1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
|
;;; diff.el --- run `diff' -*- lexical-binding: t -*-
;; Copyright (C) 1992, 1994, 1996, 2001-2013 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:
(declare-function diff-setup-whitespace "diff-mode" ())
(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 optional args OLD-TEMP-FILE and/or NEW-TEMP-FILE are non-nil,
delete the temporary files so named."
(if old-temp-file (delete-file old-temp-file))
(if new-temp-file (delete-file new-temp-file))
(diff-setup-whitespace)
(goto-char (point-min))
(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 NEW, then OLD, 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 the variable `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)))
(defvar diff-use-labels 'check
"Whether `diff-command' understands the \"--label\" option.
Possible values are:
t -- yes, it does
nil -- no, it does not
check -- try to probe whether it does")
(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*")))
(when (eq 'check diff-use-labels)
(setq diff-use-labels
(with-temp-buffer
(when (ignore-errors (call-process diff-command nil t nil "--help"))
(if (search-backward "--label" nil t) t)))))
(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
(and (or old-alt new-alt)
(eq diff-use-labels t)
(list "--label"
(if (stringp old) old
(prin1-to-string old))
"--label"
(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)
(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)
(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)))
;;;###autoload
(defun diff-latest-backup-file (fn)
"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
|
