Initial revision

1 files changed, 47 insertions, 0 deletions

diff --git a/lisp/uncompress.el b/lisp/uncompress.el
new file mode 100644
index 00000000000..6897c7c3ccb
--- /dev/null
+++ b/lisp/uncompress.el
@@ -0,0 +1,47 @@
+;; When we are about to make a backup file,
+;; uncompress the file we visited
+;; so that making the backup can work properly.
+;; This is used as a write-file-hook.
+
+(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" 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)))
+
+(defun uncompress-while-visiting ()
+  "Temporary \"major mode\" used for .Z files, to uncompress the contents.
+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))))
+  (message "Uncompressing...")
+  (let ((buffer-read-only nil))
+    (shell-command-on-region (point-min) (point-max) "uncompress" t))
+  (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."
+  ;; Just pretend we had visited the compressed file,
+  ;; and uncompress-while-visiting will do the rest.
+  (if (file-exists-p (concat buffer-file-name ".Z"))
+      (progn
+        (setq buffer-file-name (concat buffer-file-name ".Z"))
+        (insert-file-contents buffer-file-name t)
+        (goto-char (point-min))
+        (setq error nil)
+        t)))