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Diffstat (limited to 'lisp/vc/diff.el')
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diff --git a/lisp/vc/diff.el b/lisp/vc/diff.el new file mode 100644 index 00000000000..0a853c5d902 --- /dev/null +++ b/lisp/vc/diff.el @@ -0,0 +1,218 @@ +;;; diff.el --- run `diff' in compilation-mode + +;; Copyright (C) 1992, 1994, 1996, 2001, 2002, 2003, 2004, 2005, 2006, +;; 2007, 2008, 2009, 2010, 2011 Free Software Foundation, Inc. + +;; Author: Frank Bresz +;; (according to authors.el) +;; Maintainer: FSF +;; Keywords: unix, vc, tools + +;; This file is part of GNU Emacs. + +;; GNU Emacs is free software: you can redistribute it and/or modify +;; it under the terms of the GNU General Public License as published by +;; the Free Software Foundation, either version 3 of the License, or +;; (at your option) any later version. + +;; GNU Emacs is distributed in the hope that it will be useful, +;; but WITHOUT ANY WARRANTY; without even the implied warranty of +;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +;; GNU General Public License for more details. + +;; You should have received a copy of the GNU General Public License +;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. + +;;; Commentary: + +;; 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: + +(eval-when-compile (require 'cl)) + +(defgroup diff nil + "Comparing files with `diff'." + :group 'tools) + +;;;###autoload +(defcustom diff-switches (purecopy "-c") + "A string or list of strings specifying switches to be passed to diff." + :type '(choice string (repeat string)) + :group 'diff) + +;;;###autoload +(defcustom diff-command (purecopy "diff") + "The command to use to run diff." + :type 'string + :group 'diff) + +;; 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 &optional old-temp-file new-temp-file) + "Code run when the diff process exits. +CODE is the exit code of the process. It should be 0 only if no diffs +were found." + (if old-temp-file (delete-file old-temp-file)) + (if new-temp-file (delete-file new-temp-file)) + (save-excursion + (goto-char (point-max)) + (let ((inhibit-read-only t)) + (insert (format "\nDiff finished%s. %s\n" + (cond ((equal 0 code) " (no differences)") + ((equal 2 code) " (diff error)") + (t "")) + (current-time-string)))))) + +;;;###autoload +(defun diff (old new &optional switches no-async) + "Find and display the differences between OLD and NEW files. +When called interactively, read OLD and NEW using the minibuffer; +the default for NEW is the current buffer's file name, and the +default for OLD is a backup file for NEW, if one exists. +If NO-ASYNC is non-nil, call diff synchronously. + +When called interactively with a prefix argument, prompt +interactively for diff switches. Otherwise, the switches +specified in `diff-switches' are passed to the diff command." + (interactive + (let* ((newf (if (and buffer-file-name (file-exists-p buffer-file-name)) + (read-file-name + (concat "Diff new file (default " + (file-name-nondirectory buffer-file-name) "): ") + nil buffer-file-name t) + (read-file-name "Diff new file: " nil nil t))) + (oldf (file-newest-backup newf))) + (setq 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)))) + (display-buffer + (diff-no-select old new switches no-async))) + +(defun diff-file-local-copy (file-or-buf) + (if (bufferp file-or-buf) + (with-current-buffer file-or-buf + (let ((tempfile (make-temp-file "buffer-content-"))) + (write-region nil nil tempfile nil 'nomessage) + tempfile)) + (file-local-copy file-or-buf))) + +(defun diff-no-select (old new &optional switches no-async buf) + ;; Noninteractive helper for creating and reverting diff buffers + (unless (bufferp new) (setq new (expand-file-name new))) + (unless (bufferp old) (setq old (expand-file-name old))) + (or switches (setq switches diff-switches)) ; If not specified, use default. + (unless (listp switches) (setq switches (list switches))) + (or buf (setq buf (get-buffer-create "*Diff*"))) + (let* ((old-alt (diff-file-local-copy old)) + (new-alt (diff-file-local-copy new)) + (command + (mapconcat 'identity + `(,diff-command + ;; Use explicitly specified switches + ,@switches + ,@(mapcar #'shell-quote-argument + (nconc + (when (or old-alt new-alt) + (list "-L" (if (stringp old) + old (prin1-to-string old)) + "-L" (if (stringp new) + new (prin1-to-string new)))) + (list (or old-alt old) + (or new-alt new))))) + " ")) + (thisdir default-directory)) + (with-current-buffer buf + (setq buffer-read-only t) + (buffer-disable-undo (current-buffer)) + (let ((inhibit-read-only t)) + (erase-buffer)) + (buffer-enable-undo (current-buffer)) + (diff-mode) + (set (make-local-variable 'revert-buffer-function) + (lexical-let ((old old) (new new) + (switches switches) + (no-async no-async)) + (lambda (ignore-auto noconfirm) + (diff-no-select old new switches no-async (current-buffer))))) + (setq default-directory thisdir) + (let ((inhibit-read-only t)) + (insert command "\n")) + (if (and (not no-async) (fboundp 'start-process)) + (let ((proc (start-process "Diff" buf shell-file-name + shell-command-switch command))) + (set-process-filter proc 'diff-process-filter) + (lexical-let ((old-alt old-alt) (new-alt new-alt)) + (set-process-sentinel + proc (lambda (proc msg) + (with-current-buffer (process-buffer proc) + (diff-sentinel (process-exit-status proc) + old-alt new-alt)))))) + ;; Async processes aren't available. + (let ((inhibit-read-only t)) + (diff-sentinel + (call-process shell-file-name nil buf nil + shell-command-switch command) + old-alt new-alt)))) + buf)) + +(defun diff-process-filter (proc string) + (with-current-buffer (process-buffer proc) + (let ((moving (= (point) (process-mark proc)))) + (save-excursion + ;; Insert the text, advancing the process marker. + (goto-char (process-mark proc)) + (let ((inhibit-read-only t)) + (insert string)) + (set-marker (process-mark proc) (point))) + (if moving (goto-char (process-mark proc)))))) + +;;;###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'. +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 + ori (file-name-sans-versions file)) + (setq bak (or (diff-latest-backup-file file) + (error "No backup found for %s" file)) + ori file)) + (diff bak ori switches))) + +(defun diff-latest-backup-file (fn) ; actually belongs into files.el + "Return the latest existing backup of FILE, or nil." + (let ((handler (find-file-name-handler fn 'diff-latest-backup-file))) + (if handler + (funcall handler 'diff-latest-backup-file fn) + (file-newest-backup fn)))) + +;;;###autoload +(defun diff-buffer-with-file (&optional buffer) + "View the differences between BUFFER and its associated file. +This requires the external program `diff' to be in your `exec-path'." + (interactive "bBuffer: ") + (with-current-buffer (get-buffer (or buffer (current-buffer))) + (diff buffer-file-name (current-buffer) nil 'noasync))) + +(provide 'diff) + +;;; diff.el ends here |