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
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
| | ;;; emacs-lock.el --- protect buffers against killing or exiting -*- lexical-binding: t -*-
;; Copyright (C) 2011-2018 Free Software Foundation, Inc.
;; Author: Juanma Barranquero <lekktu@gmail.com>
;; Inspired by emacs-lock.el by Tom Wurgler <twurgler@goodyear.com>
;; Maintainer: emacs-devel@gnu.org
;; Keywords: extensions, processes
;; 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 <https://www.gnu.org/licenses/>.
;;; Commentary:
;; This package defines a minor mode Emacs Lock to mark a buffer as
;; protected against accidental killing, or exiting Emacs, or both.
;; Buffers associated with inferior modes, like shell or telnet, can
;; be treated specially, by auto-unlocking them if their inferior
;; processes are dead.
;;; Code:
(defgroup emacs-lock nil
"Emacs-Lock mode."
:version "24.1"
:group 'convenience)
(defcustom emacs-lock-default-locking-mode 'all
"Default locking mode of Emacs-Locked buffers.
Its value is used as the default for `emacs-lock-mode' (which
see) the first time that Emacs Lock mode is turned on in a buffer
without passing an explicit locking mode.
Possible values are:
exit -- Emacs cannot exit while the buffer is locked
kill -- the buffer cannot be killed, but Emacs can exit as usual
all -- the buffer is locked against both actions
nil -- the buffer is not locked"
:type '(choice
(const :tag "Do not allow Emacs to exit" exit)
(const :tag "Do not allow killing the buffer" kill)
(const :tag "Do not allow killing the buffer or exiting Emacs" all)
(const :tag "Do not lock the buffer" nil))
:group 'emacs-lock
:version "24.1")
;; Note: as auto-unlocking can lead to data loss, it would be better
;; to default to nil; but the value below is for compatibility with
;; the old emacs-lock.el.
(defcustom emacs-lock-unlockable-modes '((shell-mode . all)
(telnet-mode . all))
"Alist of auto-unlockable modes.
Each element is a pair (MAJOR-MODE . ACTION), where ACTION is
one of `kill', `exit' or `all'. Buffers with matching major
modes are auto-unlocked for the specific action if their
inferior processes are not alive. If this variable is t, all
buffers associated to inferior processes are auto-unlockable
for both actions (NOT RECOMMENDED)."
:type '(choice
(const :tag "All buffers with inferior processes" t)
(repeat :tag "Selected modes"
(cons :tag "Set auto-unlock for"
(symbol :tag "Major mode")
(radio
(const :tag "Allow exiting" exit)
(const :tag "Allow killing" kill)
(const :tag "Allow both" all)))))
:group 'emacs-lock
:version "24.1")
(defcustom emacs-lock-locked-buffer-functions nil
"Abnormal hook run when Emacs Lock prevents exiting Emacs, or killing a buffer.
The functions get one argument, the first locked buffer found."
:type 'hook
:group 'emacs-lock
:version "24.3")
(define-obsolete-variable-alias 'emacs-lock-from-exiting
'emacs-lock-mode "24.1")
(defvar-local emacs-lock-mode nil
"If non-nil, the current buffer is locked.
It can be one of the following values:
exit -- Emacs cannot exit while the buffer is locked
kill -- the buffer cannot be killed, but Emacs can exit as usual
all -- the buffer is locked against both actions
nil -- the buffer is not locked")
(put 'emacs-lock-mode 'permanent-local t)
(defvar-local emacs-lock--old-mode nil
"Most recent locking mode set on the buffer.
Internal use only.")
(put 'emacs-lock--old-mode 'permanent-local t)
(defvar-local emacs-lock--try-unlocking nil
"Non-nil if current buffer should be checked for auto-unlocking.
Internal use only.")
(put 'emacs-lock--try-unlocking 'permanent-local t)
(defun emacs-lock-live-process-p (buffer-or-name)
"Return t if BUFFER-OR-NAME is associated with a live process."
(process-live-p (get-buffer-process buffer-or-name)))
(defun emacs-lock--can-auto-unlock (action)
"Return t if the current buffer can auto-unlock for ACTION.
ACTION must be one of `kill' or `exit'.
See `emacs-lock-unlockable-modes'."
(and emacs-lock--try-unlocking
(not (emacs-lock-live-process-p (current-buffer)))
(or (eq emacs-lock-unlockable-modes t)
(let ((unlock (cdr (assq major-mode emacs-lock-unlockable-modes))))
(or (eq unlock 'all) (eq unlock action))))))
(defun emacs-lock--exit-locked-buffer ()
"Return the first exit-locked buffer found."
(save-current-buffer
(catch :found
(dolist (buffer (buffer-list))
(set-buffer buffer)
(unless (or (emacs-lock--can-auto-unlock 'exit)
(memq emacs-lock-mode '(nil kill)))
(throw :found buffer)))
nil)))
(defun emacs-lock--kill-emacs-hook ()
"Signal an error if any buffer is exit-locked.
Used from `kill-emacs-hook' (which see)."
(let ((locked (emacs-lock--exit-locked-buffer)))
(when locked
(run-hook-with-args 'emacs-lock-locked-buffer-functions locked)
(error "Emacs cannot exit because buffer %S is locked"
(buffer-name locked)))))
(defun emacs-lock--kill-emacs-query-functions ()
"Display a message if any buffer is exit-locked.
Return a value appropriate for `kill-emacs-query-functions' (which see)."
(let ((locked (emacs-lock--exit-locked-buffer)))
(if (not locked)
t
(run-hook-with-args 'emacs-lock-locked-buffer-functions locked)
(message "Emacs cannot exit because buffer %S is locked"
(buffer-name locked))
nil)))
(defun emacs-lock--kill-buffer-query-functions ()
"Display a message if the current buffer is kill-locked.
Return a value appropriate for `kill-buffer-query-functions' (which see)."
(if (or (emacs-lock--can-auto-unlock 'kill)
(memq emacs-lock-mode '(nil exit)))
t
(run-hook-with-args 'emacs-lock-locked-buffer-functions (current-buffer))
(message "Buffer %S is locked and cannot be killed" (buffer-name))
nil))
(defun emacs-lock--set-mode (mode arg)
"Setter function for `emacs-lock-mode'."
(setq emacs-lock-mode
(cond ((memq arg '(all exit kill))
;; explicit locking mode arg, use it
arg)
((and (eq arg current-prefix-arg) (consp current-prefix-arg))
;; called with C-u M-x emacs-lock-mode, so ask the user
(intern (completing-read "Locking mode: "
'("all" "exit" "kill")
nil t nil nil
(symbol-name
emacs-lock-default-locking-mode))))
((eq mode t)
;; turn on, so use previous setting, or customized default
(or emacs-lock--old-mode emacs-lock-default-locking-mode))
(t
;; anything else (turn off)
mode))))
;;;###autoload
(define-minor-mode emacs-lock-mode
"Toggle Emacs Lock mode in the current buffer.
If called with a plain prefix argument, ask for the locking mode
to be used.
Initially, if the user does not pass an explicit locking mode, it
defaults to `emacs-lock-default-locking-mode' (which see);
afterwards, the locking mode most recently set on the buffer is
used instead.
When called from Elisp code, ARG can be any locking mode:
exit -- Emacs cannot exit while the buffer is locked
kill -- the buffer cannot be killed, but Emacs can exit as usual
all -- the buffer is locked against both actions
Other values are interpreted as usual."
:init-value nil
:lighter (""
(emacs-lock--try-unlocking " locked:" " Locked:")
(:eval (symbol-name emacs-lock-mode)))
:group 'emacs-lock
:variable (emacs-lock-mode .
(lambda (mode)
(emacs-lock--set-mode mode arg)))
(when emacs-lock-mode
(setq emacs-lock--old-mode emacs-lock-mode)
(setq emacs-lock--try-unlocking
(and (if (eq emacs-lock-unlockable-modes t)
(emacs-lock-live-process-p (current-buffer))
(assq major-mode emacs-lock-unlockable-modes))
t))))
(unless noninteractive
(add-hook 'kill-buffer-query-functions 'emacs-lock--kill-buffer-query-functions)
;; We set a hook in both kill-emacs-hook and kill-emacs-query-functions because
;; we really want to use k-e-q-f to stop as soon as possible, but don't want to
;; be caught by surprise if someone calls `kill-emacs' instead.
(add-hook 'kill-emacs-hook 'emacs-lock--kill-emacs-hook)
(add-hook 'kill-emacs-query-functions 'emacs-lock--kill-emacs-query-functions))
(defun emacs-lock-unload-function ()
"Unload the Emacs Lock library."
(catch :continue
(dolist (buffer (buffer-list))
(set-buffer buffer)
(when emacs-lock-mode
(if (y-or-n-p (format "Buffer %S is locked, unlock it? " (buffer-name)))
(emacs-lock-mode -1)
(message "Unloading of feature `emacs-lock' aborted.")
(throw :continue t))))
;; continue standard unloading
nil))
;;; Compatibility
(defun toggle-emacs-lock ()
"Toggle `emacs-lock-from-exiting' for the current buffer."
(declare (obsolete emacs-lock-mode "24.1"))
(interactive)
(call-interactively 'emacs-lock-mode))
(provide 'emacs-lock)
;;; emacs-lock.el ends here
|