-process jka-compr-shell
257 jka-compr-acceptable-retval-list
)
259 (jka-compr-error prog args infile message err-file
))
261 (jka-compr-delete-temp-file err-file
))
263 ;; Delete the stuff after what we want, if there is any.
266 (< (+ start prefix len
) (point))
267 (delete-region (+ start prefix len
) (point)))
269 ;; Delete the stuff before what we want.
270 (delete-region start
(+ start prefix
))))
273 (defun jka-compr-call-process (prog message infile output temp args
)
274 (if jka-compr-use-shell
276 (let ((err-file (jka-compr-make-temp-name)))
281 (call-process jka-compr-shell infile
282 (if (stringp output
) nil output
)
285 (format "%s %s 2> %s %s"
287 (mapconcat 'identity args
" ")
292 jka-compr-acceptable-retval-list
)
294 (jka-compr-error prog args infile message err-file
))
296 (jka-compr-delete-temp-file err-file
)))
302 (if (stringp output
) temp output
)
305 (jka-compr-error prog args infile message
))
307 (and (stringp output
)
308 (let ((cbuf (current-buffer)))
310 (write-region (point-min) (point-max) output
)
312 (set-buffer cbuf
)))))
315 ;;; Support for temp files. Much of this was inspired if not lifted
318 (defvar jka-compr-temp-name-template
319 (expand-file-name "jka-com"
320 (or (getenv "TMPDIR") "/tmp/"))
321 "Prefix added to all temp files created by jka-compr.
322 There should be no more than seven characters after the final `/'")
324 (defvar jka-compr-temp-name-table
(make-vector 31 nil
))
326 (defun jka-compr-make-temp-name (&optional local-copy
)
327 "This routine will return the name of a new file."
330 (template (concat jka-compr-temp-name-template
"aa"))
331 (lastpos (1- (length template
)))
337 (aset template lastpos lastchar
)
338 (setq file
(concat (make-temp-name template
) "#"))
339 (setq entry
(intern file jka-compr-temp-name-table
))
340 (if (or (get entry
'active
)
341 (file-exists-p file
))
344 (setq lastchar
(1+ lastchar
))
347 (setq prevchar
(1+ prevchar
))
350 (error "Can't allocate temp file.")
351 (aset template
(1- lastpos
) prevchar
)))))
353 (put entry
'active
(not local-copy
))
354 (setq not-done nil
)))
359 (defun jka-compr-delete-temp-file (temp)
361 (put (intern temp jka-compr-temp-name-table
)
369 (defun jka-compr-write-region (start end file
&optional append visit
)
370 (let* ((filename (expand-file-name file
))
371 (visit-file (if (stringp visit
) (expand-file-name visit
) filename
))
372 (info (jka-compr-get-compression-info visit-file
)))
376 (let ((can-append (jka-compr-info-can-append info
))
377 (compress-program (jka-compr-info-compress-program info
))
378 (compress-message (jka-compr-info-compress-message info
))
379 (uncompress-program (jka-compr-info-uncompress-program info
))
380 (uncompress-message (jka-compr-info-uncompress-message info
))
381 (compress-args (jka-compr-info-compress-args info
))
382 (uncompress-args (jka-compr-info-uncompress-args info
))
383 (base-name (file-name-nondirectory visit-file
))
384 temp-file cbuf temp-buffer
)
386 (setq cbuf
(current-buffer)
387 temp-buffer
(get-buffer-create " *jka-compr-wr-temp*"))
388 (set-buffer temp-buffer
)
389 (widen) (erase-buffer)
394 (file-exists-p filename
))
396 (let* ((local-copy (file-local-copy filename
))
397 (local-file (or local-copy filename
)))
399 (setq temp-file local-file
))
401 (setq temp-file
(jka-compr-make-temp-name)))
405 (message "%s %s..." compress-message base-name
))
407 (jka-compr-run-real-handler 'write-region
408 (list start end temp-file t
'dont
))
410 (jka-compr-call-process compress-program
411 (concat compress-message
418 (set-buffer temp-buffer
)
419 (jka-compr-run-real-handler 'write-region
420 (list (point-min) (point-max)
422 (and append can-append
) 'dont
))
426 (jka-compr-delete-temp-file temp-file
)
430 (message "%s %s...done" compress-message base-name
))
434 (setq buffer-file-name filename
)
435 (set-visited-file-modtime))
437 (setq buffer-file-name visit
)
438 (let ((buffer-file-name filename
))
439 (set-visited-file-modtime))))
441 (and (or (eq visit t
)
444 (message "Wrote %s" visit-file
))
448 (jka-compr-run-real-handler 'write-region
449 (list start end filename append visit
)))))
452 (defun jka-compr-insert-file-contents (file &optional visit beg end replace
)
453 (barf-if-buffer-read-only)
457 (error "Attempt to visit less than an entire file"))
459 (let* ((filename (expand-file-name file
))
460 (info (jka-compr-get-compression-info filename
)))
464 (let ((uncompress-message (jka-compr-info-uncompress-message info
))
465 (uncompress-program (jka-compr-info-uncompress-program info
))
466 (uncompress-args (jka-compr-info-uncompress-args info
))
467 (base-name (file-name-nondirectory filename
))
470 (jka-compr-run-real-handler 'file-local-copy
(list filename
)))
474 (setq local-file
(or local-copy filename
))
478 (setq buffer-file-name filename
))
480 (unwind-protect ; to make sure local-copy gets deleted
486 (message "%s %s..." uncompress-message base-name
))
488 (condition-case error-code
492 (goto-char (point-min)))
495 (jka-compr-partial-uncompress uncompress-program
496 (concat uncompress-message
504 ;; If visiting, bind off buffer-file-name so that
505 ;; file-locking will not ask whether we should
506 ;; really edit the buffer.
507 (let ((buffer-file-name
508 (if visit nil buffer-file-name
)))
509 (jka-compr-call-process uncompress-program
510 (concat uncompress-message
516 (setq size
(- (point) start
))
518 (let* ((del-beg (point))
519 (del-end (+ del-beg size
)))
520 (delete-region del-beg
521 (min del-end
(point-max)))))
524 (if (and (eq (car error-code
) 'file-error
)
525 (eq (nth 3 error-code
) local-file
))
527 (setq notfound error-code
)
529 (cons "Opening input file"
530 (nthcdr 2 error-code
))))
531 (signal (car error-code
) (cdr error-code
))))))
535 (file-exists-p local-copy
)
536 (delete-file local-copy
)))
542 (setq buffer-file-name filename
)
543 (set-visited-file-modtime)))
547 (message "%s %s...done" uncompress-message base-name
))
553 (cons "Opening input file" (nth 2 notfound
))))
555 ;; Run the functions that insert-file-contents would.
556 (let ((p after-insert-file-functions
)
559 (setq insval
(funcall (car p
) size
))
562 (or (integerp insval
)
563 (signal 'wrong-type-argument
564 (list 'integerp insval
)))
568 (list filename size
))
570 (jka-compr-run-real-handler 'insert-file-contents
571 (list file visit beg end replace
)))))
574 (defun jka-compr-file-local-copy (file)
575 (let* ((filename (expand-file-name file
))
576 (info (jka-compr-get-compression-info filename
)))
580 (let ((uncompress-message (jka-compr-info-uncompress-message info
))
581 (uncompress-program (jka-compr-info-uncompress-program info
))
582 (uncompress-args (jka-compr-info-uncompress-args info
))
583 (base-name (file-name-nondirectory filename
))
585 (jka-compr-run-real-handler 'file-local-copy
(list filename
)))
586 (temp-file (jka-compr-make-temp-name t
))
587 (temp-buffer (get-buffer-create " *jka-compr-flc-temp*"))
589 (cbuf (current-buffer))
592 (setq local-file
(or local-copy filename
))
600 (message "%s %s..." uncompress-message base-name
))
602 (set-buffer temp-buffer
)
604 (jka-compr-call-process uncompress-program
605 (concat uncompress-message
614 (message "%s %s...done" uncompress-message base-name
))
617 (point-min) (point-max) temp-file nil
'dont
))
621 (file-exists-p local-copy
)
622 (delete-file local-copy
))
625 (kill-buffer temp-buffer
))
629 (jka-compr-run-real-handler 'file-local-copy
(list filename
)))))
632 ;;; Support for loading compressed files.
633 (defun jka-compr-load (file &optional noerror nomessage nosuffix
)
634 "Documented as original."
636 (let* ((local-copy (jka-compr-file-local-copy file
))
637 (load-file (or local-copy file
)))
641 (let (inhibit-file-name-operation
642 inhibit-file-name-handlers
)
644 (message "Loading %s..." file
))
646 (let ((load-force-doc-strings t
))
647 (load load-file noerror t t
))
650 (message "Loading %s...done." file
)))
652 (jka-compr-delete-temp-file local-copy
))
656 (defun jka-compr-byte-compiler-base-file-name (file)
657 (let ((info (jka-compr-get-compression-info file
)))
658 (if (and info
(jka-compr-info-strip-extension info
))
660 (substring file
0 (string-match (jka-compr-info-regexp info
) file
)))
663 (put 'write-region
'jka-compr
'jka-compr-write-region
)
664 (put 'insert-file-contents
'jka-compr
'jka-compr-insert-file-contents
)
665 (put 'file-local-copy
'jka-compr
'jka-compr-file-local-copy
)
666 (put 'load
'jka-compr
'jka-compr-load
)
667 (put 'byte-compiler-base-file-name
'jka-compr
668 'jka-compr-byte-compiler-base-file-name
)
670 (defun jka-compr-handler (operation &rest args
)
672 (let ((jka-op (get operation
'jka-compr
)))
675 (jka-compr-run-real-handler operation args
)))))
677 ;; If we are given an operation that we don't handle,
678 ;; call the Emacs primitive for that operation,
679 ;; and manipulate the inhibit variables
680 ;; to prevent the primitive from calling our handler again.
681 (defun jka-compr-run-real-handler (operation args
)
682 (let ((inhibit-file-name-handlers
683 (cons 'jka-compr-handler
684 (and (eq inhibit-file-name-operation operation
)
685 inhibit-file-name-handlers
)))
686 (inhibit-file-name-operation operation
))
687 (apply operation args
)))
689 ;;;###autoload(defun auto-compression-mode (&optional arg)
691 ;;;###autoloadToggle automatic file compression and uncompression.
692 ;;;###autoloadWith prefix argument ARG, turn auto compression on if positive, else off.
693 ;;;###autoloadReturns the new status of auto compression (non-nil means on)."
694 ;;;###autoload (interactive "P")
695 ;;;###autoload (if (not (fboundp 'jka-compr-installed-p))
696 ;;;###autoload (progn
697 ;;;###autoload (require 'jka-compr)
698 ;;;###autoload ;; That turned the mode on, so make it initially off.
699 ;;;###autoload (toggle-auto-compression)))
700 ;;;###autoload (toggle-auto-compression arg t))
702 (defun toggle-auto-compression (&optional arg message
)
703 "Toggle automatic file compression and uncompression.
704 With prefix argument ARG, turn auto compression on if positive, else off.
705 Returns the new status of auto compression (non-nil means on).
706 If the argument MESSAGE is non-nil, it means to print a message
707 saying whether the mode is now on or off."
709 (let* ((installed (jka-compr-installed-p))
712 (or (eq arg t
) (listp arg
) (and (integerp arg
) (> arg
0))))))
715 ((and flag installed
) t
) ; already installed
717 ((and (not flag
) (not installed
)) nil
) ; already not installed
723 (jka-compr-uninstall)))
728 (message "Automatic file (de)compression is now ON.")
729 (message "Automatic file (de)compression is now OFF.")))
733 (defun jka-compr-build-file-regexp ()
737 'jka-compr-info-regexp
738 jka-compr-compression-info-list
743 (defun jka-compr-install ()
745 This adds entries to `file-name-handler-alist' and `auto-mode-alist'
746 and `inhibit-first-line-modes-suffixes'."
748 (setq jka-compr-file-name-handler-entry
749 (cons (jka-compr-build-file-regexp) 'jka-compr-handler
))
751 (setq file-name-handler-alist
(cons jka-compr-file-name-handler-entry
752 file-name-handler-alist
))
755 (function (lambda (x)
756 (and (jka-compr-info-strip-extension x
)
757 ;; Make entries in auto-mode-alist so that modes
758 ;; are chosen right according to the file names
760 (setq auto-mode-alist
761 (cons (list (jka-compr-info-regexp x
)
764 ;; Also add these regexps to
765 ;; inhibit-first-line-modes-suffixes, so that a
766 ;; -*- line in the first file of a compressed tar
767 ;; file doesn't override tar-mode.
768 (setq inhibit-first-line-modes-suffixes
769 (cons (jka-compr-info-regexp x
)
770 inhibit-first-line-modes-suffixes
)))))
771 jka-compr-compression-info-list
)
772 (setq auto-mode-alist
773 (append auto-mode-alist jka-compr-mode-alist-additions
)))
776 (defun jka-compr-uninstall ()
777 "Uninstall jka-compr.
778 This removes the entries in `file-name-handler-alist' and `auto-mode-alist'
779 and `inhibit-first-line-modes-suffixes' that were added
780 by `jka-compr-installed'."
781 ;; Delete from inhibit-first-line-modes-suffixes
782 ;; what jka-compr-install added.
784 (function (lambda (x)
785 (and (jka-compr-info-strip-extension x
)
786 (setq inhibit-first-line-modes-suffixes
787 (delete (jka-compr-info-regexp x
)
788 inhibit-first-line-modes-suffixes
)))))
789 jka-compr-compression-info-list
)
791 (let* ((fnha (cons nil file-name-handler-alist
))
795 (if (eq (cdr (car (cdr last
))) 'jka-compr-handler
)
796 (setcdr last
(cdr (cdr last
)))
797 (setq last
(cdr last
))))
799 (setq file-name-handler-alist
(cdr fnha
)))
801 (let* ((ama (cons nil auto-mode-alist
))
806 (setq entry
(car (cdr last
)))
807 (if (or (member entry jka-compr-mode-alist-additions
)
808 (and (consp (cdr entry
))
809 (eq (nth 2 entry
) 'jka-compr
)))
810 (setcdr last
(cdr (cdr last
)))
811 (setq last
(cdr last
))))
813 (setq auto-mode-alist
(cdr ama
))))
816 (defun jka-compr-installed-p ()
817 "Return non-nil if jka-compr is installed.
818 The return value is the entry in `file-name-handler-alist' for jka-compr."
820 (let ((fnha file-name-handler-alist
)
823 (while (and fnha
(not installed
))
824 (and (eq (cdr (car fnha
)) 'jka-compr-handler
)
825 (setq installed
(car fnha
)))
826 (setq fnha
(cdr fnha
)))
831 ;;; Add the file I/O hook if it does not already exist.
832 ;;; Make sure that jka-compr-file-name-handler-entry is eq to the
833 ;;; entry for jka-compr in file-name-handler-alist.
834 (and (jka-compr-installed-p)
835 (jka-compr-uninstall))
842 ;; jka-compr.el ends here.