graham@r3.cs.man.ac.uk (01/04/90)
This is a repost prompted by RMS's message re copyright, since I
inadvertently omitted the copyright notice from my previous posting.
It also fixes a bug by replacing a call to shell-command-on-region by
one to call-process-region.
Graham Gough
----------------------------------------------------------
Graham D. Gough, Department of Computer Science,
University of Manchester, Oxford Road, Manchester, M13 9PL, U.K.
Tel: (+44) 61-275 6277
JANET: graham@uk.ac.man.cs USENET: ..ukc!man.cs.r3!graham
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;;
;; zcat.el
;;
;; Copyright (C) 1989 Graham D. Gough
;;
;; This file is not part of GNU Emacs, however, GNU copyleft applies
;;
;; Visiting compressed files.
;;
;; Graham Gough (graham@uk.ac.man.cs.ux) 13/5/87
;;
;; To use just load via .emacs, everything else is automatic
;;
(or (assoc "\\.Z$" auto-mode-alist)
(setq auto-mode-alist (append auto-mode-alist '(("\\.Z$" . zcat-buffer)))))
(defvar delete-compressed-files t "*Non-nil means delete the compressed version
of a file when a buffer is saved. Only has effect if original file visited
was compressed.")
(defun delete-compressed-file ()
" Deletes (on confirmation) compressed version of file associated with
current buffer"
(interactive)
(let ((fname (concat (buffer-file-name) ".Z"))
ret)
(if (file-exists-p fname)
(progn
(setq answer (yes-or-no-p (concat "Delete compressed file (" fname ")? ")))
(if answer
(condition-case ()
(delete-file fname)
(error
(message "Can't delete compressed file.")
(setq ret t))))))
nil))
(defun zcat-buffer ()
" Uncompresses contents of buffer, respecting read-only status. Changes
buffer-name, visited-file-name and mode appropriately. If buffer is saved,
compressed file is (optionally) deleted.
Bug: Doesn't find an existing uncompressed buffer, creates a new one"
(interactive)
(let ((buf-stat buffer-read-only) ; remember read-only status
(new-buf-name (substring (buffer-name) 0 -2)) ; get new buffer name
(new-buf-fname (substring (buffer-file-name) 0 -2))) ; and file name
(setq buffer-read-only nil)
(message "Uncompressing %s .." (buffer-name))
(call-process-region (point-min) (point-max) "zcat" t t)
(message "Done")
(setq buffer-read-only buf-stat) ; reinstate original
; buffer-read-only status
(rename-buffer
(let ((newbname new-buf-name)
(counter 1))
(while (get-buffer newbname)
(setq newbname
(concat new-buf-name "<" (prin1-to-string counter) ">"))
(setq counter (1+ counter)))
newbname)) ; generate appropriate name.
(set-visited-file-name new-buf-fname)
(set-auto-mode)
(if (not delete-compressed-files)
nil
(make-variable-buffer-local 'write-file-hooks)
(setq write-file-hooks
(append write-file-hooks '(delete-compressed-file))))
(set-buffer-modified-p nil) ; this means that auto-saves
; and saves only take place
; if buffer is really modified
(goto-char (point-min))))