server.el 51.2 KB
Newer Older
1
;;; server.el --- Lisp code for GNU Emacs running as server process
Eric S. Raymond's avatar
Eric S. Raymond committed
2

3
;; Copyright (C) 1986, 1987, 1992, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
4
;;   2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008 Free Software Foundation, Inc.
Eric S. Raymond's avatar
Eric S. Raymond committed
5

Eric S. Raymond's avatar
Eric S. Raymond committed
6
;; Author: William Sommerfeld <wesommer@athena.mit.edu>
Richard M. Stallman's avatar
Richard M. Stallman committed
7
;; Maintainer: FSF
Eric S. Raymond's avatar
Eric S. Raymond committed
8
;; Keywords: processes
Eric S. Raymond's avatar
Eric S. Raymond committed
9

root's avatar
root committed
10
;; Changes by peck@sun.com and by rms.
11
;; Overhaul by Karoly Lorentey <lorentey@elte.hu> for multi-tty support.
root's avatar
root committed
12 13 14

;; This file is part of GNU Emacs.

15
;; GNU Emacs is free software: you can redistribute it and/or modify
root's avatar
root committed
16
;; it under the terms of the GNU General Public License as published by
17 18
;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.
root's avatar
root committed
19 20 21 22 23 24 25

;; 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
26
;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
root's avatar
root committed
27

Eric S. Raymond's avatar
Eric S. Raymond committed
28
;;; Commentary:
root's avatar
root committed
29

Erik Naggum's avatar
Erik Naggum committed
30 31
;; This Lisp code is run in Emacs when it is to operate as
;; a server for other processes.
root's avatar
root committed
32

Erik Naggum's avatar
Erik Naggum committed
33
;; Load this library and do M-x server-edit to enable Emacs as a server.
34 35 36
;; Emacs opens up a socket for communication with clients.  If there are no
;; client buffers to edit, server-edit acts like (switch-to-buffer
;; (other-buffer))
root's avatar
root committed
37

Erik Naggum's avatar
Erik Naggum committed
38 39 40 41
;; When some other program runs "the editor" to edit a file,
;; "the editor" can be the Emacs client program ../lib-src/emacsclient.
;; This program transmits the file names to Emacs through
;; the server subprocess, and Emacs visits them and lets you edit them.
root's avatar
root committed
42

Karoly Lorentey's avatar
Karoly Lorentey committed
43
;; Note that any number of clients may dispatch files to Emacs to be edited.
root's avatar
root committed
44

Erik Naggum's avatar
Erik Naggum committed
45
;; When you finish editing a Server buffer, again call server-edit
46 47
;; to mark that buffer as done for the client and switch to the next
;; Server buffer.  When all the buffers for a client have been edited
Erik Naggum's avatar
Erik Naggum committed
48
;; and exited with server-edit, the client "editor" will return
49
;; to the program that invoked it.
root's avatar
root committed
50

Erik Naggum's avatar
Erik Naggum committed
51 52 53 54
;; Your editing commands and Emacs's display output go to and from
;; the terminal in the usual way.  Thus, server operation is possible
;; only when Emacs can talk to the terminal at the time you invoke
;; the client.  This is possible in four cases:
root's avatar
root committed
55

Erik Naggum's avatar
Erik Naggum committed
56 57
;; 1. On a window system, where Emacs runs in one window and the
;; program that wants to use "the editor" runs in another.
root's avatar
root committed
58

Erik Naggum's avatar
Erik Naggum committed
59 60
;; 2. On a multi-terminal system, where Emacs runs on one terminal and the
;; program that wants to use "the editor" runs on another.
root's avatar
root committed
61

Erik Naggum's avatar
Erik Naggum committed
62 63
;; 3. When the program that wants to use "the editor" is running
;; as a subprocess of Emacs.
root's avatar
root committed
64

Erik Naggum's avatar
Erik Naggum committed
65 66 67 68 69
;; 4. On a system with job control, when Emacs is suspended, the program
;; that wants to use "the editor" will stop and display
;; "Waiting for Emacs...".  It can then be suspended, and Emacs can be
;; brought into the foreground for editing.  When done editing, Emacs is
;; suspended again, and the client program is brought into the foreground.
root's avatar
root committed
70

71 72
;; The buffer local variable "server-buffer-clients" lists
;; the clients who are waiting for this buffer to be edited.
Erik Naggum's avatar
Erik Naggum committed
73 74
;; The global variable "server-clients" lists all the waiting clients,
;; and which files are yet to be edited for each.
Eric S. Raymond's avatar
Eric S. Raymond committed
75

Stefan Monnier's avatar
Stefan Monnier committed
76 77 78 79 80 81 82
;; Todo:

;; - handle command-line-args-left.
;; - move most of the args processing and decision making from emacsclient.c
;;   to here.
;; - fix up handling of the client's environment (place it in the terminal?).

Eric S. Raymond's avatar
Eric S. Raymond committed
83
;;; Code:
84 85 86

(eval-when-compile (require 'cl))

Richard M. Stallman's avatar
Richard M. Stallman committed
87 88 89 90
(defgroup server nil
  "Emacs running as a server process."
  :group 'external)

91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113
(defcustom server-use-tcp nil
  "If non-nil, use TCP sockets instead of local sockets."
  :set #'(lambda (sym val)
           (unless (featurep 'make-network-process '(:family local))
             (setq val t)
             (unless load-in-progress
               (message "Local sockets unsupported, using TCP sockets")))
           (when val (random t))
           (set-default sym val))
  :group 'server
  :type 'boolean
  :version "22.1")

(defcustom server-host nil
  "The name or IP address to use as host address of the server process.
If set, the server accepts remote connections; otherwise it is local."
  :group 'server
  :type '(choice
          (string :tag "Name or IP address")
          (const :tag "Local" nil))
  :version "22.1")
(put 'server-host 'risky-local-variable t)

114
(defcustom server-auth-dir (locate-user-emacs-file "server/")
115 116 117 118 119 120
  "Directory for server authentication files."
  :group 'server
  :type 'directory
  :version "22.1")
(put 'server-auth-dir 'risky-local-variable t)

121
(defcustom server-raise-frame t
122
  "If non-nil, raise frame when switching to a buffer."
123 124 125 126
  :group 'server
  :type 'boolean
  :version "22.1")

Richard M. Stallman's avatar
Richard M. Stallman committed
127
(defcustom server-visit-hook nil
128
  "Hook run when visiting a file for the Emacs server."
Richard M. Stallman's avatar
Richard M. Stallman committed
129
  :group 'server
130
  :type 'hook)
Richard M. Stallman's avatar
Richard M. Stallman committed
131 132

(defcustom server-switch-hook nil
133
  "Hook run when switching to a buffer for the Emacs server."
Richard M. Stallman's avatar
Richard M. Stallman committed
134
  :group 'server
135
  :type 'hook)
Richard M. Stallman's avatar
Richard M. Stallman committed
136 137

(defcustom server-done-hook nil
138
  "Hook run when done editing a buffer for the Emacs server."
Richard M. Stallman's avatar
Richard M. Stallman committed
139
  :group 'server
140
  :type 'hook)
141

142 143
(defvar server-process nil
  "The current server process.")
root's avatar
root committed
144 145 146

(defvar server-clients nil
  "List of current server clients.
147
Each element is a process.")
Karoly Lorentey's avatar
Karoly Lorentey committed
148

root's avatar
root committed
149
(defvar server-buffer-clients nil
150
  "List of client processes requesting editing of current buffer.")
151
(make-variable-buffer-local 'server-buffer-clients)
root's avatar
root committed
152 153 154
;; Changing major modes should not erase this local.
(put 'server-buffer-clients 'permanent-local t)

Dave Love's avatar
Dave Love committed
155
(defcustom server-window nil
156
  "Specification of the window to use for selecting Emacs server buffers.
157
If nil, use the selected window.
158
If it is a function, it should take one argument (a buffer) and
Dave Love's avatar
Dave Love committed
159 160 161 162 163 164 165
display and select it.  A common value is `pop-to-buffer'.
If it is a window, use that.
If it is a frame, use the frame's selected window.

It is not meaningful to set this to a specific frame or window with Custom.
Only programs can do so."
  :group 'server
166
  :version "22.1"
Dave Love's avatar
Dave Love committed
167 168 169 170
  :type '(choice (const :tag "Use selected window"
			:match (lambda (widget value)
				 (not (functionp value)))
			nil)
171
		 (function-item :tag "Display in new frame" switch-to-buffer-other-frame)
Dave Love's avatar
Dave Love committed
172 173
		 (function-item :tag "Use pop-to-buffer" pop-to-buffer)
		 (function :tag "Other function")))
174

Richard M. Stallman's avatar
Richard M. Stallman committed
175
(defcustom server-temp-file-regexp "^/tmp/Re\\|/draft$"
176
  "Regexp matching names of temporary files.
Dave Love's avatar
Dave Love committed
177 178
These are deleted and reused after each edit by the programs that
invoke the Emacs server."
Richard M. Stallman's avatar
Richard M. Stallman committed
179 180
  :group 'server
  :type 'regexp)
root's avatar
root committed
181

182
(defcustom server-kill-new-buffers t
183
  "Whether to kill buffers when done with them.
184
If non-nil, kill a buffer unless it already existed before editing
185
it with the Emacs server.  If nil, kill only buffers as specified by
186
`server-temp-file-regexp'.
187 188
Please note that only buffers that still have a client are killed,
i.e. buffers visited with \"emacsclient --no-wait\" are never killed in
189 190 191 192 193
this way."
  :group 'server
  :type 'boolean
  :version "21.1")

root's avatar
root committed
194
(or (assq 'server-buffer-clients minor-mode-alist)
195
    (push '(server-buffer-clients " Server") minor-mode-alist))
root's avatar
root committed
196

197
(defvar server-existing-buffer nil
198
  "Non-nil means the buffer existed before the server was asked to visit it.
199
This means that the server should not kill the buffer when you say you
200
are done with it in the server.")
201 202
(make-variable-buffer-local 'server-existing-buffer)

Stefan Monnier's avatar
Stefan Monnier committed
203 204
(defvar server-name "server")

205 206
(defvar server-socket-dir
  (format "%s/emacs%d" (or (getenv "TMPDIR") "/tmp") (user-uid))
207
  "The directory in which to place the server socket.")
208

Karoly Lorentey's avatar
Karoly Lorentey committed
209 210 211
(defun server-clients-with (property value)
  "Return a list of clients with PROPERTY set to VALUE."
  (let (result)
212 213 214
    (dolist (proc server-clients result)
      (when (equal value (process-get proc property))
	(push proc result)))))
Karoly Lorentey's avatar
Karoly Lorentey committed
215 216 217 218

(defun server-add-client (proc)
  "Create a client for process PROC, if it doesn't already have one.
New clients have no properties."
219
  (add-to-list 'server-clients proc))
Karoly Lorentey's avatar
Karoly Lorentey committed
220

221 222
(defmacro server-with-environment (env vars &rest body)
  "Evaluate BODY with environment variables VARS set to those in ENV.
223 224
The environment variables are then restored to their previous values.

225 226
VARS should be a list of strings.
ENV should be in the same format as `process-environment'."
227
  (declare (indent 2))
228 229 230
  (let ((var (make-symbol "var"))
	(value (make-symbol "value")))
    `(let ((process-environment process-environment))
231
       (dolist (,var ,vars)
232
         (let ((,value (getenv-internal ,var ,env)))
233 234 235 236 237
           (push (if (null ,value)
                     ,var
                   (concat ,var "=" ,value))
                 process-environment)))
       (progn ,@body))))
238

239
(defun server-delete-client (proc &optional noframe)
240
  "Delete PROC, including its buffers, terminals and frames.
241
If NOFRAME is non-nil, let the frames live.  (To be used from
242
`delete-frame-functions'.)"
243
  (server-log (concat "server-delete-client" (if noframe " noframe")) proc)
Karoly Lorentey's avatar
Karoly Lorentey committed
244
  ;; Force a new lookup of client (prevents infinite recursion).
245 246
  (when (memq proc server-clients)
    (let ((buffers (process-get proc 'buffers)))
Karoly Lorentey's avatar
Karoly Lorentey committed
247

248
      ;; Kill the client's buffers.
Karoly Lorentey's avatar
Karoly Lorentey committed
249
      (dolist (buf buffers)
250 251 252
	(when (buffer-live-p buf)
	  (with-current-buffer buf
	    ;; Kill the buffer if necessary.
253 254
	    (when (and (equal server-buffer-clients
			      (list proc))
255 256
		       (or (and server-kill-new-buffers
				(not server-existing-buffer))
257 258 259 260 261 262 263 264 265 266
			   (server-temp-file-p))
		       (not (buffer-modified-p)))
	      (let (flag)
		(unwind-protect
		    (progn (setq server-buffer-clients nil)
			   (kill-buffer (current-buffer))
			   (setq flag t))
		  (unless flag
		    ;; Restore clients if user pressed C-g in `kill-buffer'.
		    (setq server-buffer-clients (list proc)))))))))
Karoly Lorentey's avatar
Karoly Lorentey committed
267

268 269 270 271 272 273 274 275 276 277
      ;; Delete the client's frames.
      (unless noframe
	(dolist (frame (frame-list))
	  (when (and (frame-live-p frame)
		     (equal proc (frame-parameter frame 'client)))
	    ;; Prevent `server-handle-delete-frame' from calling us
	    ;; recursively.
	    (set-frame-parameter frame 'client nil)
	    (delete-frame frame))))

278
      (setq server-clients (delq proc server-clients))
279

Karoly Lorentey's avatar
Karoly Lorentey committed
280
      ;; Delete the client's tty.
281
      (let ((terminal (process-get proc 'terminal)))
282 283
	;; Only delete the terminal if it is non-nil.
	(when (and terminal (eq (terminal-live-p terminal) t))
284
	  (delete-terminal terminal)))
Karoly Lorentey's avatar
Karoly Lorentey committed
285 286

      ;; Delete the client's process.
287 288
      (if (eq (process-status proc) 'open)
	  (delete-process proc))
Karoly Lorentey's avatar
Karoly Lorentey committed
289 290 291

      (server-log "Deleted" proc))))

292
(defvar server-log-time-function 'current-time-string
293
  "Function to generate timestamps for `server-buffer'.")
294

Stefan Monnier's avatar
Stefan Monnier committed
295 296 297 298
(defconst server-buffer " *server*"
  "Buffer used internally by Emacs's server.
One use is to log the I/O for debugging purposes (see `server-log'),
the other is to provide a current buffer in which the process filter can
299
safely let-bind buffer-local variables like `default-directory'.")
Stefan Monnier's avatar
Stefan Monnier committed
300 301 302 303

(defvar server-log nil
  "If non-nil, log the server's inputs and outputs in the `server-buffer'.")

304
(defun server-log (string &optional client)
Stefan Monnier's avatar
Stefan Monnier committed
305
  "If `server-log' is non-nil, log STRING to `server-buffer'.
306
If CLIENT is non-nil, add a description of it to the logged message."
Stefan Monnier's avatar
Stefan Monnier committed
307 308
  (when server-log
    (with-current-buffer (get-buffer-create server-buffer)
309
      (goto-char (point-max))
310
      (insert (funcall server-log-time-function)
311
	      (cond
312 313 314
		((null client) " ")
		((listp client) (format " %s: " (car client)))
		(t (format " %s: " client)))
315 316
	      string)
      (or (bolp) (newline)))))
root's avatar
root committed
317 318

(defun server-sentinel (proc msg)
Karoly Lorentey's avatar
Karoly Lorentey committed
319
  "The process sentinel for Emacs server connections."
320 321 322 323 324
  ;; If this is a new client process, set the query-on-exit flag to nil
  ;; for this process (it isn't inherited from the server process).
  (when (and (eq (process-status proc) 'open)
	     (process-query-on-exit-flag proc))
    (set-process-query-on-exit-flag proc nil))
325 326 327 328 329 330
  ;; Delete the associated connection file, if applicable.
  ;; This is actually problematic: the file may have been overwritten by
  ;; another Emacs server in the mean time, so it's not ours any more.
  ;; (and (process-contact proc :server)
  ;;      (eq (process-status proc) 'closed)
  ;;      (ignore-errors (delete-file (process-get proc :server-file))))
Karoly Lorentey's avatar
Karoly Lorentey committed
331 332
  (server-log (format "Status changed to %s: %s" (process-status proc) msg) proc)
  (server-delete-client proc))
333

334 335
(defun server-select-display (display)
  ;; If the current frame is on `display' we're all set.
336 337 338 339
  ;; Similarly if we are unable to open a frames on other displays, there's
  ;; nothing more we can do.
  (unless (or (not (fboundp 'make-frame-on-display))
              (equal (frame-parameter (selected-frame) 'display) display))
340 341 342 343 344 345 346 347 348 349 350
    ;; Otherwise, look for an existing frame there and select it.
    (dolist (frame (frame-list))
      (when (equal (frame-parameter frame 'display) display)
	(select-frame frame)))
    ;; If there's no frame on that display yet, create and select one.
    (unless (equal (frame-parameter (selected-frame) 'display) display)
      (let* ((buffer (generate-new-buffer " *server-dummy*"))
             (frame (make-frame-on-display
                     display
                     ;; Make it display (and remember) some dummy buffer, so
                     ;; we can detect later if the frame is in use or not.
351
                     `((server-dummy-buffer . ,buffer)
352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376
                       ;; This frame may be deleted later (see
                       ;; server-unselect-display) so we want it to be as
                       ;; unobtrusive as possible.
                       (visibility . nil)))))
        (select-frame frame)
        (set-window-buffer (selected-window) buffer)
        frame))))

(defun server-unselect-display (frame)
  (when (frame-live-p frame)
    ;; If the temporary frame is in use (displays something real), make it
    ;; visible.  If not (which can happen if the user's customizations call
    ;; pop-to-buffer etc.), delete it to avoid preserving the connection after
    ;; the last real frame is deleted.
    (if (and (eq (frame-first-window frame)
                 (next-window (frame-first-window frame) 'nomini))
             (eq (window-buffer (frame-first-window frame))
                 (frame-parameter frame 'server-dummy-buffer)))
        ;; The temp frame still only shows one buffer, and that is the
        ;; internal temp buffer.
        (delete-frame frame)
      (set-frame-parameter frame 'visibility t))
    (kill-buffer (frame-parameter frame 'server-dummy-buffer))
    (set-frame-parameter frame 'server-dummy-buffer nil)))

377 378
(defun server-handle-delete-frame (frame)
  "Delete the client connection when the emacsclient frame is deleted."
Karoly Lorentey's avatar
Karoly Lorentey committed
379
  (let ((proc (frame-parameter frame 'client)))
380 381
    (when (and (frame-live-p frame)
	       proc
382
	       ;; See if this is the last frame for this client.
383
	       (>= 1 (let ((frame-num 0))
384
		      (dolist (f (frame-list))
385 386 387
			(when (eq proc (frame-parameter f 'client))
			  (setq frame-num (1+ frame-num))))
		      frame-num)))
Karoly Lorentey's avatar
Karoly Lorentey committed
388
      (server-log (format "server-handle-delete-frame, frame %s" frame) proc)
389
      (server-delete-client proc 'noframe)))) ; Let delete-frame delete the frame later.
Karoly Lorentey's avatar
Karoly Lorentey committed
390

391
(defun server-handle-suspend-tty (terminal)
Karoly Lorentey's avatar
Karoly Lorentey committed
392
  "Notify the emacsclient process to suspend itself when its tty device is suspended."
393 394
  (dolist (proc (server-clients-with 'terminal terminal))
    (server-log (format "server-handle-suspend-tty, terminal %s" terminal) proc)
Karoly Lorentey's avatar
Karoly Lorentey committed
395
    (condition-case err
396
	(server-send-string proc "-suspend \n")
397 398
      (file-error                       ;The pipe/socket was closed.
       (ignore-errors (server-delete-client proc))))))
399

400
(defun server-unquote-arg (arg)
401 402
  "Remove &-quotation from ARG.
See `server-quote-arg' and `server-process-filter'."
403 404 405 406 407 408 409 410
  (replace-regexp-in-string
   "&." (lambda (s)
	  (case (aref s 1)
	    (?& "&")
	    (?- "-")
	    (?n "\n")
	    (t " ")))
   arg t t))
root's avatar
root committed
411

412
(defun server-quote-arg (arg)
Karoly Lorentey's avatar
Karoly Lorentey committed
413
  "In ARG, insert a & before each &, each space, each newline, and -.
414
Change spaces to underscores, too, so that the return value never
415 416 417
contains a space.

See `server-unquote-arg' and `server-process-filter'."
418 419 420 421 422 423 424 425 426
  (replace-regexp-in-string
   "[-&\n ]" (lambda (s)
	       (case (aref s 0)
		 (?& "&&")
		 (?- "&-")
		 (?\n "&n")
		 (?\s "&_")))
   arg t t))

427 428 429 430 431
(defun server-send-string (proc string)
  "A wrapper around `proc-send-string' for logging."
  (server-log (concat "Sent " string) proc)
  (process-send-string proc string))

432 433 434 435 436 437 438 439 440
(defun server-ensure-safe-dir (dir)
  "Make sure DIR is a directory with no race-condition issues.
Creates the directory if necessary and makes sure:
- there's no symlink involved
- it's owned by us
- it's not readable/writable by anybody else."
  (setq dir (directory-file-name dir))
  (let ((attrs (file-attributes dir)))
    (unless attrs
441
      (letf (((default-file-modes) ?\700)) (make-directory dir t))
442 443
      (setq attrs (file-attributes dir)))
    ;; Check that it's safe for use.
444
    (unless (and (eq t (car attrs)) (eql (nth 2 attrs) (user-uid))
445 446
                 (or (eq system-type 'windows-nt)
                     (zerop (logand ?\077 (file-modes dir)))))
447 448
      (error "The directory %s is unsafe" dir))))

Roland McGrath's avatar
Roland McGrath committed
449
;;;###autoload
root's avatar
root committed
450 451 452
(defun server-start (&optional leave-dead)
  "Allow this Emacs process to be a server for client processes.
This starts a server communications subprocess through which
Karoly Lorentey's avatar
Karoly Lorentey committed
453 454
client \"editors\" can send your editing commands to this Emacs
job.  To use the server, set up the program `emacsclient' in the
root's avatar
root committed
455 456
Emacs distribution as your standard \"editor\".

457 458
Optional argument LEAVE-DEAD (interactively, a prefix arg) means just
kill any existing server communications subprocess."
root's avatar
root committed
459
  (interactive "P")
460 461 462 463
  (when (or
	 (not server-clients)
	 (yes-or-no-p
	  "The current server still has clients; delete them? "))
464 465 466
    (when server-process
      ;; kill it dead!
      (ignore-errors (delete-process server-process)))
467 468 469 470 471 472 473
    ;; Delete the socket files made by previous server invocations.
    (condition-case ()
	(delete-file (expand-file-name server-name server-socket-dir))
      (error nil))
    ;; If this Emacs already had a server, clear out associated status.
    (while server-clients
      (server-delete-client (car server-clients)))
Karoly Lorentey's avatar
Karoly Lorentey committed
474
    ;; Now any previous server is properly stopped.
475 476 477 478
    (if leave-dead
	(progn
	  (server-log (message "Server stopped"))
	  (setq server-process nil))
479 480 481 482 483 484 485 486 487
      (let* ((server-dir (if server-use-tcp server-auth-dir server-socket-dir))
	     (server-file (expand-file-name server-name server-dir)))
	;; Make sure there is a safe directory in which to place the socket.
	(server-ensure-safe-dir server-dir)
	;; Remove any leftover socket or authentication file.
	(ignore-errors (delete-file server-file))
	(when server-process
	  (server-log (message "Restarting server")))
	(letf (((default-file-modes) ?\700))
488
	  (add-hook 'suspend-tty-functions 'server-handle-suspend-tty)
489 490 491
	  (add-hook 'delete-frame-functions 'server-handle-delete-frame)
	  (add-hook 'kill-buffer-query-functions 'server-kill-buffer-query-function)
	  (add-hook 'kill-emacs-query-functions 'server-kill-emacs-query-function)
492
	  (add-hook 'kill-emacs-hook (lambda () (server-mode -1))) ;Cleanup upon exit.
493 494 495 496 497 498 499 500 501
	  (setq server-process
		(apply #'make-network-process
		       :name server-name
		       :server t
		       :noquery t
		       :sentinel 'server-sentinel
		       :filter 'server-process-filter
		       ;; We must receive file names without being decoded.
		       ;; Those are decoded by server-process-filter according
502 503 504
		       ;; to file-name-coding-system.  Also don't get
		       ;; confused by CRs since we don't quote them.
		       :coding 'raw-text-unix
Stefan Monnier's avatar
Stefan Monnier committed
505
		       ;; The other args depend on the kind of socket used.
506 507 508 509 510 511 512 513 514 515 516 517
		       (if server-use-tcp
			   (list :family nil
				 :service t
				 :host (or server-host 'local)
				 :plist '(:authenticated nil))
			 (list :family 'local
			       :service server-file
			       :plist '(:authenticated t)))))
	  (unless server-process (error "Could not start server process"))
	  (when server-use-tcp
	    (let ((auth-key
		   (loop
Juanma Barranquero's avatar
Juanma Barranquero committed
518 519 520 521 522
		      ;; The auth key is a 64-byte string of random chars in the
		      ;; range `!'..`~'.
		      for i below 64
		      collect (+ 33 (random 94)) into auth
		      finally return (concat auth))))
523 524 525 526 527 528 529 530
	      (process-put server-process :auth-key auth-key)
	      (with-temp-file server-file
		(set-buffer-multibyte nil)
		(setq buffer-file-coding-system 'no-conversion)
		(insert (format-network-address
			 (process-contact server-process :local))
			" " (int-to-string (emacs-pid))
			"\n" auth-key)))))))))
Dave Love's avatar
Dave Love committed
531

532 533 534 535 536 537 538 539 540 541 542 543 544 545 546
(defun server-running-p (&optional name)
  "Test whether server NAME is running."
  (interactive
   (list (if current-prefix-arg
	     (read-string "Server name: " nil nil server-name))))
  (unless name (setq name server-name))
  (condition-case nil
      (progn
	(delete-process
	 (make-network-process
	  :name "server-client-test" :family 'local :server nil :noquery t
	  :service (expand-file-name name server-socket-dir)))
	t)
    (file-error nil)))

Dave Love's avatar
Dave Love committed
547 548 549 550 551 552 553 554
;;;###autoload
(define-minor-mode server-mode
  "Toggle Server mode.
With ARG, turn Server mode on if ARG is positive, off otherwise.
Server mode runs a process that accepts commands from the
`emacsclient' program.  See `server-start' and Info node `Emacs server'."
  :global t
  :group 'server
555
  :version "22.1"
Dave Love's avatar
Dave Love committed
556 557 558
  ;; Fixme: Should this check for an existing server socket and do
  ;; nothing if there is one (for multiple Emacs sessions)?
  (server-start (not server-mode)))
root's avatar
root committed
559

560 561 562 563 564 565 566 567 568 569 570 571 572 573
(defun server-eval-and-print (expr proc)
  "Eval EXPR and send the result back to client PROC."
  (let ((v (eval (car (read-from-string expr)))))
    (when (and v proc)
      (with-temp-buffer
        (let ((standard-output (current-buffer)))
          (pp v)
          (let ((text (buffer-substring-no-properties
                       (point-min) (point-max))))
            (server-send-string
             proc (format "-print %s\n"
                          (server-quote-arg text)))))))))

(defun server-create-tty-frame (tty type proc)
574
  (add-to-list 'frame-inherited-parameters 'client)
575 576 577 578 579 580 581
  (let ((frame
         (server-with-environment (process-get proc 'env)
             '("LANG" "LC_CTYPE" "LC_ALL"
               ;; For tgetent(3); list according to ncurses(3).
               "BAUDRATE" "COLUMNS" "ESCDELAY" "HOME" "LINES"
               "NCURSES_ASSUMED_COLORS" "NCURSES_NO_PADDING"
               "NCURSES_NO_SETBUF" "TERM" "TERMCAP" "TERMINFO"
582
               "TERMINFO_DIRS" "TERMPATH"
583 584 585 586 587 588
               ;; rxvt wants these
               "COLORFGBG" "COLORTERM")
           (make-frame-on-tty tty type
                              ;; Ignore nowait here; we always need to
                              ;; clean up opened ttys when the client dies.
                              `((client . ,proc)
589 590 591 592 593 594 595 596 597 598
                                ;; This is a leftover from an earlier
                                ;; attempt at making it possible for process
                                ;; run in the server process to use the
                                ;; environment of the client process.
                                ;; It has no effect now and to make it work
                                ;; we'd need to decide how to make
                                ;; process-environment interact with client
                                ;; envvars, and then to change the
                                ;; C functions `child_setup' and
                                ;; `getenv_internal' accordingly.
599
                                (environment . ,(process-get proc 'env)))))))
600

601 602 603 604
    ;; ttys don't use the `display' parameter, but callproc.c does to set
    ;; the DISPLAY environment on subprocesses.
    (set-frame-parameter frame 'display
                         (getenv-internal "DISPLAY" (process-get proc 'env)))
605
    (select-frame frame)
606 607
    (process-put proc 'frame frame)
    (process-put proc 'terminal (frame-terminal frame))
608 609 610 611 612 613 614 615 616 617

    ;; Display *scratch* by default.
    (switch-to-buffer (get-buffer-create "*scratch*") 'norecord)

    ;; Reply with our pid.
    (server-send-string proc (concat "-emacs-pid "
                                     (number-to-string (emacs-pid)) "\n"))
    frame))

(defun server-create-window-system-frame (display nowait proc)
618
  (add-to-list 'frame-inherited-parameters 'client)
619
  (if (not (fboundp 'make-frame-on-display))
620 621 622 623 624 625 626 627 628 629 630
      (progn
        ;; This emacs does not support X.
        (server-log "Window system unsupported" proc)
        (server-send-string proc "-window-system-unsupported \n")
        nil)
    ;; Flag frame as client-created, but use a dummy client.
    ;; This will prevent the frame from being deleted when
    ;; emacsclient quits while also preventing
    ;; `server-save-buffers-kill-terminal' from unexpectedly
    ;; killing emacs on that frame.
    (let* ((params `((client . ,(if nowait 'nowait proc))
631
                     ;; This is a leftover, see above.
632 633 634 635 636 637
                     (environment . ,(process-get proc 'env))))
           (frame (make-frame-on-display
                   (or display
                       (frame-parameter nil 'display)
                       (getenv "DISPLAY")
                       (error "Please specify display"))
638
                   params)))
639 640
      (server-log (format "%s created" frame) proc)
      (select-frame frame)
641 642
      (process-put proc 'frame frame)
      (process-put proc 'terminal (frame-terminal frame))
643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680

      ;; Display *scratch* by default.
      (switch-to-buffer (get-buffer-create "*scratch*") 'norecord)
      frame)))


(defun server-goto-toplevel (proc)
  (condition-case nil
      ;; If we're running isearch, we must abort it to allow Emacs to
      ;; display the buffer and switch to it.
      (dolist (buffer (buffer-list))
        (with-current-buffer buffer
          (when (bound-and-true-p isearch-mode)
            (isearch-cancel))))
    ;; Signaled by isearch-cancel.
    (quit (message nil)))
  (when (> (recursion-depth) 0)
    ;; We're inside a minibuffer already, so if the emacs-client is trying
    ;; to open a frame on a new display, we might end up with an unusable
    ;; frame because input from that display will be blocked (until exiting
    ;; the minibuffer).  Better exit this minibuffer right away.
    ;; Similarly with recursive-edits such as the splash screen.
    (run-with-timer 0 nil (lexical-let ((proc proc))
			    (lambda () (server-execute-continuation proc))))
    (top-level)))

;; We use various special properties on process objects:
;; - `env' stores the info about the environment of the emacsclient process.
;; - `continuation' is a no-arg function that we need to execute.  It contains
;;   commands we wanted to execute in some earlier invocation of the process
;;   filter but that we somehow were unable to process at that time
;;   (e.g. because we first need to throw to the toplevel).

(defun server-execute-continuation (proc)
  (let ((continuation (process-get proc 'continuation)))
    (process-put proc 'continuation nil)
    (if continuation (ignore-errors (funcall continuation)))))

681
(defun* server-process-filter (proc string)
Dave Love's avatar
Dave Love committed
682
  "Process a request from the server to edit some files.
683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699
PROC is the server process.  STRING consists of a sequence of
commands prefixed by a dash.  Some commands have arguments; these
are &-quoted and need to be decoded by `server-unquote-arg'.  The
filter parses and executes these commands.

To illustrate the protocol, here is an example command that
emacsclient sends to create a new X frame (note that the whole
sequence is sent on a single line):

	-env HOME /home/lorentey
	-env DISPLAY :0.0
	... lots of other -env commands
	-display :0.0
	-window-system

The following commands are accepted by the server:

700 701
`-auth AUTH-STRING'
  Authenticate the client using the secret authentication string
702
  AUTH-STRING.
703

704
`-env NAME=VALUE'
705 706
  An environment variable on the client side.

707 708 709
`-dir DIRNAME'
  The current working directory of the client process.

710 711 712
`-current-frame'
  Forbid the creation of new frames.

713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741
`-nowait'
  Request that the next frame created should not be
  associated with this client.

`-display DISPLAY'
  Set the display name to open X frames on.

`-position LINE[:COLUMN]'
  Go to the given line and column number
  in the next file opened.

`-file FILENAME'
  Load the given file in the current frame.

`-eval EXPR'
  Evaluate EXPR as a Lisp expression and return the
  result in -print commands.

`-window-system'
  Open a new X frame.

`-tty DEVICENAME TYPE'
  Open a new tty frame at the client.

`-suspend'
  Suspend this tty frame.  The client sends this string in
  response to SIGTSTP and SIGTTOU.  The server must cease all I/O
  on this tty until it gets a -resume command.

742
`-resume'
743
  Resume this tty frame.  The client sends this string when it
744 745 746
  gets the SIGCONT signal and it is the foreground process on its
  controlling tty.

747 748 749 750 751 752 753 754 755 756 757 758
`-ignore COMMENT'
  Do nothing, but put the comment in the server
  log.  Useful for debugging.


The following commands are accepted by the client:

`-emacs-pid PID'
  Describes the process id of the Emacs process;
  used to forward window change signals to it.

`-window-system-unsupported'
759 760
  Signals that the server does not support creating X frames;
  the client must try again with a tty frame.
761 762 763 764 765 766 767 768 769

`-print STRING'
  Print STRING on stdout.  Used to send values
  returned by -eval.

`-error DESCRIPTION'
  Signal an error (but continue processing).

`-suspend'
770 771
  Suspend this terminal, i.e., stop the client process.
  Sent when the user presses C-z."
772
  (server-log (concat "Received " string) proc)
773 774
  ;; First things first: let's check the authentication
  (unless (process-get proc :authenticated)
775
    (if (and (string-match "-auth \\([!-~]+\\)\n?" string)
776 777 778 779 780
	     (equal (match-string 1 string) (process-get proc :auth-key)))
	(progn
	  (setq string (substring string (match-end 0)))
	  (process-put proc :authenticated t)
	  (server-log "Authentication successful" proc))
781
      (server-log "Authentication failed" proc)
782 783
      (server-send-string
       proc (concat "-error " (server-quote-arg "Authentication failed")))
784 785 786
      (delete-process proc)
      ;; We return immediately
      (return-from server-process-filter)))
787 788 789 790
  (let ((prev (process-get proc 'previous-string)))
    (when prev
      (setq string (concat prev string))
      (process-put proc 'previous-string nil)))
791
  (condition-case err
792
      (progn
Karoly Lorentey's avatar
Karoly Lorentey committed
793
	(server-add-client proc)
794 795 796 797
	(if (not (string-match "\n" string))
            ;; Save for later any partial line that remains.
            (when (> (length string) 0)
              (process-put proc 'previous-string string))
798

799 800 801 802
          ;; In earlier versions of server.el (where we used an `emacsserver'
          ;; process), there could be multiple lines.  Nowadays this is not
          ;; supported any more.
          (assert (eq (match-end 0) (length string)))
803 804 805 806
	  (let ((request (substring string 0 (match-beginning 0)))
		(coding-system (and default-enable-multibyte-characters
				    (or file-name-coding-system
					default-file-name-coding-system)))
Karoly Lorentey's avatar
Karoly Lorentey committed
807 808
		nowait ; t if emacsclient does not want to wait for us.
		frame ; The frame that was opened for the client (if any).
809
		display		     ; Open the frame on this display.
810
		dontkill       ; t if the client should not be killed.
811
		commands
812
		dir
813
		use-current-frame
814 815 816 817
		tty-name       ;nil, `window-system', or the tty name.
		tty-type             ;string.
		files
		filepos
818 819
		command-line-args-left
		arg)
820 821
	    ;; Remove this line from STRING.
	    (setq string (substring string (match-end 0)))
822 823 824
	    (setq command-line-args-left
		  (mapcar 'server-unquote-arg (split-string request " " t)))
	    (while (setq arg (pop command-line-args-left))
825
		(cond
826
		 ;; -version CLIENT-VERSION: obsolete at birth.
827 828
		 ((and (equal "-version" arg) command-line-args-left)
		  (pop command-line-args-left))
829

Karoly Lorentey's avatar
Karoly Lorentey committed
830
		 ;; -nowait:  Emacsclient won't wait for a result.
831 832
		 ((equal "-nowait" arg) (setq nowait t))

833
		 ;; -current-frame:  Don't create frames.
834
		 ((equal "-current-frame" arg) (setq use-current-frame t))
835

Karoly Lorentey's avatar
Karoly Lorentey committed
836
		 ;; -display DISPLAY:
837
		 ;; Open X frames on the given display instead of the default.
838
		 ((and (equal "-display" arg) command-line-args-left)
839 840
		  (setq display (pop command-line-args-left))
                  (if (zerop (length display)) (setq display nil)))
841

Karoly Lorentey's avatar
Karoly Lorentey committed
842
		 ;; -window-system:  Open a new X frame.
843
		 ((equal "-window-system" arg)
844 845
                  (setq dontkill t)
                  (setq tty-name 'window-system))
Karoly Lorentey's avatar
Karoly Lorentey committed
846 847

		 ;; -resume:  Resume a suspended tty frame.
848
		 ((equal "-resume" arg)
849
		  (lexical-let ((terminal (process-get proc 'terminal)))
850
		    (setq dontkill t)
851 852 853 854
                    (push (lambda ()
                            (when (eq (terminal-live-p terminal) t)
                              (resume-tty terminal)))
                          commands)))
855

Karoly Lorentey's avatar
Karoly Lorentey committed
856 857 858
		 ;; -suspend:  Suspend the client's frame.  (In case we
		 ;; get out of sync, and a C-z sends a SIGTSTP to
		 ;; emacsclient.)
859
		 ((equal "-suspend" arg)
860
		  (lexical-let ((terminal (process-get proc 'terminal)))
861
		    (setq dontkill t)
862 863 864 865
                    (push (lambda ()
                            (when (eq (terminal-live-p terminal) t)
                              (suspend-tty terminal)))
                          commands)))
866

Karoly Lorentey's avatar
Karoly Lorentey committed
867 868
		 ;; -ignore COMMENT:  Noop; useful for debugging emacsclient.
		 ;; (The given comment appears in the server log.)
869 870 871
		 ((and (equal "-ignore" arg) command-line-args-left
		  (setq dontkill t)
		  (pop command-line-args-left)))
872

Karoly Lorentey's avatar
Karoly Lorentey committed
873
		 ;; -tty DEVICE-NAME TYPE:  Open a new tty frame at the client.
874
		 ((and (equal "-tty" arg)
875 876 877
                       (cdr command-line-args-left))
                  (setq tty-name (pop command-line-args-left)
			tty-type (pop command-line-args-left)
878 879
			dontkill (or dontkill
				     (not use-current-frame))))
880 881 882 883

		 ;; -position LINE[:COLUMN]:  Set point to the given
		 ;;  position in the next file.
		 ((and (equal "-position" arg)
884 885 886 887
		       command-line-args-left
                       (string-match "\\+\\([0-9]+\\)\\(?::\\([0-9]+\\)\\)?"
                                     (car command-line-args-left)))
		  (setq arg (pop command-line-args-left))
888 889 890
		  (setq filepos
                        (cons (string-to-number (match-string 1 arg))
                              (string-to-number (or (match-string 2 arg) "")))))
891

Karoly Lorentey's avatar
Karoly Lorentey committed
892
		 ;; -file FILENAME:  Load the given file.
893
		 ((and (equal "-file" arg)
894 895
		       command-line-args-left)
		  (let ((file (pop command-line-args-left)))
896 897 898
		    (if coding-system
			(setq file (decode-coding-string file coding-system)))
		    (setq file (command-line-normalize-file-name file))
899 900 901 902
		    (push (cons file filepos) files)
		    (server-log (format "New file: %s %s"
                                        file (or filepos "")) proc))
		  (setq filepos nil))
903

Karoly Lorentey's avatar
Karoly Lorentey committed
904
		 ;; -eval EXPR:  Evaluate a Lisp expression.
905
		 ((and (equal "-eval" arg)
906
                       command-line-args-left)
907 908
		  (if use-current-frame
		      (setq use-current-frame 'always))
909
		  (lexical-let ((expr (pop command-line-args-left)))
910 911
		    (if coding-system
			(setq expr (decode-coding-string expr coding-system)))
912 913
                    (push (lambda () (server-eval-and-print expr proc))
                          commands)
914
		    (setq filepos nil)))
915

916
		 ;; -env NAME=VALUE:  An environment variable.
917 918
		 ((and (equal "-env" arg) command-line-args-left)
		  (let ((var (pop command-line-args-left)))
919
		    ;; XXX Variables should be encoded as in getenv/setenv.
920 921
                    (process-put proc 'env
                                 (cons var (process-get proc 'env)))))
Karoly Lorentey's avatar
Karoly Lorentey committed
922

923
		 ;; -dir DIRNAME:  The cwd of the emacsclient process.
924 925
		 ((and (equal "-dir" arg) command-line-args-left)
		  (setq dir (pop command-line-args-left))
926 927 928 929
		  (if coding-system
		      (setq dir (decode-coding-string dir coding-system)))
		  (setq dir (command-line-normalize-file-name dir)))

930
		 ;; Unknown command.
931
		 (t (error "Unknown command: %s" arg))))
932

933 934 935 936 937 938
	    (setq frame
		  (cond
		   ((and use-current-frame
			 (or (eq use-current-frame 'always)
			     ;; We can't use the Emacs daemon's
			     ;; terminal frame.
939 940
			     (not (and (daemonp)
				       (= (length (frame-list)) 1)
941 942
				       (eq (selected-frame)
					   terminal-frame)))))
943
		    (setq tty-name nil tty-type nil)
944 945 946
		    (if display (server-select-display display)))
		   ((eq tty-name 'window-system)
		    (server-create-window-system-frame display nowait proc))
947 948 949
		   ;; When resuming on a tty, tty-name is nil.
		   (tty-name
		    (server-create-tty-frame tty-name tty-type proc))))
950

Stefan Monnier's avatar
Stefan Monnier committed
951 952 953 954 955 956 957 958 959 960 961 962 963 964 965
            (process-put
             proc 'continuation
             (lexical-let ((proc proc)
                           (files files)
                           (nowait nowait)
                           (commands commands)
                           (dontkill dontkill)
                           (frame frame)
                           (dir dir)
                           (tty-name tty-name))
               (lambda ()
                 (with-current-buffer (get-buffer-create server-buffer)
                   ;; Use the same cwd as the emacsclient, if possible, so
                   ;; relative file names work correctly, even in `eval'.
                   (let ((default-directory
966 967
			  (if (and dir (file-directory-p dir))
			      dir default-directory)))
Stefan Monnier's avatar
Stefan Monnier committed
968 969
                     (server-execute proc files nowait commands
                                     dontkill frame tty-name))))))
970 971 972 973 974

            (when (or frame files)
              (server-goto-toplevel proc))

            (server-execute-continuation proc))))
975
    ;; condition-case
976 977 978 979
    (error (server-return-error proc err))))

(defun server-execute (proc files nowait commands dontkill frame tty-name)
  (condition-case err
980
      (let* ((buffers
981 982
              (when files
                (run-hooks 'pre-command-hook)
983
                (prog1 (server-visit-files files proc nowait)
984 985 986
                  (run-hooks 'post-command-hook)))))

        (mapc 'funcall (nreverse commands))
987

988 989 990 991 992 993 994 995 996 997 998 999