-;;; diff.el --- "DIFF" mode for handling output from unix diff utility.
+;;; diff.el --- run `diff' in compilation-mode
-;; Copyright (C) 1990 Free Software Foundation, Inc.
+;; Copyright (C) 1992, 1994, 1996, 2001, 2002, 2003, 2004,
+;; 2005, 2006 Free Software Foundation, Inc.
-;; Author: Frank P. Bresz <fpb@ittc.wec.com>
;; Maintainer: FSF
-;; Created: 27 Jan 1989
-;; Keyword: unix, tools
+;; Keywords: unix, tools
;; This file is part of GNU Emacs.
;; GNU General Public License for more details.
;; You should have received a copy of the GNU General Public License
-;; along with GNU Emacs; see the file COPYING. If not, write to
-;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
+;; along with GNU Emacs; see the file COPYING. If not, write to the
+;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+;; Boston, MA 02110-1301, USA.
;;; Commentary:
-;; todo: diff-switches flexibility:
-;; (defconst diff-switches-function
-;; '(lambda (file)
-;; (if (string-match "\\.el$" file)
-;; "-c -F\"^(\""
-;; "-p"))
-;; "Function to return switches to pass to the `diff' utility, in \\[diff].
-;; This function is called with one arg, a file name, and returns a string
-;; containing 0 or more arguments which are passed on to `diff'.
-;; NOTE: This is not an ordinary hook; it may not be a list of functions.")
-
-;; - fpb@ittc.wec.com - Sep 25, 1990
-;; Added code to support sccs diffing.
-;; also fixed one minor glitch in the
-;; search for the pattern. If you only 1 addition you won't find the end
-;; of the pattern (minor)
+;; This package helps you explore differences between files, using the
+;; UNIX command diff(1). The commands are `diff' and `diff-backup'.
+;; You can specify options with `diff-switches'.
;;; Code:
-(defvar diff-switches nil
- "*A list of switches to pass to the diff program.")
-
-(defvar diff-search-pattern "^\\([0-9]\\|\\*\\*\\*\\*\\*\\*\\*\\*\\*\\*\\*\\*\\*\\*\\*\\)"
- "Regular expression that delineates difference regions in diffs.")
+(defgroup diff nil
+ "Comparing files with `diff'."
+ :group 'tools)
-(defvar diff-rcs-extension ",v"
- "*Extension to find RCS file, some systems do not use ,v")
+;;;###autoload
+(defcustom diff-switches "-c"
+ "*A string or list of strings specifying switches to be passed to diff."
+ :type '(choice string (repeat string))
+ :group 'diff)
-;; Initialize the keymap if it isn't already
-(if (boundp 'diff-mode-map)
- nil
- (setq diff-mode-map (make-keymap))
- (suppress-keymap diff-mode-map)
- (define-key diff-mode-map "?" 'describe-mode)
- (define-key diff-mode-map "." 'diff-beginning-of-diff)
- (define-key diff-mode-map " " 'scroll-up)
- (define-key diff-mode-map "\177" 'scroll-down)
- (define-key diff-mode-map "n" 'diff-next-difference)
- (define-key diff-mode-map "p" 'diff-previous-difference)
- (define-key diff-mode-map "j" 'diff-show-difference))
+;;;###autoload
+(defcustom diff-command "diff"
+ "*The command to use to run diff."
+ :type 'string
+ :group 'diff)
+
+(defvar diff-old-temp-file nil
+ "This is the name of a temp file to be deleted after diff finishes.")
+(defvar diff-new-temp-file nil
+ "This is the name of a temp file to be deleted after diff finishes.")
+
+;; prompt if prefix arg present
+(defun diff-switches ()
+ (if current-prefix-arg
+ (read-string "Diff switches: "
+ (if (stringp diff-switches)
+ diff-switches
+ (mapconcat 'identity diff-switches " ")))))
+
+(defun diff-sentinel (code)
+ "Code run when the diff process exits.
+CODE is the exit code of the process. It should be 0 iff no diffs were found."
+ (if diff-old-temp-file (delete-file diff-old-temp-file))
+ (if diff-new-temp-file (delete-file diff-new-temp-file))
+ (save-excursion
+ (goto-char (point-max))
+ (insert (format "\nDiff finished%s. %s\n"
+ (if (equal 0 code) " (no differences)" "")
+ (current-time-string)))))
;;;###autoload
-(defun diff (old new)
+(defun diff (old new &optional switches no-async)
"Find and display the differences between OLD and NEW files.
-Interactively the current buffer's file name is the default for for NEW
-and a backup file for NEW is the default for OLD."
+Interactively the current buffer's file name is the default for NEW
+and a backup file for NEW is the default for OLD.
+If NO-ASYNC is non-nil, call diff synchronously.
+With prefix arg, prompt for diff switches."
(interactive
(let (oldf newf)
- (reverse
- (list
- (setq newf (buffer-file-name)
- newf (if (and newf (file-exists-p newf))
- (read-file-name
- (concat "Diff new file: ("
- (file-name-nondirectory newf) ") ")
- nil newf t)
- (read-file-name "Diff new file: " nil nil t)))
- (setq oldf (file-newest-backup newf)
- oldf (if (and oldf (file-exists-p oldf))
- (read-file-name
- (concat "Diff original file: ("
- (file-name-nondirectory oldf) ") ")
- (file-name-directory oldf) oldf t)
- (read-file-name "Diff original file: "
- (file-name-directory newf) nil t)))))))
- (message "Comparing files %s %s..." new old)
+ (setq newf (buffer-file-name)
+ newf (if (and newf (file-exists-p newf))
+ (read-file-name
+ (concat "Diff new file (default "
+ (file-name-nondirectory newf) "): ")
+ nil newf t)
+ (read-file-name "Diff new file: " nil nil t)))
+ (setq oldf (file-newest-backup newf)
+ oldf (if (and oldf (file-exists-p oldf))
+ (read-file-name
+ (concat "Diff original file (default "
+ (file-name-nondirectory oldf) "): ")
+ (file-name-directory oldf) oldf t)
+ (read-file-name "Diff original file: "
+ (file-name-directory newf) nil t)))
+ (list oldf newf (diff-switches))))
(setq new (expand-file-name new)
old (expand-file-name old))
- (diff-internal-diff "diff" (append diff-switches (list new old)) nil))
+ (or switches (setq switches diff-switches)) ; If not specified, use default.
+ (let* ((old-alt (file-local-copy old))
+ (new-alt (file-local-copy new))
+ (command
+ (mapconcat 'identity
+ `(,diff-command
+ ;; Use explicitly specified switches
+ ,@(if (listp switches) switches (list switches))
+ ,@(if (or old-alt new-alt)
+ (list "-L" old "-L" new))
+ ,(shell-quote-argument (or old-alt old))
+ ,(shell-quote-argument (or new-alt new)))
+ " "))
+ (buf (get-buffer-create "*Diff*"))
+ (thisdir default-directory)
+ proc)
+ (save-excursion
+ (display-buffer buf)
+ (set-buffer buf)
+ (setq buffer-read-only nil)
+ (buffer-disable-undo (current-buffer))
+ (erase-buffer)
+ (buffer-enable-undo (current-buffer))
+ (diff-mode)
+ (set (make-local-variable 'revert-buffer-function)
+ `(lambda (ignore-auto noconfirm)
+ (diff ',old ',new ',switches ',no-async)))
+ (set (make-local-variable 'diff-old-temp-file) old-alt)
+ (set (make-local-variable 'diff-new-temp-file) new-alt)
+ (setq default-directory thisdir)
+ (insert command "\n")
+ (if (and (not no-async) (fboundp 'start-process))
+ (progn
+ (setq proc (start-process "Diff" buf shell-file-name
+ shell-command-switch command))
+ (set-process-sentinel
+ proc (lambda (proc msg)
+ (with-current-buffer (process-buffer proc)
+ (diff-sentinel (process-exit-status proc))))))
+ ;; Async processes aren't available.
+ (diff-sentinel
+ (call-process shell-file-name nil buf nil
+ shell-command-switch command))))
+ buf))
-(defun diff-backup (file)
+;;;###autoload
+(defun diff-backup (file &optional switches)
"Diff this file with its backup file or vice versa.
Uses the latest backup, if there are several numerical backups.
If this file is a backup, diff it with its original.
-The backup file is the first file given to `diff'."
- (interactive "fDiff (file with backup): ")
+The backup file is the first file given to `diff'.
+With prefix arg, prompt for diff switches."
+ (interactive (list (read-file-name "Diff (file with backup): ")
+ (diff-switches)))
(let (bak ori)
(if (backup-file-name-p file)
(setq bak file
(setq bak (or (diff-latest-backup-file file)
(error "No backup found for %s" file))
ori file))
- (diff bak ori)))
+ (diff bak ori switches)))
(defun diff-latest-backup-file (fn) ; actually belongs into files.el
"Return the latest existing backup of FILE, or nil."
- ;; First try simple backup, then the highest numbered of the
- ;; numbered backups.
- ;; Ignore the value of version-control because we look for existing
- ;; backups, which maybe were made earlier or by another user with
- ;; a different value of version-control.
- (setq fn (expand-file-name fn))
- (or
- (let ((bak (make-backup-file-name fn)))
- (if (file-exists-p bak) bak))
- (let* ((dir (file-name-directory fn))
- (base-versions (concat (file-name-nondirectory fn) ".~"))
- (bv-length (length base-versions)))
- (concat dir
- (car (sort
- (file-name-all-completions base-versions dir)
- ;; bv-length is a fluid var for backup-extract-version:
- (function
- (lambda (fn1 fn2)
- (> (backup-extract-version fn1)
- (backup-extract-version fn2))))))))))
-
-(defun diff-internal-diff (diff-command sw strip)
- (let ((buffer-read-only nil))
- (with-output-to-temp-buffer "*Diff Output*"
- (buffer-disable-undo standard-output)
- (save-excursion
- (set-buffer standard-output)
- (erase-buffer)
- (apply 'call-process diff-command nil t nil sw)))
- (set-buffer "*Diff Output*")
- (goto-char (point-min))
- (while sw
- (if (string= (car sw) "-c")
- ;; strip leading filenames from context diffs
- (progn (forward-line 2) (delete-region (point-min) (point))))
- (if (and (string= (car sw) "-C") (string= "sccs" diff-command))
- ;; strip stuff from SCCS context diffs
- (progn (forward-line 2) (delete-region (point-min) (point))))
- (setq sw (cdr sw)))
- (if strip
- ;; strip stuff from SCCS context diffs
- (progn (forward-line strip) (delete-region (point-min) (point)))))
- (diff-mode)
- (if (string= "0" diff-total-differences)
- (let ((buffer-read-only nil))
- (insert (message "There are no differences.")))
- (narrow-to-region (point) (progn
- (forward-line 1)
- (if (re-search-forward diff-search-pattern
- nil t)
- (goto-char (match-beginning 0))
- (goto-char (point-max)))))
- (setq diff-current-difference "1")))
+ (let ((handler (find-file-name-handler fn 'diff-latest-backup-file)))
+ (if handler
+ (funcall handler 'diff-latest-backup-file fn)
+ (file-newest-backup fn))))
-;; Take a buffer full of Unix diff output and go into a mode to easily
-;; see the next and previous difference
-(defun diff-mode ()
- "Diff Mode is used by \\[diff] for perusing the output from the diff program.
-All normal editing commands are turned off. Instead, these are available:
-\\<diff-mode-map>
-\\[diff-beginning-of-diff] Move point to start of this difference.
-\\[scroll-up] Scroll to next screen of this difference.
-\\[scroll-down] Scroll to previous screen of this difference.
-\\[diff-next-difference] Move to Next Difference.
-\\[diff-previous-difference] Move to Previous Difference.
-\\[diff-show-difference] Jump to difference specified by numeric position.
-"
- (interactive)
- (use-local-map diff-mode-map)
- (setq buffer-read-only t
- major-mode 'diff-mode
- mode-name "Diff"
- mode-line-modified "--- "
- mode-line-process
- '(" " diff-current-difference "/" diff-total-differences))
- (make-local-variable 'diff-current-difference)
- (set (make-local-variable 'diff-total-differences)
- (int-to-string (diff-count-differences))))
-
-(defun diff-next-difference (n)
- "Go to the beginning of the next difference.
-Differences are delimited by `diff-search-pattern'."
- (interactive "p")
- (if (< n 0) (diff-previous-difference (- n))
- (if (zerop n) ()
- (goto-char (point-min))
- (forward-line 1) ; to get past the match for the start of this diff
- (widen)
- (if (re-search-forward diff-search-pattern nil 'move n)
- (let ((start (goto-char (match-beginning 0))))
- (forward-line 1)
- (if (re-search-forward diff-search-pattern nil 'move)
- (goto-char (match-beginning 0)))
- (narrow-to-region start (point))
- (setq diff-current-difference
- (int-to-string (+ n (string-to-int
- diff-current-difference)))))
- (re-search-backward diff-search-pattern nil)
- (narrow-to-region (point) (point-max))
- (message "No following differences.")
- (setq diff-current-difference diff-total-differences))
- (goto-char (point-min)))))
-
-(defun diff-previous-difference (n)
- "Go the the beginning of the previous difference.
-Differences are delimited by `diff-search-pattern'."
- (interactive "p")
- (if (< n 0) (diff-next-difference (- n))
- (if (zerop n) ()
- (goto-char (point-min))
- (widen)
- (if (re-search-backward diff-search-pattern nil 'move n)
- (setq diff-current-difference
- (int-to-string (- (string-to-int diff-current-difference) n)))
- (message "No previous differences.")
- (setq diff-current-difference "1"))
- (narrow-to-region (point) (progn
- (forward-line 1)
- (re-search-forward diff-search-pattern nil)
- (goto-char (match-beginning 0))))
- (goto-char (point-min)))))
-
-(defun diff-show-difference (n)
- "Show difference number N (prefix argument)."
- (interactive "p")
- (let ((cur (string-to-int diff-current-difference)))
- (cond ((or (= n cur)
- (zerop n)
- (not (natnump n))) ; should signal an error perhaps.
- ;; just redisplay.
- (goto-char (point-min)))
- ((< n cur)
- (diff-previous-difference (- cur n)))
- ((> n cur)
- (diff-next-difference (- n cur))))))
-
-(defun diff-beginning-of-diff ()
- "Go to beginning of current difference."
- (interactive)
- (goto-char (point-min)))
-
-;; This function counts up the number of differences in the buffer.
-(defun diff-count-differences ()
- "Count number of differences in the current buffer."
- (message "Counting differences...")
- (save-excursion
- (save-restriction
- (widen)
- (goto-char (point-min))
- (let ((cnt 0))
- (while (re-search-forward diff-search-pattern nil t)
- (setq cnt (1+ cnt)))
- (message "Counting differences...done (%d)" cnt)
- cnt))))
+(provide 'diff)
+;;; arch-tag: 7de2c29b-7ea5-4b85-9b9d-72dd860de2bd
;;; diff.el ends here