1 ;;; server.el --- Lisp code for GNU Emacs running as server process
3 ;; Copyright (C) 1986, 87, 92, 94, 95, 96, 97, 98, 99, 2000, 2001
4 ;; Free Software Foundation, Inc.
6 ;; Author: William Sommerfeld <wesommer@athena.mit.edu>
10 ;; Changes by peck@sun.com and by rms.
12 ;; This file is part of GNU Emacs.
14 ;; GNU Emacs is free software; you can redistribute it and/or modify
15 ;; it under the terms of the GNU General Public License as published by
16 ;; the Free Software Foundation; either version 2, or (at your option)
19 ;; GNU Emacs is distributed in the hope that it will be useful,
20 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
21 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 ;; GNU General Public License for more details.
24 ;; You should have received a copy of the GNU General Public License
25 ;; along with GNU Emacs; see the file COPYING. If not, write to the
26 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
27 ;; Boston, MA 02111-1307, USA.
31 ;; This Lisp code is run in Emacs when it is to operate as
32 ;; a server for other processes.
34 ;; Load this library and do M-x server-edit to enable Emacs as a server.
35 ;; Emacs runs the program ../arch-lib/emacsserver as a subprocess
36 ;; for communication with clients. If there are no client buffers to edit,
37 ;; server-edit acts like (switch-to-buffer (other-buffer))
39 ;; When some other program runs "the editor" to edit a file,
40 ;; "the editor" can be the Emacs client program ../lib-src/emacsclient.
41 ;; This program transmits the file names to Emacs through
42 ;; the server subprocess, and Emacs visits them and lets you edit them.
44 ;; Note that any number of clients may dispatch files to emacs to be edited.
46 ;; When you finish editing a Server buffer, again call server-edit
47 ;; to mark that buffer as done for the client and switch to the next
48 ;; Server buffer. When all the buffers for a client have been edited
49 ;; and exited with server-edit, the client "editor" will return
50 ;; to the program that invoked it.
52 ;; Your editing commands and Emacs's display output go to and from
53 ;; the terminal in the usual way. Thus, server operation is possible
54 ;; only when Emacs can talk to the terminal at the time you invoke
55 ;; the client. This is possible in four cases:
57 ;; 1. On a window system, where Emacs runs in one window and the
58 ;; program that wants to use "the editor" runs in another.
60 ;; 2. On a multi-terminal system, where Emacs runs on one terminal and the
61 ;; program that wants to use "the editor" runs on another.
63 ;; 3. When the program that wants to use "the editor" is running
64 ;; as a subprocess of Emacs.
66 ;; 4. On a system with job control, when Emacs is suspended, the program
67 ;; that wants to use "the editor" will stop and display
68 ;; "Waiting for Emacs...". It can then be suspended, and Emacs can be
69 ;; brought into the foreground for editing. When done editing, Emacs is
70 ;; suspended again, and the client program is brought into the foreground.
72 ;; The buffer local variable "server-buffer-clients" lists
73 ;; the clients who are waiting for this buffer to be edited.
74 ;; The global variable "server-clients" lists all the waiting clients,
75 ;; and which files are yet to be edited for each.
80 "Emacs running as a server process."
83 (defcustom server-program
(expand-file-name "emacsserver" exec-directory
)
84 "*The program to use as the edit server."
88 (defcustom server-visit-hook nil
89 "*List of hooks to call when visiting a file for the Emacs server."
91 :type
'(repeat function
))
93 (defcustom server-switch-hook nil
94 "*List of hooks to call when switching to a buffer for the Emacs server."
96 :type
'(repeat function
))
98 (defcustom server-done-hook nil
99 "*List of hooks to call when done editing a buffer for the Emacs server."
101 :type
'(repeat function
))
103 (defvar server-process nil
104 "The current server process")
106 (defvar server-previous-string
"")
108 (defvar server-clients nil
109 "List of current server clients.
110 Each element is (CLIENTID BUFFERS...) where CLIENTID is a string
111 that can be given to the server process to identify a client.
112 When a buffer is marked as \"done\", it is removed from this list.")
114 (defvar server-buffer-clients nil
115 "List of client ids for clients requesting editing of current buffer.")
116 (make-variable-buffer-local 'server-buffer-clients
)
117 ;; Changing major modes should not erase this local.
118 (put 'server-buffer-clients
'permanent-local t
)
120 (defvar server-window nil
121 "*The window to use for selecting Emacs server buffers.
122 If nil, use the selected window.
123 If it is a frame, use the frame's selected window.")
125 (defcustom server-temp-file-regexp
"^/tmp/Re\\|/draft$"
126 "*Regexp which should match filenames of temporary files
127 which are deleted and reused after each edit
128 by the programs that invoke the Emacs server."
132 (defcustom server-kill-new-buffers t
133 "*Whether to kill buffers when done with them.
134 If non-nil, kill a buffer unless it already existed before editing
135 it with Emacs server. If nil, kill only buffers as specified by
136 `server-temp-file-regexp'.
137 Please note that only buffers are killed that still have a client,
138 i.e. buffers visited which \"emacsclient --no-wait\" are never killed in
144 (or (assq 'server-buffer-clients minor-mode-alist
)
145 (setq minor-mode-alist
(cons '(server-buffer-clients " Server") minor-mode-alist
)))
147 (defvar server-existing-buffer nil
148 "Non-nil means a server buffer existed before visiting a file.")
149 (make-variable-buffer-local 'server-existing-buffer
)
151 ;; If a *server* buffer exists,
152 ;; write STRING to it for logging purposes.
153 (defun server-log (string)
154 (if (get-buffer "*server*")
156 (set-buffer "*server*")
157 (goto-char (point-max))
158 (insert (current-time-string) " " string
)
159 (or (bolp) (newline)))))
161 (defun server-sentinel (proc msg
)
162 (cond ((eq (process-status proc
) 'exit
)
163 (server-log (message "Server subprocess exited")))
164 ((eq (process-status proc
) 'signal
)
165 (server-log (message "Server subprocess killed")))))
168 (defun server-start (&optional leave-dead
)
169 "Allow this Emacs process to be a server for client processes.
170 This starts a server communications subprocess through which
171 client \"editors\" can send your editing commands to this Emacs job.
172 To use the server, set up the program `emacsclient' in the
173 Emacs distribution as your standard \"editor\".
175 Prefix arg means just kill any existing server communications subprocess."
180 (set-process-sentinel server-process nil
)
181 (condition-case () (delete-process server-process
) (error nil
))))
182 ;; Delete the socket files made by previous server invocations.
183 (let* ((sysname (system-name))
184 (dot-index (string-match "\\." sysname
)))
186 (delete-file (format "~/.emacs-server-%s" sysname
))
189 (delete-file (format "/tmp/esrv%d-%s" (user-uid) sysname
))
191 ;; In case the server file name was made with a domainless hostname,
192 ;; try deleting that name too.
194 (let ((shortname (substring sysname
0 dot-index
)))
196 (delete-file (format "~/.emacs-server-%s" shortname
))
199 (delete-file (format "/tmp/esrv%d-%s" (user-uid) shortname
))
201 ;; If this Emacs already had a server, clear out associated status.
202 (while server-clients
203 (let ((buffer (nth 1 (car server-clients
))))
204 (server-buffer-done buffer
)))
208 (server-log (message "Restarting server")))
209 ;; Using a pty is wasteful, and the separate session causes
210 ;; annoyance sometimes (some systems kill idle sessions).
211 (let ((process-connection-type nil
))
212 (setq server-process
(start-process "server" nil server-program
)))
213 (set-process-sentinel server-process
'server-sentinel
)
214 (set-process-filter server-process
'server-process-filter
)
215 ;; We must receive file names without being decoded. Those are
216 ;; decoded by server-process-filter accoding to
217 ;; file-name-coding-system.
218 (set-process-coding-system server-process
'raw-text
'raw-text
)
219 (process-kill-without-query server-process
)))
221 ;Process a request from the server to edit some files.
222 ;Format of STRING is "Client: CLIENTID PATH PATH PATH... \n"
223 (defun server-process-filter (proc string
)
225 (setq string
(concat server-previous-string string
))
226 ;; If the input is multiple lines,
227 ;; process each line individually.
228 (while (string-match "\n" string
)
229 (let ((request (substring string
0 (match-beginning 0)))
230 (coding-system (and default-enable-multibyte-characters
231 (or file-name-coding-system
232 default-file-name-coding-system
)))
237 ;; Remove this line from STRING.
238 (setq string
(substring string
(match-end 0)))
239 (if (string-match "^Error: " request
)
240 (message "Server error: %s" (substring request
(match-end 0)))
241 (if (string-match "^Client: " request
)
243 (setq request
(substring request
(match-end 0)))
244 (setq client
(list (substring request
0 (string-match " " request
))))
245 (setq request
(substring request
(match-end 0)))
246 (while (string-match "[^ ]+ " request
)
248 (substring request
(match-beginning 0) (1- (match-end 0))))
250 (setq request
(substring request
(match-end 0)))
251 (if (string-match "\\`-nowait" arg
)
254 ;; ARG is a line number option.
255 ((string-match "\\`\\+[0-9]+\\'" arg
)
256 (setq lineno
(string-to-int (substring arg
1))))
257 ;; ARG is line number:column option.
258 ((string-match "\\`+\\([0-9]+\\):\\([0-9]+\\)\\'" arg
)
259 (setq lineno
(string-to-int (match-string 1 arg
))
260 columnno
(string-to-int (match-string 2 arg
))))
262 ;; ARG is a file name.
263 ;; Collapse multiple slashes to single slashes.
264 (setq arg
(command-line-normalize-file-name arg
))
265 ;; Undo the quoting that emacsclient does
266 ;; for certain special characters.
267 (while (string-match "&." arg pos
)
268 (setq pos
(1+ (match-beginning 0)))
269 (let ((nextchar (aref arg pos
)))
270 (cond ((= nextchar ?
&)
271 (setq arg
(replace-match "&" t t arg
)))
273 (setq arg
(replace-match "-" t t arg
)))
275 (setq arg
(replace-match " " t t arg
))))))
276 ;; Now decode the file name if necessary.
278 (setq arg
(decode-coding-string arg coding-system
)))
280 (cons (list arg lineno columnno
)
283 (setq columnno
0))))))
284 (server-visit-files files client nowait
)
285 ;; CLIENT is now a list (CLIENTNUM BUFFERS...)
286 (if (null (cdr client
))
287 ;; This client is empty; get rid of it immediately.
289 (send-string server-process
290 (format "Close: %s Done\n" (car client
)))
291 (server-log (format "Close empty client: %s Done\n" (car client
))))
292 ;; We visited some buffer for this client.
294 (setq server-clients
(cons client server-clients
)))
295 (server-switch-buffer (nth 1 client
))
296 (run-hooks 'server-switch-hook
)
297 (message (substitute-command-keys
298 "When done with a buffer, type \\[server-edit]"))))))))
299 ;; Save for later any partial line that remains.
300 (setq server-previous-string string
))
302 (defun server-visit-files (files client
&optional nowait
)
303 "Finds FILES and returns the list CLIENT with the buffers nconc'd.
304 FILES is an alist whose elements are (FILENAME LINENUMBER COLUMNNUMBER).
305 NOWAIT non-nil means this client is not waiting for the results,
306 so don't mark these buffers specially, just visit them normally."
307 ;; Bind last-nonmenu-event to force use of keyboard, not mouse, for queries.
308 (let (client-record (last-nonmenu-event t
) (obuf (current-buffer)))
309 ;; Restore the current buffer afterward, but not using save-excursion,
310 ;; because we don't want to save point in this buffer
311 ;; if it happens to be one of those specified by the server.
314 ;; If there is an existing buffer modified or the file is
315 ;; modified, revert it. If there is an existing buffer with
316 ;; deleted file, offer to write it.
317 (let* ((filen (car (car files
)))
318 (obuf (get-file-buffer filen
)))
319 (push filen file-name-history
)
320 (if (and obuf
(set-buffer obuf
))
322 (cond ((file-exists-p filen
)
323 (if (or (not (verify-visited-file-modtime obuf
))
324 (buffer-modified-p obuf
))
325 (revert-buffer t nil
)))
328 (concat "File no longer exists: "
330 ", write buffer to file? "))
331 (write-file filen
))))
332 (setq server-existing-buffer t
)
333 (goto-line (nth 1 (car files
))))
334 (set-buffer (find-file-noselect filen
))
335 (goto-line (nth 1 (car files
)))
336 (let ((column-number (nth 2 (car files
))))
337 (when (> column-number
0)
338 (move-to-column (1- column-number
))))
339 (run-hooks 'server-visit-hook
)))
341 (setq server-buffer-clients
342 (cons (car client
) server-buffer-clients
)))
343 (setq client-record
(cons (current-buffer) client-record
))
344 (setq files
(cdr files
)))
346 (nconc client client-record
)))
348 (defun server-buffer-done (buffer &optional for-killing
)
349 "Mark BUFFER as \"done\" for its client(s).
350 This buries the buffer, then returns a list of the form (NEXT-BUFFER KILLED).
351 NEXT-BUFFER is another server buffer, as a suggestion for what to select next,
352 or nil. KILLED is t if we killed BUFFER
353 \(typically, because it was visiting a temp file)."
354 (let ((running (eq (process-status server-process
) 'run
))
358 (old-clients server-clients
))
360 (let ((client (car old-clients
)))
362 (setq next-buffer
(nth 1 (memq buffer client
))))
364 ;; Delete all dead buffers from CLIENT.
367 (and (bufferp (car tail
))
368 (null (buffer-name (car tail
)))
369 (delq (car tail
) client
))
370 (setq tail
(cdr tail
))))
371 ;; If client now has no pending buffers,
372 ;; tell it that it is done, and forget it entirely.
376 ;; Don't send emacsserver two commands in close succession.
377 ;; It cannot handle that.
378 (or first
(sit-for 1))
380 (send-string server-process
381 (format "Close: %s Done\n" (car client
)))
382 (server-log (format "Close: %s Done\n" (car client
)))))
383 (setq server-clients
(delq client server-clients
))))
384 (setq old-clients
(cdr old-clients
)))
385 (if (and (bufferp buffer
) (buffer-name buffer
))
386 ;; We may or may not kill this buffer;
387 ;; if we do, do not call server-buffer-done recursively
388 ;; from kill-buffer-hook.
389 (let ((server-kill-buffer-running t
))
392 (setq server-buffer-clients nil
)
393 (run-hooks 'server-done-hook
))
394 ;; Notice whether server-done-hook killed the buffer.
395 (if (null (buffer-name buffer
))
397 ;; Don't bother killing or burying the buffer
398 ;; when we are called from kill-buffer.
400 (when (and (not killed
)
401 server-kill-new-buffers
402 (with-current-buffer buffer
403 (not server-existing-buffer
)))
406 (kill-buffer buffer
))
408 (if (server-temp-file-p buffer
)
412 (bury-buffer buffer
)))))))
413 (list next-buffer killed
)))
415 (defun server-temp-file-p (buffer)
416 "Return non-nil if BUFFER contains a file considered temporary.
417 These are files whose names suggest they are repeatedly
418 reused to pass information to another program.
420 The variable `server-temp-file-regexp' controls which filenames
421 are considered temporary."
422 (and (buffer-file-name buffer
)
423 (string-match server-temp-file-regexp
(buffer-file-name buffer
))))
425 (defun server-done ()
426 "Offer to save current buffer, mark it as \"done\" for clients.
427 This buries the buffer, then returns a list of the form (NEXT-BUFFER KILLED).
428 NEXT-BUFFER is another server buffer, as a suggestion for what to select next,
429 or nil. KILLED is t if we killed BUFFER
430 \(typically, because it was visiting a temp file)."
431 (let ((buffer (current-buffer)))
432 (if server-buffer-clients
434 (if (server-temp-file-p buffer
)
435 ;; For a temp file, save, and do make a non-numeric backup
436 ;; (unless make-backup-files is nil).
437 (let ((version-control nil
)
438 (buffer-backed-up nil
))
440 (if (and (buffer-modified-p)
442 (y-or-n-p (concat "Save file " buffer-file-name
"? ")))
443 (save-buffer buffer
)))
444 (server-buffer-done buffer
)))))
446 ;; Ask before killing a server buffer.
447 ;; It was suggested to release its client instead,
448 ;; but I think that is dangerous--the client would proceed
449 ;; using whatever is on disk in that file. -- rms.
450 (defun server-kill-buffer-query-function ()
451 (or (not server-buffer-clients
)
452 (yes-or-no-p (format "Buffer `%s' still has clients; kill it? "
453 (buffer-name (current-buffer))))))
455 (add-hook 'kill-buffer-query-functions
456 'server-kill-buffer-query-function
)
458 (defun server-kill-emacs-query-function ()
460 (tail server-clients
))
461 ;; See if any clients have any buffers that are still alive.
463 (if (memq t
(mapcar 'stringp
(mapcar 'buffer-name
(cdr (car tail
)))))
464 (setq live-client t
))
465 (setq tail
(cdr tail
)))
466 (or (not live-client
)
467 (yes-or-no-p "Server buffers still have clients; exit anyway? "))))
469 (add-hook 'kill-emacs-query-functions
'server-kill-emacs-query-function
)
471 (defvar server-kill-buffer-running nil
472 "Non-nil while `server-kill-buffer' or `server-buffer-done' is running.")
474 ;; When a buffer is killed, inform the clients.
475 (add-hook 'kill-buffer-hook
'server-kill-buffer
)
476 (defun server-kill-buffer ()
477 ;; Prevent infinite recursion if user has made server-done-hook
479 (or server-kill-buffer-running
480 (and server-buffer-clients
481 (let ((server-kill-buffer-running t
))
483 (server-buffer-done (current-buffer) t
))))))
485 (defun server-edit (&optional arg
)
486 "Switch to next server editing buffer; say \"Done\" for current buffer.
487 If a server buffer is current, it is marked \"done\" and optionally saved.
488 When all of a client's buffers are marked as \"done\", the client is notified.
490 Temporary files such as MH <draft> files are always saved and backed up,
491 no questions asked. (The variable `make-backup-files', if nil, still
492 inhibits a backup; you can set it locally in a particular buffer to
493 prevent a backup for it.) The variable `server-temp-file-regexp' controls
494 which filenames are considered temporary.
496 If invoked with a prefix argument, or if there is no server process running,
497 starts server process and that is all. Invoked by \\[server-edit]."
501 (memq (process-status server-process
) '(signal exit
)))
503 (apply 'server-switch-buffer
(server-done))))
505 (defun server-switch-buffer (&optional next-buffer killed-one
)
506 "Switch to another buffer, preferably one that has a client.
507 Arg NEXT-BUFFER is a suggestion; if it is a live buffer, use it."
508 ;; KILLED-ONE is t in a recursive call
509 ;; if we have already killed one temp-file server buffer.
510 ;; This means we should avoid the final "switch to some other buffer"
511 ;; since we've already effectively done that.
512 (cond ((and (windowp server-window
)
513 (window-live-p server-window
))
514 (select-window server-window
))
515 ((framep server-window
)
516 (if (not (frame-live-p server-window
))
517 (setq server-window
(make-frame)))
518 (select-window (frame-selected-window server-window
))))
519 (if (window-minibuffer-p (selected-window))
520 (select-window (next-window nil
'nomini
0)))
521 ;; Move to a non-dedicated window, if we have one.
522 (when (window-dedicated-p (selected-window))
523 (select-window (get-window-with-predicate
524 (lambda (w) (not (window-dedicated-p w
)))
525 'nomini
'visible
(selected-window))))
526 (set-window-dedicated-p (selected-window) nil
)
528 (if (and (bufferp next-buffer
)
529 (buffer-name next-buffer
))
530 (switch-to-buffer next-buffer
)
531 ;; If NEXT-BUFFER is a dead buffer,
532 ;; remove the server records for it
533 ;; and try the next surviving server buffer.
534 (apply 'server-switch-buffer
535 (server-buffer-done next-buffer
)))
537 (server-switch-buffer (nth 1 (car server-clients
)) killed-one
)
539 (switch-to-buffer (other-buffer))))))
541 (global-set-key "\C-x#" 'server-edit
)
545 ;;; server.el ends here