1 ;;; server.el --- Lisp code for GNU Emacs running as server process
3 ;; Copyright (C) 1986, 1987, 1992, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
4 ;; 2001, 2002, 2003, 2004, 2005, 2006, 2007 Free Software Foundation, Inc.
6 ;; Author: William Sommerfeld <wesommer@athena.mit.edu>
10 ;; Changes by peck@sun.com and by rms.
11 ;; Overhaul by Karoly Lorentey <lorentey@elte.hu> for multi-tty support.
13 ;; This file is part of GNU Emacs.
15 ;; GNU Emacs is free software; you can redistribute it and/or modify
16 ;; it under the terms of the GNU General Public License as published by
17 ;; the Free Software Foundation; either version 3, or (at your option)
20 ;; GNU Emacs is distributed in the hope that it will be useful,
21 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
22 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
23 ;; GNU General Public License for more details.
25 ;; You should have received a copy of the GNU General Public License
26 ;; along with GNU Emacs; see the file COPYING. If not, write to the
27 ;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
28 ;; Boston, MA 02110-1301, USA.
32 ;; This Lisp code is run in Emacs when it is to operate as
33 ;; a server for other processes.
35 ;; Load this library and do M-x server-edit to enable Emacs as a server.
36 ;; Emacs opens up a socket for communication with clients. If there are no
37 ;; client buffers to edit, server-edit acts like (switch-to-buffer
40 ;; When some other program runs "the editor" to edit a file,
41 ;; "the editor" can be the Emacs client program ../lib-src/emacsclient.
42 ;; This program transmits the file names to Emacs through
43 ;; the server subprocess, and Emacs visits them and lets you edit them.
45 ;; Note that any number of clients may dispatch files to Emacs to be edited.
47 ;; When you finish editing a Server buffer, again call server-edit
48 ;; to mark that buffer as done for the client and switch to the next
49 ;; Server buffer. When all the buffers for a client have been edited
50 ;; and exited with server-edit, the client "editor" will return
51 ;; to the program that invoked it.
53 ;; Your editing commands and Emacs's display output go to and from
54 ;; the terminal in the usual way. Thus, server operation is possible
55 ;; only when Emacs can talk to the terminal at the time you invoke
56 ;; the client. This is possible in four cases:
58 ;; 1. On a window system, where Emacs runs in one window and the
59 ;; program that wants to use "the editor" runs in another.
61 ;; 2. On a multi-terminal system, where Emacs runs on one terminal and the
62 ;; program that wants to use "the editor" runs on another.
64 ;; 3. When the program that wants to use "the editor" is running
65 ;; as a subprocess of Emacs.
67 ;; 4. On a system with job control, when Emacs is suspended, the program
68 ;; that wants to use "the editor" will stop and display
69 ;; "Waiting for Emacs...". It can then be suspended, and Emacs can be
70 ;; brought into the foreground for editing. When done editing, Emacs is
71 ;; suspended again, and the client program is brought into the foreground.
73 ;; The buffer local variable "server-buffer-clients" lists
74 ;; the clients who are waiting for this buffer to be edited.
75 ;; The global variable "server-clients" lists all the waiting clients,
76 ;; and which files are yet to be edited for each.
80 ;; - handle command-line-args-left.
81 ;; - move most of the args processing and decision making from emacsclient.c
83 ;; - fix up handling of the client's environment (place it in the terminal?).
87 (eval-when-compile (require 'cl))
90 "Emacs running as a server process."
93 (defcustom server-use-tcp nil
94 "If non-nil, use TCP sockets instead of local sockets."
95 :set #'(lambda (sym val)
96 (unless (featurep 'make-network-process '(:family local))
98 (unless load-in-progress
99 (message "Local sockets unsupported, using TCP sockets")))
100 (when val (random t))
101 (set-default sym val))
106 (defcustom server-host nil
107 "The name or IP address to use as host address of the server process.
108 If set, the server accepts remote connections; otherwise it is local."
111 (string :tag "Name or IP address")
112 (const :tag "Local" nil))
114 (put 'server-host 'risky-local-variable t)
116 (defcustom server-auth-dir (concat user-emacs-directory "server/")
117 "Directory for server authentication files."
121 (put 'server-auth-dir 'risky-local-variable t)
123 (defcustom server-raise-frame t
124 "If non-nil, raise frame when switching to a buffer."
129 (defcustom server-visit-hook nil
130 "Hook run when visiting a file for the Emacs server."
134 (defcustom server-switch-hook nil
135 "Hook run when switching to a buffer for the Emacs server."
139 (defcustom server-done-hook nil
140 "Hook run when done editing a buffer for the Emacs server."
144 (defvar server-process nil
145 "The current server process.")
147 (defvar server-clients nil
148 "List of current server clients.
149 Each element is a process.")
151 (defvar server-buffer-clients nil
152 "List of client processes requesting editing of current buffer.")
153 (make-variable-buffer-local 'server-buffer-clients)
154 ;; Changing major modes should not erase this local.
155 (put 'server-buffer-clients 'permanent-local t)
157 (defcustom server-window nil
158 "Specification of the window to use for selecting Emacs server buffers.
159 If nil, use the selected window.
160 If it is a function, it should take one argument (a buffer) and
161 display and select it. A common value is `pop-to-buffer'.
162 If it is a window, use that.
163 If it is a frame, use the frame's selected window.
165 It is not meaningful to set this to a specific frame or window with Custom.
166 Only programs can do so."
169 :type '(choice (const :tag "Use selected window"
170 :match (lambda (widget value)
171 (not (functionp value)))
173 (function-item :tag "Display in new frame" switch-to-buffer-other-frame)
174 (function-item :tag "Use pop-to-buffer" pop-to-buffer)
175 (function :tag "Other function")))
177 (defcustom server-temp-file-regexp "^/tmp/Re\\|/draft$"
178 "Regexp matching names of temporary files.
179 These are deleted and reused after each edit by the programs that
180 invoke the Emacs server."
184 (defcustom server-kill-new-buffers t
185 "Whether to kill buffers when done with them.
186 If non-nil, kill a buffer unless it already existed before editing
187 it with the Emacs server. If nil, kill only buffers as specified by
188 `server-temp-file-regexp'.
189 Please note that only buffers that still have a client are killed,
190 i.e. buffers visited with \"emacsclient --no-wait\" are never killed in
196 (or (assq 'server-buffer-clients minor-mode-alist)
197 (push '(server-buffer-clients " Server") minor-mode-alist))
199 (defvar server-existing-buffer nil
200 "Non-nil means the buffer existed before the server was asked to visit it.
201 This means that the server should not kill the buffer when you say you
202 are done with it in the server.")
203 (make-variable-buffer-local 'server-existing-buffer)
205 (defvar server-name "server")
207 (defvar server-socket-dir nil
208 "The directory in which to place the server socket.
209 Initialized by `server-start'.")
211 (defun server-clients-with (property value)
212 "Return a list of clients with PROPERTY set to VALUE."
214 (dolist (proc server-clients result)
215 (when (equal value (process-get proc property))
216 (push proc result)))))
218 (defun server-add-client (proc)
219 "Create a client for process PROC, if it doesn't already have one.
220 New clients have no properties."
221 (add-to-list 'server-clients proc))
223 (defmacro server-with-environment (env vars &rest body)
224 "Evaluate BODY with environment variables VARS set to those in ENV.
225 The environment variables are then restored to their previous values.
227 VARS should be a list of strings.
228 ENV should be in the same format as `process-environment'."
230 (let ((var (make-symbol "var"))
231 (value (make-symbol "value")))
232 `(let ((process-environment process-environment))
234 (let ((,value (getenv-internal ,var ,env)))
235 (push (if (null ,value)
237 (concat ,var "=" ,value))
238 process-environment)))
241 (defun server-delete-client (proc &optional noframe)
242 "Delete PROC, including its buffers, terminals and frames.
243 If NOFRAME is non-nil, let the frames live. (To be used from
244 `delete-frame-functions'.)"
245 (server-log (concat "server-delete-client" (if noframe " noframe")) proc)
246 ;; Force a new lookup of client (prevents infinite recursion).
247 (when (memq proc server-clients)
248 (let ((buffers (process-get proc 'buffers)))
250 ;; Kill the client's buffers.
251 (dolist (buf buffers)
252 (when (buffer-live-p buf)
253 (with-current-buffer buf
254 ;; Kill the buffer if necessary.
255 (when (and (equal server-buffer-clients
257 (or (and server-kill-new-buffers
258 (not server-existing-buffer))
259 (server-temp-file-p))
260 (not (buffer-modified-p)))
263 (progn (setq server-buffer-clients nil)
264 (kill-buffer (current-buffer))
267 ;; Restore clients if user pressed C-g in `kill-buffer'.
268 (setq server-buffer-clients (list proc)))))))))
270 ;; Delete the client's frames.
272 (dolist (frame (frame-list))
273 (when (and (frame-live-p frame)
274 (equal proc (frame-parameter frame 'client)))
275 ;; Prevent `server-handle-delete-frame' from calling us
277 (set-frame-parameter frame 'client nil)
278 (delete-frame frame))))
280 (setq server-clients (delq proc server-clients))
282 ;; Delete the client's tty.
283 (let ((terminal (process-get proc 'terminal)))
284 ;; Only delete the terminal if it is non-nil.
285 (when (and terminal (eq (terminal-live-p terminal) t))
286 (delete-terminal terminal)))
288 ;; Delete the client's process.
289 (if (eq (process-status proc) 'open)
290 (delete-process proc))
292 (server-log "Deleted" proc))))
294 (defun server-log (string &optional client)
295 "If a *server* buffer exists, write STRING to it for logging purposes.
296 If CLIENT is non-nil, add a description of it to the logged message."
297 (when (get-buffer "*server*")
298 (with-current-buffer "*server*"
299 (goto-char (point-max))
300 (insert (current-time-string)
303 ((listp client) (format " %s: " (car client)))
304 (t (format " %s: " client)))
306 (or (bolp) (newline)))))
308 (defun server-sentinel (proc msg)
309 "The process sentinel for Emacs server connections."
310 ;; If this is a new client process, set the query-on-exit flag to nil
311 ;; for this process (it isn't inherited from the server process).
312 (when (and (eq (process-status proc) 'open)
313 (process-query-on-exit-flag proc))
314 (set-process-query-on-exit-flag proc nil))
315 ;; Delete the associated connection file, if applicable.
316 ;; This is actually problematic: the file may have been overwritten by
317 ;; another Emacs server in the mean time, so it's not ours any more.
318 ;; (and (process-contact proc :server)
319 ;; (eq (process-status proc) 'closed)
320 ;; (ignore-errors (delete-file (process-get proc :server-file))))
321 (server-log (format "Status changed to %s: %s" (process-status proc) msg) proc)
322 (server-delete-client proc))
324 (defun server-select-display (display)
325 ;; If the current frame is on `display' we're all set.
326 ;; Similarly if we are unable to open a frames on other displays, there's
327 ;; nothing more we can do.
328 (unless (or (not (fboundp 'make-frame-on-display))
329 (equal (frame-parameter (selected-frame) 'display) display))
330 ;; Otherwise, look for an existing frame there and select it.
331 (dolist (frame (frame-list))
332 (when (equal (frame-parameter frame 'display) display)
333 (select-frame frame)))
334 ;; If there's no frame on that display yet, create and select one.
335 (unless (equal (frame-parameter (selected-frame) 'display) display)
336 (let* ((buffer (generate-new-buffer " *server-dummy*"))
337 (frame (make-frame-on-display
339 ;; Make it display (and remember) some dummy buffer, so
340 ;; we can detect later if the frame is in use or not.
341 `((server-dummy-buffer . ,buffer)
342 ;; This frame may be deleted later (see
343 ;; server-unselect-display) so we want it to be as
344 ;; unobtrusive as possible.
345 (visibility . nil)))))
347 (set-window-buffer (selected-window) buffer)
350 (defun server-unselect-display (frame)
351 (when (frame-live-p frame)
352 ;; If the temporary frame is in use (displays something real), make it
353 ;; visible. If not (which can happen if the user's customizations call
354 ;; pop-to-buffer etc.), delete it to avoid preserving the connection after
355 ;; the last real frame is deleted.
356 (if (and (eq (frame-first-window frame)
357 (next-window (frame-first-window frame) 'nomini))
358 (eq (window-buffer (frame-first-window frame))
359 (frame-parameter frame 'server-dummy-buffer)))
360 ;; The temp frame still only shows one buffer, and that is the
361 ;; internal temp buffer.
363 (set-frame-parameter frame 'visibility t))
364 (kill-buffer (frame-parameter frame 'server-dummy-buffer))
365 (set-frame-parameter frame 'server-dummy-buffer nil)))
367 (defun server-handle-delete-frame (frame)
368 "Delete the client connection when the emacsclient frame is deleted."
369 (let ((proc (frame-parameter frame 'client)))
370 (when (and (frame-live-p frame)
372 ;; See if this is the last frame for this client.
373 (>= 1 (let ((frame-num 0))
374 (dolist (f (frame-list))
375 (when (eq proc (frame-parameter f 'client))
376 (setq frame-num (1+ frame-num))))
378 (server-log (format "server-handle-delete-frame, frame %s" frame) proc)
379 (server-delete-client proc 'noframe)))) ; Let delete-frame delete the frame later.
381 (defun server-handle-suspend-tty (terminal)
382 "Notify the emacsclient process to suspend itself when its tty device is suspended."
383 (dolist (proc (server-clients-with 'terminal terminal))
384 (server-log (format "server-handle-suspend-tty, terminal %s" terminal) proc)
386 (server-send-string proc "-suspend \n")
387 (file-error ;The pipe/socket was closed.
388 (ignore-errors (server-delete-client proc))))))
390 (defun server-unquote-arg (arg)
391 "Remove &-quotation from ARG.
392 See `server-quote-arg' and `server-process-filter'."
393 (replace-regexp-in-string
402 (defun server-quote-arg (arg)
403 "In ARG, insert a & before each &, each space, each newline, and -.
404 Change spaces to underscores, too, so that the return value never
407 See `server-unquote-arg' and `server-process-filter'."
408 (replace-regexp-in-string
409 "[-&\n ]" (lambda (s)
417 (defun server-send-string (proc string)
418 "A wrapper around `proc-send-string' for logging."
419 (server-log (concat "Sent " string) proc)
420 (process-send-string proc string))
422 (defun server-ensure-safe-dir (dir)
423 "Make sure DIR is a directory with no race-condition issues.
424 Creates the directory if necessary and makes sure:
425 - there's no symlink involved
427 - it's not readable/writable by anybody else."
428 (setq dir (directory-file-name dir))
429 (let ((attrs (file-attributes dir)))
431 (letf (((default-file-modes) ?\700)) (make-directory dir t))
432 (setq attrs (file-attributes dir)))
433 ;; Check that it's safe for use.
434 (unless (and (eq t (car attrs)) (eql (nth 2 attrs) (user-uid))
435 (or (eq system-type 'windows-nt)
436 (zerop (logand ?\077 (file-modes dir)))))
437 (error "The directory %s is unsafe" dir))))
440 (defun server-start (&optional leave-dead)
441 "Allow this Emacs process to be a server for client processes.
442 This starts a server communications subprocess through which
443 client \"editors\" can send your editing commands to this Emacs
444 job. To use the server, set up the program `emacsclient' in the
445 Emacs distribution as your standard \"editor\".
447 Optional argument LEAVE-DEAD (interactively, a prefix arg) means just
448 kill any existing server communications subprocess."
453 "The current server still has clients; delete them? "))
454 ;; It is safe to get the user id now.
455 (setq server-socket-dir (or server-socket-dir
456 (format "/tmp/emacs%d" (user-uid))))
459 (ignore-errors (delete-process server-process)))
460 ;; Delete the socket files made by previous server invocations.
462 (delete-file (expand-file-name server-name server-socket-dir))
464 ;; If this Emacs already had a server, clear out associated status.
465 (while server-clients
466 (server-delete-client (car server-clients)))
467 ;; Now any previous server is properly stopped.
470 (server-log (message "Server stopped"))
471 (setq server-process nil))
472 (let* ((server-dir (if server-use-tcp server-auth-dir server-socket-dir))
473 (server-file (expand-file-name server-name server-dir)))
474 ;; Make sure there is a safe directory in which to place the socket.
475 (server-ensure-safe-dir server-dir)
476 ;; Remove any leftover socket or authentication file.
477 (ignore-errors (delete-file server-file))
479 (server-log (message "Restarting server")))
480 (letf (((default-file-modes) ?\700))
481 (add-hook 'suspend-tty-functions 'server-handle-suspend-tty)
482 (add-hook 'delete-frame-functions 'server-handle-delete-frame)
483 (add-hook 'kill-buffer-query-functions 'server-kill-buffer-query-function)
484 (add-hook 'kill-emacs-query-functions 'server-kill-emacs-query-function)
485 (add-hook 'kill-emacs-hook (lambda () (server-mode -1))) ;Cleanup upon exit.
487 (apply #'make-network-process
491 :sentinel 'server-sentinel
492 :filter 'server-process-filter
493 ;; We must receive file names without being decoded.
494 ;; Those are decoded by server-process-filter according
495 ;; to file-name-coding-system.
497 ;; The rest of the args depends on the kind of socket used.
501 :host (or server-host 'local)
502 :plist '(:authenticated nil))
505 :plist '(:authenticated t)))))
506 (unless server-process (error "Could not start server process"))
510 ;; The auth key is a 64-byte string of random chars in the
513 collect (+ 33 (random 94)) into auth
514 finally return (concat auth))))
515 (process-put server-process :auth-key auth-key)
516 (with-temp-file server-file
517 (set-buffer-multibyte nil)
518 (setq buffer-file-coding-system 'no-conversion)
519 (insert (format-network-address
520 (process-contact server-process :local))
521 " " (int-to-string (emacs-pid))
522 "\n" auth-key)))))))))
524 (defun server-running-p (&optional name)
525 "Test whether server NAME is running."
527 (list (if current-prefix-arg
528 (read-string "Server name: " nil nil server-name))))
529 (unless name (setq name server-name))
533 (make-network-process
534 :name "server-client-test" :family 'local :server nil :noquery t
535 :service (expand-file-name name server-socket-dir)))
540 (define-minor-mode server-mode
542 With ARG, turn Server mode on if ARG is positive, off otherwise.
543 Server mode runs a process that accepts commands from the
544 `emacsclient' program. See `server-start' and Info node `Emacs server'."
548 ;; Fixme: Should this check for an existing server socket and do
549 ;; nothing if there is one (for multiple Emacs sessions)?
550 (server-start (not server-mode)))
552 (defun server-eval-and-print (expr proc)
553 "Eval EXPR and send the result back to client PROC."
554 (let ((v (eval (car (read-from-string expr)))))
557 (let ((standard-output (current-buffer)))
559 (let ((text (buffer-substring-no-properties
560 (point-min) (point-max))))
562 proc (format "-print %s\n"
563 (server-quote-arg text)))))))))
565 (defun server-create-tty-frame (tty type proc)
566 (add-to-list 'frame-inherited-parameters 'client)
568 (server-with-environment (process-get proc 'env)
569 '("LANG" "LC_CTYPE" "LC_ALL"
570 ;; For tgetent(3); list according to ncurses(3).
571 "BAUDRATE" "COLUMNS" "ESCDELAY" "HOME" "LINES"
572 "NCURSES_ASSUMED_COLORS" "NCURSES_NO_PADDING"
573 "NCURSES_NO_SETBUF" "TERM" "TERMCAP" "TERMINFO"
574 "TERMINFO_DIRS" "TERMPATH"
576 "COLORFGBG" "COLORTERM")
577 (make-frame-on-tty tty type
578 ;; Ignore nowait here; we always need to
579 ;; clean up opened ttys when the client dies.
581 ;; This is a leftover from an earlier
582 ;; attempt at making it possible for process
583 ;; run in the server process to use the
584 ;; environment of the client process.
585 ;; It has no effect now and to make it work
586 ;; we'd need to decide how to make
587 ;; process-environment interact with client
588 ;; envvars, and then to change the
589 ;; C functions `child_setup' and
590 ;; `getenv_internal' accordingly.
591 (environment . ,(process-get proc 'env)))))))
593 ;; ttys don't use the `display' parameter, but callproc.c does to set
594 ;; the DISPLAY environment on subprocesses.
595 (set-frame-parameter frame 'display
596 (getenv-internal "DISPLAY" (process-get proc 'env)))
598 (process-put proc 'frame frame)
599 (process-put proc 'terminal (frame-terminal frame))
601 ;; Display *scratch* by default.
602 (switch-to-buffer (get-buffer-create "*scratch*") 'norecord)
604 ;; Reply with our pid.
605 (server-send-string proc (concat "-emacs-pid "
606 (number-to-string (emacs-pid)) "\n"))
609 (defun server-create-window-system-frame (display nowait proc)
610 (add-to-list 'frame-inherited-parameters 'client)
611 (if (not (fboundp 'make-frame-on-display))
613 ;; This emacs does not support X.
614 (server-log "Window system unsupported" proc)
615 (server-send-string proc "-window-system-unsupported \n")
617 ;; Flag frame as client-created, but use a dummy client.
618 ;; This will prevent the frame from being deleted when
619 ;; emacsclient quits while also preventing
620 ;; `server-save-buffers-kill-terminal' from unexpectedly
621 ;; killing emacs on that frame.
622 (let* ((params `((client . ,(if nowait 'nowait proc))
623 ;; This is a leftover, see above.
624 (environment . ,(process-get proc 'env))))
625 (frame (make-frame-on-display
627 (frame-parameter nil 'display)
629 (error "Please specify display"))
631 (server-log (format "%s created" frame) proc)
632 ;; XXX We need to ensure the parameters are really set because Emacs
633 ;; forgets unhandled initialization parameters for X frames at
635 (modify-frame-parameters frame params)
637 (process-put proc 'frame frame)
638 (process-put proc 'terminal (frame-terminal frame))
640 ;; Display *scratch* by default.
641 (switch-to-buffer (get-buffer-create "*scratch*") 'norecord)
645 (defun server-goto-toplevel (proc)
647 ;; If we're running isearch, we must abort it to allow Emacs to
648 ;; display the buffer and switch to it.
649 (dolist (buffer (buffer-list))
650 (with-current-buffer buffer
651 (when (bound-and-true-p isearch-mode)
653 ;; Signaled by isearch-cancel.
654 (quit (message nil)))
655 (when (> (recursion-depth) 0)
656 ;; We're inside a minibuffer already, so if the emacs-client is trying
657 ;; to open a frame on a new display, we might end up with an unusable
658 ;; frame because input from that display will be blocked (until exiting
659 ;; the minibuffer). Better exit this minibuffer right away.
660 ;; Similarly with recursive-edits such as the splash screen.
661 (run-with-timer 0 nil (lexical-let ((proc proc))
662 (lambda () (server-execute-continuation proc))))
665 ;; We use various special properties on process objects:
666 ;; - `env' stores the info about the environment of the emacsclient process.
667 ;; - `continuation' is a no-arg function that we need to execute. It contains
668 ;; commands we wanted to execute in some earlier invocation of the process
669 ;; filter but that we somehow were unable to process at that time
670 ;; (e.g. because we first need to throw to the toplevel).
672 (defun server-execute-continuation (proc)
673 (let ((continuation (process-get proc 'continuation)))
674 (process-put proc 'continuation nil)
675 (if continuation (ignore-errors (funcall continuation)))))
677 (defun* server-process-filter (proc string)
678 "Process a request from the server to edit some files.
679 PROC is the server process. STRING consists of a sequence of
680 commands prefixed by a dash. Some commands have arguments; these
681 are &-quoted and need to be decoded by `server-unquote-arg'. The
682 filter parses and executes these commands.
684 To illustrate the protocol, here is an example command that
685 emacsclient sends to create a new X frame (note that the whole
686 sequence is sent on a single line):
688 -env HOME /home/lorentey
690 ... lots of other -env commands
694 The following commands are accepted by the server:
697 Authenticate the client using the secret authentication string
701 An environment variable on the client side.
704 The current working directory of the client process.
707 Forbid the creation of new frames.
710 Request that the next frame created should not be
711 associated with this client.
714 Set the display name to open X frames on.
716 `-position LINE[:COLUMN]'
717 Go to the given line and column number
718 in the next file opened.
721 Load the given file in the current frame.
724 Evaluate EXPR as a Lisp expression and return the
725 result in -print commands.
730 `-tty DEVICENAME TYPE'
731 Open a new tty frame at the client.
734 Suspend this tty frame. The client sends this string in
735 response to SIGTSTP and SIGTTOU. The server must cease all I/O
736 on this tty until it gets a -resume command.
739 Resume this tty frame. The client sends this string when it
740 gets the SIGCONT signal and it is the foreground process on its
744 Do nothing, but put the comment in the server
745 log. Useful for debugging.
748 The following commands are accepted by the client:
751 Describes the process id of the Emacs process;
752 used to forward window change signals to it.
754 `-window-system-unsupported'
755 Signals that the server does not support creating X frames;
756 the client must try again with a tty frame.
759 Print STRING on stdout. Used to send values
763 Signal an error (but continue processing).
766 Suspend this terminal, i.e., stop the client process.
767 Sent when the user presses C-z."
768 (server-log (concat "Received " string) proc)
769 ;; First things first: let's check the authentication
770 (unless (process-get proc :authenticated)
771 (if (and (string-match "-auth \\(.*?\\)\n" string)
772 (equal (match-string 1 string) (process-get proc :auth-key)))
774 (setq string (substring string (match-end 0)))
775 (process-put proc :authenticated t)
776 (server-log "Authentication successful" proc))
777 (server-log "Authentication failed" proc)
779 proc (concat "-error " (server-quote-arg "Authentication failed")))
780 (delete-process proc)
781 ;; We return immediately
782 (return-from server-process-filter)))
783 (let ((prev (process-get proc 'previous-string)))
785 (setq string (concat prev string))
786 (process-put proc 'previous-string nil)))
789 (server-add-client proc)
790 (if (not (string-match "\n" string))
791 ;; Save for later any partial line that remains.
792 (when (> (length string) 0)
793 (process-put proc 'previous-string string))
795 ;; In earlier versions of server.el (where we used an `emacsserver'
796 ;; process), there could be multiple lines. Nowadays this is not
797 ;; supported any more.
798 (assert (eq (match-end 0) (length string)))
799 (let ((request (substring string 0 (match-beginning 0)))
800 (coding-system (and default-enable-multibyte-characters
801 (or file-name-coding-system
802 default-file-name-coding-system)))
803 nowait ; t if emacsclient does not want to wait for us.
804 frame ; The frame that was opened for the client (if any).
805 display ; Open the frame on this display.
806 dontkill ; t if the client should not be killed.
809 (tty-name nil) ;nil, `window-system', or the tty name.
814 command-line-args-left
816 ;; Remove this line from STRING.
817 (setq string (substring string (match-end 0)))
818 (setq command-line-args-left
819 (mapcar 'server-unquote-arg (split-string request " " t)))
820 (while (setq arg (pop command-line-args-left))
822 ;; -version CLIENT-VERSION: obsolete at birth.
823 ((and (equal "-version" arg) command-line-args-left)
824 (pop command-line-args-left))
826 ;; -nowait: Emacsclient won't wait for a result.
827 ((equal "-nowait" arg) (setq nowait t))
829 ;; -current-frame: Don't create frames.
830 ((equal "-current-frame" arg) (setq tty-name nil))
833 ;; Open X frames on the given display instead of the default.
834 ((and (equal "-display" arg) command-line-args-left)
835 (setq display (pop command-line-args-left))
836 (if (zerop (length display)) (setq display nil)))
838 ;; -window-system: Open a new X frame.
839 ((equal "-window-system" arg)
841 (setq tty-name 'window-system))
843 ;; -resume: Resume a suspended tty frame.
844 ((equal "-resume" arg)
845 (lexical-let ((terminal (process-get proc 'terminal)))
848 (when (eq (terminal-live-p terminal) t)
849 (resume-tty terminal)))
852 ;; -suspend: Suspend the client's frame. (In case we
853 ;; get out of sync, and a C-z sends a SIGTSTP to
855 ((equal "-suspend" arg)
856 (lexical-let ((terminal (process-get proc 'terminal)))
859 (when (eq (terminal-live-p terminal) t)
860 (suspend-tty terminal)))
863 ;; -ignore COMMENT: Noop; useful for debugging emacsclient.
864 ;; (The given comment appears in the server log.)
865 ((and (equal "-ignore" arg) command-line-args-left
867 (pop command-line-args-left)))
869 ;; -tty DEVICE-NAME TYPE: Open a new tty frame at the client.
870 ((and (equal "-tty" arg)
871 (cdr command-line-args-left))
872 (setq tty-name (pop command-line-args-left)
873 tty-type (pop command-line-args-left)
876 ;; -position LINE[:COLUMN]: Set point to the given
877 ;; position in the next file.
878 ((and (equal "-position" arg)
879 command-line-args-left
880 (string-match "\\+\\([0-9]+\\)\\(?::\\([0-9]+\\)\\)?"
881 (car command-line-args-left)))
882 (setq arg (pop command-line-args-left))
883 (setq lineno (string-to-number (match-string 1 arg))
884 columnno (if (null (match-end 2)) 0
885 (string-to-number (match-string 2 arg)))))
887 ;; -file FILENAME: Load the given file.
888 ((and (equal "-file" arg)
889 command-line-args-left)
890 (let ((file (pop command-line-args-left)))
892 (setq file (decode-coding-string file coding-system)))
893 (setq file (command-line-normalize-file-name file))
894 (push (list file lineno columnno) files)
895 (server-log (format "New file: %s (%d:%d)"
896 file lineno columnno) proc))
900 ;; -eval EXPR: Evaluate a Lisp expression.
901 ((and (equal "-eval" arg)
902 command-line-args-left)
903 (lexical-let ((expr (pop command-line-args-left)))
905 (setq expr (decode-coding-string expr coding-system)))
906 (push (lambda () (server-eval-and-print expr proc))
911 ;; -env NAME=VALUE: An environment variable.
912 ((and (equal "-env" arg) command-line-args-left)
913 (let ((var (pop command-line-args-left)))
914 ;; XXX Variables should be encoded as in getenv/setenv.
915 (process-put proc 'env
916 (cons var (process-get proc 'env)))))
918 ;; -dir DIRNAME: The cwd of the emacsclient process.
919 ((and (equal "-dir" arg) command-line-args-left)
920 (setq dir (pop command-line-args-left))
922 (setq dir (decode-coding-string dir coding-system)))
923 (setq dir (command-line-normalize-file-name dir)))
926 (t (error "Unknown command: %s" arg))))
930 ((nil) (if display (server-select-display display)))
932 (server-create-window-system-frame display nowait proc))
933 (t (server-create-tty-frame tty-name tty-type proc))))
935 (process-put proc 'continuation
936 (lexical-let ((proc proc)
944 (server-execute proc files nowait commands
945 dontkill frame tty-name))))
947 (when (or frame files)
948 (server-goto-toplevel proc))
950 (server-execute-continuation proc))))
952 (error (server-return-error proc err))))
954 (defun server-execute (proc files nowait commands dontkill frame tty-name)
958 (run-hooks 'pre-command-hook)
959 (prog1 (server-visit-files files proc nowait)
960 (run-hooks 'post-command-hook)))))
962 (mapc 'funcall (nreverse commands))
964 ;; Delete the client if necessary.
967 ;; Client requested nowait; return immediately.
968 (server-log "Close nowait client" proc)
969 (server-delete-client proc))
970 ((and (not dontkill) (null buffers))
971 ;; This client is empty; get rid of it immediately.
972 (server-log "Close empty client" proc)
973 (server-delete-client proc)))
975 ((or isearch-mode (minibufferp))
977 ((and frame (null buffers))
978 (message "%s" (substitute-command-keys
979 "When done with this frame, type \\[delete-frame]")))
980 ((not (null buffers))
981 (server-switch-buffer (car buffers))
982 (run-hooks 'server-switch-hook)
984 (message "%s" (substitute-command-keys
985 "When done with a buffer, type \\[server-edit]")))))
986 (when (and frame (null tty-name))
987 (server-unselect-display frame)))
988 (error (server-return-error proc err))))
990 (defun server-return-error (proc err)
993 proc (concat "-error " (server-quote-arg
994 (error-message-string err))))
995 (server-log (error-message-string err) proc)
996 (delete-process proc)))
998 (defun server-goto-line-column (file-line-col)
999 "Move point to the position indicated in FILE-LINE-COL.
1000 FILE-LINE-COL should be a three-element list as described in
1001 `server-visit-files'."
1002 (goto-line (nth 1 file-line-col))
1003 (let ((column-number (nth 2 file-line-col)))
1004 (when (> column-number 0)
1005 (move-to-column (1- column-number)))))
1007 (defun server-visit-files (files proc &optional nowait)
1008 "Find FILES and return a list of buffers created.
1009 FILES is an alist whose elements are (FILENAME LINENUMBER COLUMNNUMBER).
1010 PROC is the client that requested this operation.
1011 NOWAIT non-nil means this client is not waiting for the results,
1012 so don't mark these buffers specially, just visit them normally."
1013 ;; Bind last-nonmenu-event to force use of keyboard, not mouse, for queries.
1014 (let ((last-nonmenu-event t) client-record)
1015 ;; Restore the current buffer afterward, but not using save-excursion,
1016 ;; because we don't want to save point in this buffer
1017 ;; if it happens to be one of those specified by the server.
1018 (save-current-buffer
1019 (dolist (file files)
1020 ;; If there is an existing buffer modified or the file is
1021 ;; modified, revert it. If there is an existing buffer with
1022 ;; deleted file, offer to write it.
1023 (let* ((minibuffer-auto-raise (or server-raise-frame
1024 minibuffer-auto-raise))
1026 (obuf (get-file-buffer filen)))
1027 (add-to-history 'file-name-history filen)
1028 (if (and obuf (set-buffer obuf))
1030 (cond ((file-exists-p filen)
1031 (when (not (verify-visited-file-modtime obuf))
1032 (revert-buffer t nil)))
1035 (concat "File no longer exists: " filen
1036 ", write buffer to file? "))
1037 (write-file filen))))
1038 (unless server-buffer-clients
1039 (setq server-existing-buffer t))
1040 (server-goto-line-column file))
1041 (set-buffer (find-file-noselect filen))
1042 (server-goto-line-column file)
1043 (run-hooks 'server-visit-hook)))
1045 ;; When the buffer is killed, inform the clients.
1046 (add-hook 'kill-buffer-hook 'server-kill-buffer nil t)
1047 (push proc server-buffer-clients))
1048 (push (current-buffer) client-record)))
1050 (process-put proc 'buffers
1051 (nconc (process-get proc 'buffers) client-record)))
1054 (defun server-buffer-done (buffer &optional for-killing)
1055 "Mark BUFFER as \"done\" for its client(s).
1056 This buries the buffer, then returns a list of the form (NEXT-BUFFER KILLED).
1057 NEXT-BUFFER is another server buffer, as a suggestion for what to select next,
1058 or nil. KILLED is t if we killed BUFFER (typically, because it was visiting
1060 FOR-KILLING if non-nil indicates that we are called from `kill-buffer'."
1061 (let ((next-buffer nil)
1063 (dolist (proc server-clients)
1064 (let ((buffers (process-get proc 'buffers)))
1066 (setq next-buffer (nth 1 (memq buffer buffers))))
1067 (when buffers ; Ignore bufferless clients.
1068 (setq buffers (delq buffer buffers))
1069 ;; Delete all dead buffers from PROC.
1072 (not (buffer-live-p b))
1073 (setq buffers (delq b buffers))))
1074 (process-put proc 'buffers buffers)
1075 ;; If client now has no pending buffers,
1076 ;; tell it that it is done, and forget it entirely.
1078 (server-log "Close" proc)
1079 (server-delete-client proc)))))
1080 (when (and (bufferp buffer) (buffer-name buffer))
1081 ;; We may or may not kill this buffer;
1082 ;; if we do, do not call server-buffer-done recursively
1083 ;; from kill-buffer-hook.
1084 (let ((server-kill-buffer-running t))
1085 (with-current-buffer buffer
1086 (setq server-buffer-clients nil)
1087 (run-hooks 'server-done-hook))
1088 ;; Notice whether server-done-hook killed the buffer.
1089 (if (null (buffer-name buffer))
1091 ;; Don't bother killing or burying the buffer
1092 ;; when we are called from kill-buffer.
1094 (when (and (not killed)
1095 server-kill-new-buffers
1096 (with-current-buffer buffer
1097 (not server-existing-buffer)))
1099 (bury-buffer buffer)
1100 (kill-buffer buffer))
1102 (if (server-temp-file-p buffer)
1104 (kill-buffer buffer)
1106 (bury-buffer buffer)))))))
1107 (list next-buffer killed)))
1109 (defun server-temp-file-p (&optional buffer)
1110 "Return non-nil if BUFFER contains a file considered temporary.
1111 These are files whose names suggest they are repeatedly
1112 reused to pass information to another program.
1114 The variable `server-temp-file-regexp' controls which filenames
1115 are considered temporary."
1116 (and (buffer-file-name buffer)
1117 (string-match server-temp-file-regexp (buffer-file-name buffer))))
1119 (defun server-done ()
1120 "Offer to save current buffer, mark it as \"done\" for clients.
1121 This kills or buries the buffer, then returns a list
1122 of the form (NEXT-BUFFER KILLED). NEXT-BUFFER is another server buffer,
1123 as a suggestion for what to select next, or nil.
1124 KILLED is t if we killed BUFFER, which happens if it was created
1125 specifically for the clients and did not exist before their request for it."
1126 (when server-buffer-clients
1127 (if (server-temp-file-p)
1128 ;; For a temp file, save, and do make a non-numeric backup
1129 ;; (unless make-backup-files is nil).
1130 (let ((version-control nil)
1131 (buffer-backed-up nil))
1133 (when (and (buffer-modified-p)
1135 (y-or-n-p (concat "Save file " buffer-file-name "? ")))
1137 (server-buffer-done (current-buffer))))
1139 ;; Ask before killing a server buffer.
1140 ;; It was suggested to release its client instead,
1141 ;; but I think that is dangerous--the client would proceed
1142 ;; using whatever is on disk in that file. -- rms.
1143 (defun server-kill-buffer-query-function ()
1144 "Ask before killing a server buffer."
1145 (or (not server-buffer-clients)
1147 (dolist (proc server-buffer-clients res)
1148 (when (and (memq proc server-clients)
1149 (eq (process-status proc) 'open))
1151 (yes-or-no-p (format "Buffer `%s' still has clients; kill it? "
1152 (buffer-name (current-buffer))))))
1154 (defun server-kill-emacs-query-function ()
1155 "Ask before exiting Emacs if it has live clients."
1156 (or (not server-clients)
1158 (dolist (proc server-clients live-client)
1159 (when (memq t (mapcar 'buffer-live-p (process-get
1161 (setq live-client t))))
1162 (yes-or-no-p "This Emacs session has clients; exit anyway? ")))
1164 (defvar server-kill-buffer-running nil
1165 "Non-nil while `server-kill-buffer' or `server-buffer-done' is running.")
1167 (defun server-kill-buffer ()
1168 "Remove the current buffer from its clients' buffer list.
1169 Designed to be added to `kill-buffer-hook'."
1170 ;; Prevent infinite recursion if user has made server-done-hook
1171 ;; call kill-buffer.
1172 (or server-kill-buffer-running
1173 (and server-buffer-clients
1174 (let ((server-kill-buffer-running t))
1175 (when server-process
1176 (server-buffer-done (current-buffer) t))))))
1178 (defun server-edit (&optional arg)
1179 "Switch to next server editing buffer; say \"Done\" for current buffer.
1180 If a server buffer is current, it is marked \"done\" and optionally saved.
1181 The buffer is also killed if it did not exist before the clients asked for it.
1182 When all of a client's buffers are marked as \"done\", the client is notified.
1184 Temporary files such as MH <draft> files are always saved and backed up,
1185 no questions asked. (The variable `make-backup-files', if nil, still
1186 inhibits a backup; you can set it locally in a particular buffer to
1187 prevent a backup for it.) The variable `server-temp-file-regexp' controls
1188 which filenames are considered temporary.
1190 If invoked with a prefix argument, or if there is no server process running,
1191 starts server process and that is all. Invoked by \\[server-edit]."
1195 (not server-process)
1196 (memq (process-status server-process) '(signal exit)))
1198 (server-clients (apply 'server-switch-buffer (server-done)))
1199 (t (message "No server editing buffers exist"))))
1201 (defun server-switch-buffer (&optional next-buffer killed-one)
1202 "Switch to another buffer, preferably one that has a client.
1203 Arg NEXT-BUFFER is a suggestion; if it is a live buffer, use it.
1205 KILLED-ONE is t in a recursive call if we have already killed one
1206 temp-file server buffer. This means we should avoid the final
1207 \"switch to some other buffer\" since we've already effectively
1209 (if (null next-buffer)
1211 (let ((rest server-clients))
1212 (while (and rest (not next-buffer))
1213 (let ((proc (car rest)))
1214 ;; Only look at frameless clients.
1215 (when (not (process-get proc 'frame))
1216 (setq next-buffer (car (process-get proc 'buffers))))
1217 (setq rest (cdr rest)))))
1218 (and next-buffer (server-switch-buffer next-buffer killed-one))
1219 (unless (or next-buffer killed-one (window-dedicated-p (selected-window)))
1220 ;; (switch-to-buffer (other-buffer))
1221 (message "No server buffers remain to edit")))
1222 (if (not (buffer-live-p next-buffer))
1223 ;; If NEXT-BUFFER is a dead buffer, remove the server records for it
1224 ;; and try the next surviving server buffer.
1225 (apply 'server-switch-buffer (server-buffer-done next-buffer))
1226 ;; OK, we know next-buffer is live, let's display and select it.
1227 (if (functionp server-window)
1228 (funcall server-window next-buffer)
1229 (let ((win (get-buffer-window next-buffer 0)))
1230 (if (and win (not server-window))
1231 ;; The buffer is already displayed: just reuse the window.
1234 (set-buffer next-buffer))
1235 ;; Otherwise, let's find an appropriate window.
1236 (cond ((window-live-p server-window)
1237 (select-window server-window))
1238 ((framep server-window)
1239 (unless (frame-live-p server-window)
1240 (setq server-window (make-frame)))
1241 (select-window (frame-selected-window server-window))))
1242 (when (window-minibuffer-p (selected-window))
1243 (select-window (next-window nil 'nomini 0)))
1244 ;; Move to a non-dedicated window, if we have one.
1245 (when (window-dedicated-p (selected-window))
1247 (get-window-with-predicate
1249 (and (not (window-dedicated-p w))
1250 (equal (frame-terminal (window-frame w))
1251 (frame-terminal (selected-frame)))))
1252 'nomini 'visible (selected-window))))
1254 (switch-to-buffer next-buffer)
1255 ;; After all the above, we might still have ended up with
1256 ;; a minibuffer/dedicated-window (if there's no other).
1257 (error (pop-to-buffer next-buffer)))))))
1258 (when server-raise-frame
1259 (select-frame-set-input-focus (window-frame (selected-window))))))
1262 (defun server-save-buffers-kill-terminal (proc &optional arg)
1263 ;; Called from save-buffers-kill-terminal in files.el.
1264 "Offer to save each buffer, then kill PROC.
1266 With prefix arg, silently save all file-visiting buffers, then kill.
1268 If emacsclient was started with a list of filenames to edit, then
1269 only these files will be asked to be saved."
1270 ;; save-buffers-kill-terminal occasionally calls us with proc set
1271 ;; to `nowait' (comes from the value of the `client' frame parameter).
1272 (when (processp proc)
1273 (let ((buffers (process-get proc 'buffers)))
1274 ;; If client is bufferless, emulate a normal Emacs session
1275 ;; exit and offer to save all buffers. Otherwise, offer to
1276 ;; save only the buffers belonging to the client.
1277 (save-some-buffers arg
1279 (lambda () (memq (current-buffer) buffers))
1281 (server-delete-client proc))))
1283 (define-key ctl-x-map "#" 'server-edit)
1285 (defun server-unload-function ()
1286 "Unload the server library."
1288 (substitute-key-definition 'server-edit nil ctl-x-map)
1289 (save-current-buffer
1290 (dolist (buffer (buffer-list))
1292 (remove-hook 'kill-buffer-hook 'server-kill-buffer t)))
1293 ;; continue standard unloading
1299 ;; arch-tag: 1f7ecb42-f00a-49f8-906d-61995d84c8d6
1300 ;;; server.el ends here