(defvar uncompress-program "gunzip"
"Program to use for uncompression.")
(defun uncompress-backup-file ()
(and buffer-file-name make-backup-files (not buffer-backed-up)
(not (file-exists-p buffer-file-name))
(call-process uncompress-program nil nil nil buffer-file-name))
nil)
(or (assoc "\\.Z$" auto-mode-alist)
(setq auto-mode-alist
(cons '("\\.Z$" . uncompress-while-visiting) auto-mode-alist)))
(or (assoc "\\.gz$" auto-mode-alist)
(setq auto-mode-alist
(cons '("\\.gz$" . uncompress-while-visiting) auto-mode-alist)))
(or (assoc "\\.tgz$" auto-mode-alist)
(setq auto-mode-alist
(cons '("\\.tgz$" . uncompress-while-visiting) auto-mode-alist)))
(defun uncompress-while-visiting ()
"Temporary \"major mode\" used for .Z and .gz files, to uncompress them.
It then selects a major mode from the uncompressed file name and contents."
(if (and (not (null buffer-file-name))
(string-match "\\.Z$" buffer-file-name))
(set-visited-file-name
(substring buffer-file-name 0 (match-beginning 0)))
(if (and (not (null buffer-file-name))
(string-match "\\.gz$" buffer-file-name))
(set-visited-file-name
(substring buffer-file-name 0 (match-beginning 0)))
(if (and (not (null buffer-file-name))
(string-match "\\.tgz$" buffer-file-name))
(set-visited-file-name
(concat (substring buffer-file-name 0 (match-beginning 0)) ".tar")))))
(message "Uncompressing...")
(let ((buffer-read-only nil)
(coding-system-for-write 'no-conversion)
(coding-system-for-read
(car (find-operation-coding-system
'insert-file-contents
buffer-file-name t))))
(shell-command-on-region (point-min) (point-max) uncompress-program t))
(goto-char (point-min))
(message "Uncompressing...done")
(set-buffer-modified-p nil)
(make-local-variable 'write-file-hooks)
(or (memq 'uncompress-backup-file write-file-hooks)
(setq write-file-hooks (cons 'uncompress-backup-file write-file-hooks)))
(normal-mode))
(or (memq 'find-compressed-version find-file-not-found-hooks)
(setq find-file-not-found-hooks
(cons 'find-compressed-version find-file-not-found-hooks)))
(defun find-compressed-version ()
"Hook to read and uncompress the compressed version of a file."
(let (name)
(if (file-exists-p (setq name (concat buffer-file-name ".Z")))
(setq buffer-file-name name)
(if (file-exists-p (setq name (concat buffer-file-name ".gz")))
(setq buffer-file-name name)))
(if (eq name buffer-file-name)
(progn
(insert-file-contents buffer-file-name t)
(goto-char (point-min))
t))))
(provide 'uncompress)