| 1 | ;;; diff.el --- run `diff' in compilation-mode |
| 2 | |
| 3 | ;; Copyright (C) 1992, 1994, 1996, 2001, 2002, 2003, 2004, 2005, 2006, |
| 4 | ;; 2007, 2008, 2009 Free Software Foundation, Inc. |
| 5 | |
| 6 | ;; Author: Frank Bresz |
| 7 | ;; (according to authors.el) |
| 8 | ;; Maintainer: FSF |
| 9 | ;; Keywords: unix, tools |
| 10 | |
| 11 | ;; This file is part of GNU Emacs. |
| 12 | |
| 13 | ;; GNU Emacs is free software: you can redistribute it and/or modify |
| 14 | ;; it under the terms of the GNU General Public License as published by |
| 15 | ;; the Free Software Foundation, either version 3 of the License, or |
| 16 | ;; (at your option) any later version. |
| 17 | |
| 18 | ;; GNU Emacs is distributed in the hope that it will be useful, |
| 19 | ;; but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 20 | ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 21 | ;; GNU General Public License for more details. |
| 22 | |
| 23 | ;; You should have received a copy of the GNU General Public License |
| 24 | ;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. |
| 25 | |
| 26 | ;;; Commentary: |
| 27 | |
| 28 | ;; This package helps you explore differences between files, using the |
| 29 | ;; UNIX command diff(1). The commands are `diff' and `diff-backup'. |
| 30 | ;; You can specify options with `diff-switches'. |
| 31 | |
| 32 | ;;; Code: |
| 33 | |
| 34 | (defgroup diff nil |
| 35 | "Comparing files with `diff'." |
| 36 | :group 'tools) |
| 37 | |
| 38 | ;;;###autoload |
| 39 | (defcustom diff-switches "-c" |
| 40 | "A string or list of strings specifying switches to be passed to diff." |
| 41 | :type '(choice string (repeat string)) |
| 42 | :group 'diff) |
| 43 | |
| 44 | ;;;###autoload |
| 45 | (defcustom diff-command "diff" |
| 46 | "The command to use to run diff." |
| 47 | :type 'string |
| 48 | :group 'diff) |
| 49 | |
| 50 | (defvar diff-old-temp-file nil |
| 51 | "This is the name of a temp file to be deleted after diff finishes.") |
| 52 | (defvar diff-new-temp-file nil |
| 53 | "This is the name of a temp file to be deleted after diff finishes.") |
| 54 | |
| 55 | ;; prompt if prefix arg present |
| 56 | (defun diff-switches () |
| 57 | (if current-prefix-arg |
| 58 | (read-string "Diff switches: " |
| 59 | (if (stringp diff-switches) |
| 60 | diff-switches |
| 61 | (mapconcat 'identity diff-switches " "))))) |
| 62 | |
| 63 | (defun diff-sentinel (code) |
| 64 | "Code run when the diff process exits. |
| 65 | CODE is the exit code of the process. It should be 0 only if no diffs |
| 66 | were found." |
| 67 | (if diff-old-temp-file (delete-file diff-old-temp-file)) |
| 68 | (if diff-new-temp-file (delete-file diff-new-temp-file)) |
| 69 | (save-excursion |
| 70 | (goto-char (point-max)) |
| 71 | (let ((inhibit-read-only t)) |
| 72 | (insert (format "\nDiff finished%s. %s\n" |
| 73 | (cond ((equal 0 code) " (no differences)") |
| 74 | ((equal 2 code) " (diff error)") |
| 75 | (t "")) |
| 76 | (current-time-string)))))) |
| 77 | |
| 78 | (defvar diff-old-file nil) |
| 79 | (defvar diff-new-file nil) |
| 80 | (defvar diff-extra-args nil) |
| 81 | |
| 82 | ;;;###autoload |
| 83 | (defun diff (old new &optional switches no-async) |
| 84 | "Find and display the differences between OLD and NEW files. |
| 85 | When called interactively, read OLD and NEW using the minibuffer; |
| 86 | the default for NEW is the current buffer's file name, and the |
| 87 | default for OLD is a backup file for NEW, if one exists. |
| 88 | If NO-ASYNC is non-nil, call diff synchronously. |
| 89 | |
| 90 | When called interactively with a prefix argument, prompt |
| 91 | interactively for diff switches. Otherwise, the switches |
| 92 | specified in `diff-switches' are passed to the diff command." |
| 93 | (interactive |
| 94 | (let (oldf newf) |
| 95 | (setq newf (buffer-file-name) |
| 96 | newf (if (and newf (file-exists-p newf)) |
| 97 | (read-file-name |
| 98 | (concat "Diff new file (default " |
| 99 | (file-name-nondirectory newf) "): ") |
| 100 | nil newf t) |
| 101 | (read-file-name "Diff new file: " nil nil t))) |
| 102 | (setq oldf (file-newest-backup newf) |
| 103 | oldf (if (and oldf (file-exists-p oldf)) |
| 104 | (read-file-name |
| 105 | (concat "Diff original file (default " |
| 106 | (file-name-nondirectory oldf) "): ") |
| 107 | (file-name-directory oldf) oldf t) |
| 108 | (read-file-name "Diff original file: " |
| 109 | (file-name-directory newf) nil t))) |
| 110 | (list oldf newf (diff-switches)))) |
| 111 | (setq new (expand-file-name new) |
| 112 | old (expand-file-name old)) |
| 113 | (or switches (setq switches diff-switches)) ; If not specified, use default. |
| 114 | (let* ((old-alt (file-local-copy old)) |
| 115 | (new-alt (file-local-copy new)) |
| 116 | (command |
| 117 | (mapconcat 'identity |
| 118 | `(,diff-command |
| 119 | ;; Use explicitly specified switches |
| 120 | ,@(if (listp switches) switches (list switches)) |
| 121 | ,@(if (or old-alt new-alt) |
| 122 | (list "-L" old "-L" new)) |
| 123 | ,(shell-quote-argument (or old-alt old)) |
| 124 | ,(shell-quote-argument (or new-alt new))) |
| 125 | " ")) |
| 126 | (buf (get-buffer-create "*Diff*")) |
| 127 | (thisdir default-directory) |
| 128 | proc) |
| 129 | (save-excursion |
| 130 | (display-buffer buf) |
| 131 | (set-buffer buf) |
| 132 | (setq buffer-read-only nil) |
| 133 | (buffer-disable-undo (current-buffer)) |
| 134 | (let ((inhibit-read-only t)) |
| 135 | (erase-buffer)) |
| 136 | (buffer-enable-undo (current-buffer)) |
| 137 | (diff-mode) |
| 138 | ;; Use below 2 vars for backward-compatibility. |
| 139 | (set (make-local-variable 'diff-old-file) old) |
| 140 | (set (make-local-variable 'diff-new-file) new) |
| 141 | (set (make-local-variable 'diff-extra-args) (list switches no-async)) |
| 142 | (set (make-local-variable 'revert-buffer-function) |
| 143 | (lambda (ignore-auto noconfirm) |
| 144 | (apply 'diff diff-old-file diff-new-file diff-extra-args))) |
| 145 | (set (make-local-variable 'diff-old-temp-file) old-alt) |
| 146 | (set (make-local-variable 'diff-new-temp-file) new-alt) |
| 147 | (setq default-directory thisdir) |
| 148 | (let ((inhibit-read-only t)) |
| 149 | (insert command "\n")) |
| 150 | (if (and (not no-async) (fboundp 'start-process)) |
| 151 | (progn |
| 152 | (setq proc (start-process "Diff" buf shell-file-name |
| 153 | shell-command-switch command)) |
| 154 | (set-process-filter proc 'diff-process-filter) |
| 155 | (set-process-sentinel |
| 156 | proc (lambda (proc msg) |
| 157 | (with-current-buffer (process-buffer proc) |
| 158 | (diff-sentinel (process-exit-status proc)))))) |
| 159 | ;; Async processes aren't available. |
| 160 | (let ((inhibit-read-only t)) |
| 161 | (diff-sentinel |
| 162 | (call-process shell-file-name nil buf nil |
| 163 | shell-command-switch command))))) |
| 164 | buf)) |
| 165 | |
| 166 | (defun diff-process-filter (proc string) |
| 167 | (with-current-buffer (process-buffer proc) |
| 168 | (let ((moving (= (point) (process-mark proc)))) |
| 169 | (save-excursion |
| 170 | ;; Insert the text, advancing the process marker. |
| 171 | (goto-char (process-mark proc)) |
| 172 | (let ((inhibit-read-only t)) |
| 173 | (insert string)) |
| 174 | (set-marker (process-mark proc) (point))) |
| 175 | (if moving (goto-char (process-mark proc)))))) |
| 176 | |
| 177 | ;;;###autoload |
| 178 | (defun diff-backup (file &optional switches) |
| 179 | "Diff this file with its backup file or vice versa. |
| 180 | Uses the latest backup, if there are several numerical backups. |
| 181 | If this file is a backup, diff it with its original. |
| 182 | The backup file is the first file given to `diff'. |
| 183 | With prefix arg, prompt for diff switches." |
| 184 | (interactive (list (read-file-name "Diff (file with backup): ") |
| 185 | (diff-switches))) |
| 186 | (let (bak ori) |
| 187 | (if (backup-file-name-p file) |
| 188 | (setq bak file |
| 189 | ori (file-name-sans-versions file)) |
| 190 | (setq bak (or (diff-latest-backup-file file) |
| 191 | (error "No backup found for %s" file)) |
| 192 | ori file)) |
| 193 | (diff bak ori switches))) |
| 194 | |
| 195 | (defun diff-latest-backup-file (fn) ; actually belongs into files.el |
| 196 | "Return the latest existing backup of FILE, or nil." |
| 197 | (let ((handler (find-file-name-handler fn 'diff-latest-backup-file))) |
| 198 | (if handler |
| 199 | (funcall handler 'diff-latest-backup-file fn) |
| 200 | (file-newest-backup fn)))) |
| 201 | |
| 202 | (provide 'diff) |
| 203 | |
| 204 | ;; arch-tag: 7de2c29b-7ea5-4b85-9b9d-72dd860de2bd |
| 205 | ;;; diff.el ends here |