1 ;;; server.el --- Lisp code for GNU Emacs running as server process.
3 ;; Copyright (C) 1986, 1987, 1992, 1994, 1995 Free Software Foundation, Inc.
5 ;; Author: William Sommerfeld <wesommer@athena.mit.edu>
8 ;; Changes by peck@sun.com and by rms.
10 ;; This file is part of GNU Emacs.
12 ;; GNU Emacs is free software; you can redistribute it and/or modify
13 ;; it under the terms of the GNU General Public License as published by
14 ;; the Free Software Foundation; either version 2, or (at your option)
17 ;; GNU Emacs is distributed in the hope that it will be useful,
18 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
19 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 ;; GNU General Public License for more details.
22 ;; You should have received a copy of the GNU General Public License
23 ;; along with GNU Emacs; see the file COPYING. If not, write to the
24 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
25 ;; Boston, MA 02111-1307, USA.
29 ;; This Lisp code is run in Emacs when it is to operate as
30 ;; a server for other processes.
32 ;; Load this library and do M-x server-edit to enable Emacs as a server.
33 ;; Emacs runs the program ../arch-lib/emacsserver as a subprocess
34 ;; for communication with clients. If there are no client buffers to edit,
35 ;; server-edit acts like (switch-to-buffer (other-buffer))
37 ;; When some other program runs "the editor" to edit a file,
38 ;; "the editor" can be the Emacs client program ../lib-src/emacsclient.
39 ;; This program transmits the file names to Emacs through
40 ;; the server subprocess, and Emacs visits them and lets you edit them.
42 ;; Note that any number of clients may dispatch files to emacs to be edited.
44 ;; When you finish editing a Server buffer, again call server-edit
45 ;; to mark that buffer as done for the client and switch to the next
46 ;; Server buffer. When all the buffers for a client have been edited
47 ;; and exited with server-edit, the client "editor" will return
48 ;; to the program that invoked it.
50 ;; Your editing commands and Emacs's display output go to and from
51 ;; the terminal in the usual way. Thus, server operation is possible
52 ;; only when Emacs can talk to the terminal at the time you invoke
53 ;; the client. This is possible in four cases:
55 ;; 1. On a window system, where Emacs runs in one window and the
56 ;; program that wants to use "the editor" runs in another.
58 ;; 2. On a multi-terminal system, where Emacs runs on one terminal and the
59 ;; program that wants to use "the editor" runs on another.
61 ;; 3. When the program that wants to use "the editor" is running
62 ;; as a subprocess of Emacs.
64 ;; 4. On a system with job control, when Emacs is suspended, the program
65 ;; that wants to use "the editor" will stop and display
66 ;; "Waiting for Emacs...". It can then be suspended, and Emacs can be
67 ;; brought into the foreground for editing. When done editing, Emacs is
68 ;; suspended again, and the client program is brought into the foreground.
70 ;; The buffer local variable "server-buffer-clients" lists
71 ;; the clients who are waiting for this buffer to be edited.
72 ;; The global variable "server-clients" lists all the waiting clients,
73 ;; and which files are yet to be edited for each.
77 (defvar server-program
(expand-file-name "emacsserver" exec-directory
)
78 "*The program to use as the edit server.")
80 (defvar server-visit-hook nil
81 "*List of hooks to call when visiting a file for the Emacs server.")
83 (defvar server-switch-hook nil
84 "*List of hooks to call when switching to a buffer for the Emacs server.")
86 (defvar server-done-hook nil
87 "*List of hooks to call when done editing a buffer for the Emacs server.")
89 (defvar server-process nil
90 "the current server process")
92 (defvar server-previous-string
"")
94 (defvar server-clients nil
95 "List of current server clients.
96 Each element is (CLIENTID BUFFERS...) where CLIENTID is a string
97 that can be given to the server process to identify a client.
98 When a buffer is marked as \"done\", it is removed from this list.")
100 (defvar server-buffer-clients nil
101 "List of clientids for clients requesting editing of current buffer.")
102 (make-variable-buffer-local 'server-buffer-clients
)
103 ;; Changing major modes should not erase this local.
104 (put 'server-buffer-clients
'permanent-local t
)
106 (defvar server-window nil
107 "*The window to use for selecting Emacs server buffers.
108 If nil, use the selected window.
109 If it is a frame, use the frame's selected window.")
111 (defvar server-temp-file-regexp
"^/tmp/Re\\|/draft$"
112 "*Regexp which should match filenames of temporary files
113 which are deleted and reused after each edit
114 by the programs that invoke the emacs server.")
116 (or (assq 'server-buffer-clients minor-mode-alist
)
117 (setq minor-mode-alist
(cons '(server-buffer-clients " Server") minor-mode-alist
)))
119 ;; If a *server* buffer exists,
120 ;; write STRING to it for logging purposes.
121 (defun server-log (string)
122 (if (get-buffer "*server*")
124 (set-buffer "*server*")
125 (goto-char (point-max))
126 (insert (current-time-string) " " string
)
127 (or (bolp) (newline)))))
129 (defun server-sentinel (proc msg
)
130 (cond ((eq (process-status proc
) 'exit
)
131 (server-log (message "Server subprocess exited")))
132 ((eq (process-status proc
) 'signal
)
133 (server-log (message "Server subprocess killed")))))
136 (defun server-start (&optional leave-dead
)
137 "Allow this Emacs process to be a server for client processes.
138 This starts a server communications subprocess through which
139 client \"editors\" can send your editing commands to this Emacs job.
140 To use the server, set up the program `emacsclient' in the
141 Emacs distribution as your standard \"editor\".
143 Prefix arg means just kill any existing server communications subprocess."
148 (set-process-sentinel server-process nil
)
149 (condition-case () (delete-process server-process
) (error nil
))))
150 (condition-case () (delete-file "~/.emacs_server") (error nil
))
151 (let* ((sysname (system-name))
152 (dot-index (string-match "\\." sysname
)))
154 (delete-file (format "/tmp/esrv%d-%s" (user-uid) sysname
))
156 ;; In case the server file name was made with a domainless hostname,
157 ;; try deleting that name too.
160 (delete-file (format "/tmp/esrv%d-%s" (user-uid)
161 (substring sysname
0 dot-index
)))
163 ;; If we already had a server, clear out associated status.
164 (while server-clients
165 (let ((buffer (nth 1 (car server-clients
))))
166 (server-buffer-done buffer
)))
170 (server-log (message "Restarting server")))
171 ;; Using a pty is wasteful, and the separate session causes
172 ;; annoyance sometimes (some systems kill idle sessions).
173 (let ((process-connection-type nil
))
174 (setq server-process
(start-process "server" nil server-program
)))
175 (set-process-sentinel server-process
'server-sentinel
)
176 (set-process-filter server-process
'server-process-filter
)
177 (process-kill-without-query server-process
)))
179 ;Process a request from the server to edit some files.
180 ;Format of STRING is "Client: CLIENTID PATH PATH PATH... \n"
181 (defun server-process-filter (proc string
)
183 (setq string
(concat server-previous-string string
))
184 ;; If the input is multiple lines,
185 ;; process each line individually.
186 (while (string-match "\n" string
)
187 (let ((request (substring string
0 (match-beginning 0)))
191 ;; Remove this line from STRING.
192 (setq string
(substring string
(match-end 0)))
193 (if (string-match "^Error: " request
)
194 (message "Server error: %s" (substring request
(match-end 0)))
195 (if (string-match "^Client: " request
)
197 (setq request
(substring request
(match-end 0)))
198 (setq client
(list (substring request
0 (string-match " " request
))))
199 (setq request
(substring request
(match-end 0)))
200 (setq foofoo request
)
201 (while (string-match "[^ ]+ " request
)
203 (substring request
(match-beginning 0) (1- (match-end 0)))))
204 (setq request
(substring request
(match-end 0)))
205 (if (string-match "\\`-nowait" arg
)
207 (if (string-match "\\`\\+[0-9]+\\'" arg
)
208 ;; ARG is a line number option.
209 (setq lineno
(read (substring arg
1)))
210 ;; ARG is a file name.
211 ;; Collapse multiple slashes to single slashes.
212 (setq arg
(command-line-normalize-file-name arg
))
214 (cons (list arg lineno
)
217 (server-visit-files files client nowait
)
218 ;; CLIENT is now a list (CLIENTNUM BUFFERS...)
220 (setq server-clients
(cons client server-clients
)))
221 (server-switch-buffer (nth 1 client
))
222 (run-hooks 'server-switch-hook
)
223 (message (substitute-command-keys
224 "When done with a buffer, type \\[server-edit]")))))))
225 ;; Save for later any partial line that remains.
226 (setq server-previous-string string
))
228 (defun server-visit-files (files client
&optional nowait
)
229 "Finds FILES and returns the list CLIENT with the buffers nconc'd.
230 FILES is an alist whose elements are (FILENAME LINENUMBER).
231 NOWAIT non-nil means this client is not waiting for the results,
232 so don't mark these buffers specially, just visit them normally."
233 ;; Bind last-nonmenu-event to force use of keyboard, not mouse, for queries.
234 (let (client-record (last-nonmenu-event t
) (obuf (current-buffer)))
235 ;; Restore the current buffer afterward, but not using save-excursion,
236 ;; because we don't want to save point in this buffer
237 ;; if it happens to be one of those specified by the server.
240 ;; If there is an existing buffer modified or the file is modified,
242 ;; If there is an existing buffer with deleted file, offer to write it.
243 (let* ((filen (car (car files
)))
244 (obuf (get-file-buffer filen
)))
245 (if (and obuf
(set-buffer obuf
))
246 (if (file-exists-p filen
)
247 (if (or (not (verify-visited-file-modtime obuf
))
248 (buffer-modified-p obuf
))
249 (revert-buffer t nil
))
251 (concat "File no longer exists: "
253 ", write buffer to file? "))
255 (set-buffer (find-file-noselect filen
))
256 (run-hooks 'server-visit-hook
)))
257 (goto-line (nth 1 (car files
)))
259 (setq server-buffer-clients
260 (cons (car client
) server-buffer-clients
)))
261 (setq client-record
(cons (current-buffer) client-record
))
262 (setq files
(cdr files
)))
264 (nconc client client-record
)))
266 (defun server-buffer-done (buffer)
267 "Mark BUFFER as \"done\" for its client(s).
268 This buries the buffer, then returns a list of the form (NEXT-BUFFER KILLED).
269 NEXT-BUFFER is another server buffer, as a suggestion for what to select next,
270 or nil. KILLED is t if we killed BUFFER (because it was a temp file)."
271 (let ((running (eq (process-status server-process
) 'run
))
275 (old-clients server-clients
))
277 (let ((client (car old-clients
)))
279 (setq next-buffer
(nth 1 (memq buffer client
))))
281 ;; Delete all dead buffers from CLIENT.
284 (and (bufferp (car tail
))
285 (null (buffer-name (car tail
)))
286 (delq (car tail
) client
))
287 (setq tail
(cdr tail
))))
288 ;; If client now has no pending buffers,
289 ;; tell it that it is done, and forget it entirely.
293 ;; Don't send emacsserver two commands in close succession.
294 ;; It cannot handle that.
295 (or first
(sit-for 1))
297 (send-string server-process
298 (format "Close: %s Done\n" (car client
)))
299 (server-log (format "Close: %s Done\n" (car client
)))))
300 (setq server-clients
(delq client server-clients
))))
301 (setq old-clients
(cdr old-clients
)))
302 (if (and (bufferp buffer
) (buffer-name buffer
))
306 (setq server-buffer-clients nil
)
307 (run-hooks 'server-done-hook
))
308 (if (server-temp-file-p buffer
)
309 (progn (kill-buffer buffer
)
311 (bury-buffer buffer
))))
312 (list next-buffer killed
)))
314 (defun server-temp-file-p (buffer)
315 "Return non-nil if BUFFER contains a file considered temporary.
316 These are files whose names suggest they are repeatedly
317 reused to pass information to another program.
319 The variable `server-temp-file-regexp' controls which filenames
320 are considered temporary."
321 (and (buffer-file-name buffer
)
322 (string-match server-temp-file-regexp
(buffer-file-name buffer
))))
324 (defun server-done ()
325 "Offer to save current buffer, mark it as \"done\" for clients.
326 This buries the buffer, then returns a list of the form (NEXT-BUFFER KILLED).
327 NEXT-BUFFER is another server buffer, as a suggestion for what to select next,
328 or nil. KILLED is t if we killed the BUFFER (because it was a temp file)."
329 (let ((buffer (current-buffer)))
330 (if server-buffer-clients
332 (if (server-temp-file-p buffer
)
333 ;; For a temp file, save, and do make a non-numeric backup
334 ;; (unless make-backup-files is nil).
335 (let ((version-control nil
)
336 (buffer-backed-up nil
))
338 (if (and (buffer-modified-p)
339 (y-or-n-p (concat "Save file " buffer-file-name
"? ")))
340 (save-buffer buffer
)))
341 (server-buffer-done buffer
)))))
343 ;; Ask before killing a server buffer.
344 ;; It was suggested to release its client instead,
345 ;; but I think that is dangerous--the client would proceed
346 ;; using whatever is on disk in that file. -- rms.
347 (defun server-kill-buffer-query-function ()
348 (or (not server-buffer-clients
)
349 (yes-or-no-p (format "Buffer `%s' still has clients; kill it? "
350 (buffer-name (current-buffer))))))
352 (add-hook 'kill-buffer-query-functions
353 'server-kill-buffer-query-function
)
355 (defun server-kill-emacs-query-function ()
357 (tail server-clients
))
358 ;; See if any clients have any buffers that are still alive.
360 (if (memq t
(mapcar 'stringp
(mapcar 'buffer-name
(cdr (car tail
)))))
361 (setq live-client t
))
362 (setq tail
(cdr tail
)))
363 (or (not live-client
)
364 (yes-or-no-p "Server buffers still have clients; exit anyway? "))))
366 (add-hook 'kill-emacs-query-functions
'server-kill-emacs-query-function
)
368 (defun server-edit (&optional arg
)
369 "Switch to next server editing buffer; say \"Done\" for current buffer.
370 If a server buffer is current, it is marked \"done\" and optionally saved.
371 When all of a client's buffers are marked as \"done\", the client is notified.
373 Temporary files such as MH <draft> files are always saved and backed up,
374 no questions asked. (The variable `make-backup-files', if nil, still
375 inhibits a backup; you can set it locally in a particular buffer to
376 prevent a backup for it.) The variable `server-temp-file-regexp' controls
377 which filenames are considered temporary.
379 If invoked with a prefix argument, or if there is no server process running,
380 starts server process and that is all. Invoked by \\[server-edit]."
384 (memq (process-status server-process
) '(signal exit
)))
386 (apply 'server-switch-buffer
(server-done))))
388 (defun server-switch-buffer (&optional next-buffer killed-one
)
389 "Switch to another buffer, preferably one that has a client.
390 Arg NEXT-BUFFER is a suggestion; if it is a live buffer, use it."
391 ;; KILLED-ONE is t in a recursive call
392 ;; if we have already killed one temp-file server buffer.
393 ;; This means we should avoid the final "switch to some other buffer"
394 ;; since we've already effectively done that.
395 (cond ((and (windowp server-window
)
396 (window-live-p server-window
))
397 (select-window server-window
))
398 ((framep server-window
)
399 (if (not (frame-live-p server-window
))
400 (setq server-window
(make-frame)))
401 (select-window (frame-selected-window server-window
))))
402 (if (window-minibuffer-p (selected-window))
403 (select-window (next-window nil
'nomini
0)))
404 ;; Move to a non-dedicated window, if we have one.
405 (let ((last-window (previous-window nil
'nomini
0)))
406 (while (and (window-dedicated-p (selected-window))
407 (not (eq last-window
(selected-window))))
408 (select-window (next-window nil
'nomini
0))))
409 (set-window-dedicated-p (selected-window) nil
)
411 (if (and (bufferp next-buffer
)
412 (buffer-name next-buffer
))
413 (switch-to-buffer next-buffer
)
414 ;; If NEXT-BUFFER is a dead buffer,
415 ;; remove the server records for it
416 ;; and try the next surviving server buffer.
417 (apply 'server-switch-buffer
418 (server-buffer-done next-buffer
)))
420 (server-switch-buffer (nth 1 (car server-clients
)) killed-one
)
422 (switch-to-buffer (other-buffer))))))
424 (global-set-key "\C-x#" 'server-edit
)
428 ;;; server.el ends here