1 ;;; server.el --- Lisp code for GNU Emacs running as server process.
3 ;; Copyright (C) 1986, 87, 92, 94, 95, 96, 1997 Free Software Foundation, Inc.
5 ;; Author: William Sommerfeld <wesommer@athena.mit.edu>
9 ;; Changes by peck@sun.com and by rms.
11 ;; This file is part of GNU Emacs.
13 ;; GNU Emacs is free software; you can redistribute it and/or modify
14 ;; it under the terms of the GNU General Public License as published by
15 ;; the Free Software Foundation; either version 2, or (at your option)
18 ;; GNU Emacs is distributed in the hope that it will be useful,
19 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
20 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
21 ;; GNU General Public License for more details.
23 ;; You should have received a copy of the GNU General Public License
24 ;; along with GNU Emacs; see the file COPYING. If not, write to the
25 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
26 ;; Boston, MA 02111-1307, USA.
30 ;; This Lisp code is run in Emacs when it is to operate as
31 ;; a server for other processes.
33 ;; Load this library and do M-x server-edit to enable Emacs as a server.
34 ;; Emacs runs the program ../arch-lib/emacsserver as a subprocess
35 ;; for communication with clients. If there are no client buffers to edit,
36 ;; server-edit acts like (switch-to-buffer (other-buffer))
38 ;; When some other program runs "the editor" to edit a file,
39 ;; "the editor" can be the Emacs client program ../lib-src/emacsclient.
40 ;; This program transmits the file names to Emacs through
41 ;; the server subprocess, and Emacs visits them and lets you edit them.
43 ;; Note that any number of clients may dispatch files to emacs to be edited.
45 ;; When you finish editing a Server buffer, again call server-edit
46 ;; to mark that buffer as done for the client and switch to the next
47 ;; Server buffer. When all the buffers for a client have been edited
48 ;; and exited with server-edit, the client "editor" will return
49 ;; to the program that invoked it.
51 ;; Your editing commands and Emacs's display output go to and from
52 ;; the terminal in the usual way. Thus, server operation is possible
53 ;; only when Emacs can talk to the terminal at the time you invoke
54 ;; the client. This is possible in four cases:
56 ;; 1. On a window system, where Emacs runs in one window and the
57 ;; program that wants to use "the editor" runs in another.
59 ;; 2. On a multi-terminal system, where Emacs runs on one terminal and the
60 ;; program that wants to use "the editor" runs on another.
62 ;; 3. When the program that wants to use "the editor" is running
63 ;; as a subprocess of Emacs.
65 ;; 4. On a system with job control, when Emacs is suspended, the program
66 ;; that wants to use "the editor" will stop and display
67 ;; "Waiting for Emacs...". It can then be suspended, and Emacs can be
68 ;; brought into the foreground for editing. When done editing, Emacs is
69 ;; suspended again, and the client program is brought into the foreground.
71 ;; The buffer local variable "server-buffer-clients" lists
72 ;; the clients who are waiting for this buffer to be edited.
73 ;; The global variable "server-clients" lists all the waiting clients,
74 ;; and which files are yet to be edited for each.
79 "Emacs running as a server process."
82 (defcustom server-program
(expand-file-name "emacsserver" exec-directory
)
83 "*The program to use as the edit server."
87 (defcustom server-visit-hook nil
88 "*List of hooks to call when visiting a file for the Emacs server."
90 :type
'(repeat function
))
92 (defcustom server-switch-hook nil
93 "*List of hooks to call when switching to a buffer for the Emacs server."
95 :type
'(repeat function
))
97 (defcustom server-done-hook nil
98 "*List of hooks to call when done editing a buffer for the Emacs server."
100 :type
'(repeat function
))
102 (defvar server-process nil
103 "the current server process")
105 (defvar server-previous-string
"")
107 (defvar server-clients nil
108 "List of current server clients.
109 Each element is (CLIENTID BUFFERS...) where CLIENTID is a string
110 that can be given to the server process to identify a client.
111 When a buffer is marked as \"done\", it is removed from this list.")
113 (defvar server-buffer-clients nil
114 "List of clientids for clients requesting editing of current buffer.")
115 (make-variable-buffer-local 'server-buffer-clients
)
116 ;; Changing major modes should not erase this local.
117 (put 'server-buffer-clients
'permanent-local t
)
119 (defvar server-window nil
120 "*The window to use for selecting Emacs server buffers.
121 If nil, use the selected window.
122 If it is a frame, use the frame's selected window.")
124 (defcustom server-temp-file-regexp
"^/tmp/Re\\|/draft$"
125 "*Regexp which should match filenames of temporary files
126 which are deleted and reused after each edit
127 by the programs that invoke the emacs server."
131 (or (assq 'server-buffer-clients minor-mode-alist
)
132 (setq minor-mode-alist
(cons '(server-buffer-clients " Server") minor-mode-alist
)))
134 ;; If a *server* buffer exists,
135 ;; write STRING to it for logging purposes.
136 (defun server-log (string)
137 (if (get-buffer "*server*")
139 (set-buffer "*server*")
140 (goto-char (point-max))
141 (insert (current-time-string) " " string
)
142 (or (bolp) (newline)))))
144 (defun server-sentinel (proc msg
)
145 (cond ((eq (process-status proc
) 'exit
)
146 (server-log (message "Server subprocess exited")))
147 ((eq (process-status proc
) 'signal
)
148 (server-log (message "Server subprocess killed")))))
151 (defun server-start (&optional leave-dead
)
152 "Allow this Emacs process to be a server for client processes.
153 This starts a server communications subprocess through which
154 client \"editors\" can send your editing commands to this Emacs job.
155 To use the server, set up the program `emacsclient' in the
156 Emacs distribution as your standard \"editor\".
158 Prefix arg means just kill any existing server communications subprocess."
163 (set-process-sentinel server-process nil
)
164 (condition-case () (delete-process server-process
) (error nil
))))
165 ;; Delete the socket files made by previous server invocations.
166 (let* ((sysname (system-name))
167 (dot-index (string-match "\\." sysname
)))
169 (delete-file (format "~/.emacs-server-%s" sysname
))
172 (delete-file (format "/tmp/esrv%d-%s" (user-uid) sysname
))
174 ;; In case the server file name was made with a domainless hostname,
175 ;; try deleting that name too.
177 (let ((shortname (substring sysname
0 dot-index
)))
179 (delete-file (format "~/.emacs-server-%s" shortname
))
182 (delete-file (format "/tmp/esrv%d-%s" (user-uid) shortname
))
184 ;; If this Emacs already had a server, clear out associated status.
185 (while server-clients
186 (let ((buffer (nth 1 (car server-clients
))))
187 (server-buffer-done buffer
)))
191 (server-log (message "Restarting server")))
192 ;; Using a pty is wasteful, and the separate session causes
193 ;; annoyance sometimes (some systems kill idle sessions).
194 (let ((process-connection-type nil
))
195 (setq server-process
(start-process "server" nil server-program
)))
196 (set-process-sentinel server-process
'server-sentinel
)
197 (set-process-filter server-process
'server-process-filter
)
198 (process-kill-without-query server-process
)))
200 ;Process a request from the server to edit some files.
201 ;Format of STRING is "Client: CLIENTID PATH PATH PATH... \n"
202 (defun server-process-filter (proc string
)
204 (setq string
(concat server-previous-string string
))
205 ;; If the input is multiple lines,
206 ;; process each line individually.
207 (while (string-match "\n" string
)
208 (let ((request (substring string
0 (match-beginning 0)))
212 ;; Remove this line from STRING.
213 (setq string
(substring string
(match-end 0)))
214 (if (string-match "^Error: " request
)
215 (message "Server error: %s" (substring request
(match-end 0)))
216 (if (string-match "^Client: " request
)
218 (setq request
(substring request
(match-end 0)))
219 (setq client
(list (substring request
0 (string-match " " request
))))
220 (setq request
(substring request
(match-end 0)))
221 (while (string-match "[^ ]+ " request
)
223 (substring request
(match-beginning 0) (1- (match-end 0))))
225 (setq request
(substring request
(match-end 0)))
226 (if (string-match "\\`-nowait" arg
)
228 (if (string-match "\\`\\+[0-9]+\\'" arg
)
229 ;; ARG is a line number option.
230 (setq lineno
(read (substring arg
1)))
231 ;; ARG is a file name.
232 ;; Collapse multiple slashes to single slashes.
233 (setq arg
(command-line-normalize-file-name arg
))
234 ;; Undo the quoting that emacsclient does
235 ;; for certain special characters.
236 (while (string-match "&." arg pos
)
237 (setq pos
(1+ (match-beginning 0)))
238 (let ((nextchar (aref arg pos
)))
239 (cond ((= nextchar ?
&)
240 (setq arg
(replace-match "&" t t arg
)))
242 (setq arg
(replace-match "-" t t arg
)))
244 (setq arg
(replace-match " " t t arg
))))))
246 (cons (list arg lineno
)
249 (server-visit-files files client nowait
)
250 ;; CLIENT is now a list (CLIENTNUM BUFFERS...)
252 (setq server-clients
(cons client server-clients
)))
253 (server-switch-buffer (nth 1 client
))
254 (run-hooks 'server-switch-hook
)
255 (message (substitute-command-keys
256 "When done with a buffer, type \\[server-edit]")))))))
257 ;; Save for later any partial line that remains.
258 (setq server-previous-string string
))
260 (defun server-visit-files (files client
&optional nowait
)
261 "Finds FILES and returns the list CLIENT with the buffers nconc'd.
262 FILES is an alist whose elements are (FILENAME LINENUMBER).
263 NOWAIT non-nil means this client is not waiting for the results,
264 so don't mark these buffers specially, just visit them normally."
265 ;; Bind last-nonmenu-event to force use of keyboard, not mouse, for queries.
266 (let (client-record (last-nonmenu-event t
) (obuf (current-buffer)))
267 ;; Restore the current buffer afterward, but not using save-excursion,
268 ;; because we don't want to save point in this buffer
269 ;; if it happens to be one of those specified by the server.
272 ;; If there is an existing buffer modified or the file is modified,
274 ;; If there is an existing buffer with deleted file, offer to write it.
275 (let* ((filen (car (car files
)))
276 (obuf (get-file-buffer filen
)))
277 (if (and obuf
(set-buffer obuf
))
278 (if (file-exists-p filen
)
279 (if (or (not (verify-visited-file-modtime obuf
))
280 (buffer-modified-p obuf
))
281 (revert-buffer t nil
))
283 (concat "File no longer exists: "
285 ", write buffer to file? "))
287 (set-buffer (find-file-noselect filen
))
288 (run-hooks 'server-visit-hook
)))
289 (goto-line (nth 1 (car files
)))
291 (setq server-buffer-clients
292 (cons (car client
) server-buffer-clients
)))
293 (setq client-record
(cons (current-buffer) client-record
))
294 (setq files
(cdr files
)))
296 (nconc client client-record
)))
298 (defun server-buffer-done (buffer &optional for-killing
)
299 "Mark BUFFER as \"done\" for its client(s).
300 This buries the buffer, then returns a list of the form (NEXT-BUFFER KILLED).
301 NEXT-BUFFER is another server buffer, as a suggestion for what to select next,
302 or nil. KILLED is t if we killed BUFFER (because it was a temp file)."
303 (let ((running (eq (process-status server-process
) 'run
))
307 (old-clients server-clients
))
309 (let ((client (car old-clients
)))
311 (setq next-buffer
(nth 1 (memq buffer client
))))
313 ;; Delete all dead buffers from CLIENT.
316 (and (bufferp (car tail
))
317 (null (buffer-name (car tail
)))
318 (delq (car tail
) client
))
319 (setq tail
(cdr tail
))))
320 ;; If client now has no pending buffers,
321 ;; tell it that it is done, and forget it entirely.
325 ;; Don't send emacsserver two commands in close succession.
326 ;; It cannot handle that.
327 (or first
(sit-for 1))
329 (send-string server-process
330 (format "Close: %s Done\n" (car client
)))
331 (server-log (format "Close: %s Done\n" (car client
)))))
332 (setq server-clients
(delq client server-clients
))))
333 (setq old-clients
(cdr old-clients
)))
334 (if (and (bufferp buffer
) (buffer-name buffer
))
338 (setq server-buffer-clients nil
)
339 (run-hooks 'server-done-hook
))
341 (if (server-temp-file-p buffer
)
342 (progn (kill-buffer buffer
)
344 (bury-buffer buffer
)))))
345 (list next-buffer killed
)))
347 (defun server-temp-file-p (buffer)
348 "Return non-nil if BUFFER contains a file considered temporary.
349 These are files whose names suggest they are repeatedly
350 reused to pass information to another program.
352 The variable `server-temp-file-regexp' controls which filenames
353 are considered temporary."
354 (and (buffer-file-name buffer
)
355 (string-match server-temp-file-regexp
(buffer-file-name buffer
))))
357 (defun server-done ()
358 "Offer to save current buffer, mark it as \"done\" for clients.
359 This buries the buffer, then returns a list of the form (NEXT-BUFFER KILLED).
360 NEXT-BUFFER is another server buffer, as a suggestion for what to select next,
361 or nil. KILLED is t if we killed the BUFFER (because it was a temp file)."
362 (let ((buffer (current-buffer)))
363 (if server-buffer-clients
365 (if (server-temp-file-p buffer
)
366 ;; For a temp file, save, and do make a non-numeric backup
367 ;; (unless make-backup-files is nil).
368 (let ((version-control nil
)
369 (buffer-backed-up nil
))
371 (if (and (buffer-modified-p)
373 (y-or-n-p (concat "Save file " buffer-file-name
"? ")))
374 (save-buffer buffer
)))
375 (server-buffer-done buffer
)))))
377 ;; Ask before killing a server buffer.
378 ;; It was suggested to release its client instead,
379 ;; but I think that is dangerous--the client would proceed
380 ;; using whatever is on disk in that file. -- rms.
381 (defun server-kill-buffer-query-function ()
382 (or (not server-buffer-clients
)
383 (yes-or-no-p (format "Buffer `%s' still has clients; kill it? "
384 (buffer-name (current-buffer))))))
386 (add-hook 'kill-buffer-query-functions
387 'server-kill-buffer-query-function
)
389 (defun server-kill-emacs-query-function ()
391 (tail server-clients
))
392 ;; See if any clients have any buffers that are still alive.
394 (if (memq t
(mapcar 'stringp
(mapcar 'buffer-name
(cdr (car tail
)))))
395 (setq live-client t
))
396 (setq tail
(cdr tail
)))
397 (or (not live-client
)
398 (yes-or-no-p "Server buffers still have clients; exit anyway? "))))
400 (add-hook 'kill-emacs-query-functions
'server-kill-emacs-query-function
)
402 (defvar server-kill-buffer-running nil
403 "Non-nil while `server-kill-buffer' is running.")
405 ;; When a buffer is killed, inform the clients.
406 (add-hook 'kill-buffer-hook
'server-kill-buffer
)
407 (defun server-kill-buffer ()
408 ;; Prevent infinite recursion if user has made server-done-hook
410 (or server-kill-buffer-running
411 (let ((server-kill-buffer-running t
))
413 (server-buffer-done (current-buffer) t
)))))
415 (defun server-edit (&optional arg
)
416 "Switch to next server editing buffer; say \"Done\" for current buffer.
417 If a server buffer is current, it is marked \"done\" and optionally saved.
418 When all of a client's buffers are marked as \"done\", the client is notified.
420 Temporary files such as MH <draft> files are always saved and backed up,
421 no questions asked. (The variable `make-backup-files', if nil, still
422 inhibits a backup; you can set it locally in a particular buffer to
423 prevent a backup for it.) The variable `server-temp-file-regexp' controls
424 which filenames are considered temporary.
426 If invoked with a prefix argument, or if there is no server process running,
427 starts server process and that is all. Invoked by \\[server-edit]."
431 (memq (process-status server-process
) '(signal exit
)))
433 (apply 'server-switch-buffer
(server-done))))
435 (defun server-switch-buffer (&optional next-buffer killed-one
)
436 "Switch to another buffer, preferably one that has a client.
437 Arg NEXT-BUFFER is a suggestion; if it is a live buffer, use it."
438 ;; KILLED-ONE is t in a recursive call
439 ;; if we have already killed one temp-file server buffer.
440 ;; This means we should avoid the final "switch to some other buffer"
441 ;; since we've already effectively done that.
442 (cond ((and (windowp server-window
)
443 (window-live-p server-window
))
444 (select-window server-window
))
445 ((framep server-window
)
446 (if (not (frame-live-p server-window
))
447 (setq server-window
(make-frame)))
448 (select-window (frame-selected-window server-window
))))
449 (if (window-minibuffer-p (selected-window))
450 (select-window (next-window nil
'nomini
0)))
451 ;; Move to a non-dedicated window, if we have one.
452 (let ((last-window (previous-window nil
'nomini
0)))
453 (while (and (window-dedicated-p (selected-window))
454 (not (eq last-window
(selected-window))))
455 (select-window (next-window nil
'nomini
0))))
456 (set-window-dedicated-p (selected-window) nil
)
458 (if (and (bufferp next-buffer
)
459 (buffer-name next-buffer
))
460 (switch-to-buffer next-buffer
)
461 ;; If NEXT-BUFFER is a dead buffer,
462 ;; remove the server records for it
463 ;; and try the next surviving server buffer.
464 (apply 'server-switch-buffer
465 (server-buffer-done next-buffer
)))
467 (server-switch-buffer (nth 1 (car server-clients
)) killed-one
)
469 (switch-to-buffer (other-buffer))))))
471 (global-set-key "\C-x#" 'server-edit
)
475 ;;; server.el ends here