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 ;; Delete the socket files made by previous server invocations.
151 (let* ((sysname (system-name))
152 (dot-index (string-match "\\." sysname
)))
154 (delete-file (format "~/.emacs-server-%s" sysname
))
157 (delete-file (format "/tmp/esrv%d-%s" (user-uid) sysname
))
159 ;; In case the server file name was made with a domainless hostname,
160 ;; try deleting that name too.
162 (let ((shortname (substring sysname
0 dot-index
)))
164 (delete-file (format "~/.emacs-server-%s" shortname
))
167 (delete-file (format "/tmp/esrv%d-%s" (user-uid) shortname
))
169 ;; If this Emacs already had a server, clear out associated status.
170 (while server-clients
171 (let ((buffer (nth 1 (car server-clients
))))
172 (server-buffer-done buffer
)))
176 (server-log (message "Restarting server")))
177 ;; Using a pty is wasteful, and the separate session causes
178 ;; annoyance sometimes (some systems kill idle sessions).
179 (let ((process-connection-type nil
))
180 (setq server-process
(start-process "server" nil server-program
)))
181 (set-process-sentinel server-process
'server-sentinel
)
182 (set-process-filter server-process
'server-process-filter
)
183 (process-kill-without-query server-process
)))
185 ;Process a request from the server to edit some files.
186 ;Format of STRING is "Client: CLIENTID PATH PATH PATH... \n"
187 (defun server-process-filter (proc string
)
189 (setq string
(concat server-previous-string string
))
190 ;; If the input is multiple lines,
191 ;; process each line individually.
192 (while (string-match "\n" string
)
193 (let ((request (substring string
0 (match-beginning 0)))
197 ;; Remove this line from STRING.
198 (setq string
(substring string
(match-end 0)))
199 (if (string-match "^Error: " request
)
200 (message "Server error: %s" (substring request
(match-end 0)))
201 (if (string-match "^Client: " request
)
203 (setq request
(substring request
(match-end 0)))
204 (setq client
(list (substring request
0 (string-match " " request
))))
205 (setq request
(substring request
(match-end 0)))
206 (while (string-match "[^ ]+ " request
)
208 (substring request
(match-beginning 0) (1- (match-end 0))))
210 (setq request
(substring request
(match-end 0)))
211 (if (string-match "\\`-nowait" arg
)
213 (if (string-match "\\`\\+[0-9]+\\'" arg
)
214 ;; ARG is a line number option.
215 (setq lineno
(read (substring arg
1)))
216 ;; ARG is a file name.
217 ;; Collapse multiple slashes to single slashes.
218 (setq arg
(command-line-normalize-file-name arg
))
219 ;; Undo the quoting that emacsclient does
220 ;; for certain special characters.
221 (while (string-match "&." arg pos
)
222 (setq pos
(1+ (match-beginning 0)))
223 (let ((nextchar (aref arg pos
)))
224 (cond ((= nextchar ?
&)
225 (setq arg
(replace-match "&" t t arg
)))
227 (setq arg
(replace-match "-" t t arg
)))
229 (setq arg
(replace-match " " t t arg
))))))
231 (cons (list arg lineno
)
234 (server-visit-files files client nowait
)
235 ;; CLIENT is now a list (CLIENTNUM BUFFERS...)
237 (setq server-clients
(cons client server-clients
)))
238 (server-switch-buffer (nth 1 client
))
239 (run-hooks 'server-switch-hook
)
240 (message (substitute-command-keys
241 "When done with a buffer, type \\[server-edit]")))))))
242 ;; Save for later any partial line that remains.
243 (setq server-previous-string string
))
245 (defun server-visit-files (files client
&optional nowait
)
246 "Finds FILES and returns the list CLIENT with the buffers nconc'd.
247 FILES is an alist whose elements are (FILENAME LINENUMBER).
248 NOWAIT non-nil means this client is not waiting for the results,
249 so don't mark these buffers specially, just visit them normally."
250 ;; Bind last-nonmenu-event to force use of keyboard, not mouse, for queries.
251 (let (client-record (last-nonmenu-event t
) (obuf (current-buffer)))
252 ;; Restore the current buffer afterward, but not using save-excursion,
253 ;; because we don't want to save point in this buffer
254 ;; if it happens to be one of those specified by the server.
257 ;; If there is an existing buffer modified or the file is modified,
259 ;; If there is an existing buffer with deleted file, offer to write it.
260 (let* ((filen (car (car files
)))
261 (obuf (get-file-buffer filen
)))
262 (if (and obuf
(set-buffer obuf
))
263 (if (file-exists-p filen
)
264 (if (or (not (verify-visited-file-modtime obuf
))
265 (buffer-modified-p obuf
))
266 (revert-buffer t nil
))
268 (concat "File no longer exists: "
270 ", write buffer to file? "))
272 (set-buffer (find-file-noselect filen
))
273 (run-hooks 'server-visit-hook
)))
274 (goto-line (nth 1 (car files
)))
276 (setq server-buffer-clients
277 (cons (car client
) server-buffer-clients
)))
278 (setq client-record
(cons (current-buffer) client-record
))
279 (setq files
(cdr files
)))
281 (nconc client client-record
)))
283 (defun server-buffer-done (buffer)
284 "Mark BUFFER as \"done\" for its client(s).
285 This buries the buffer, then returns a list of the form (NEXT-BUFFER KILLED).
286 NEXT-BUFFER is another server buffer, as a suggestion for what to select next,
287 or nil. KILLED is t if we killed BUFFER (because it was a temp file)."
288 (let ((running (eq (process-status server-process
) 'run
))
292 (old-clients server-clients
))
294 (let ((client (car old-clients
)))
296 (setq next-buffer
(nth 1 (memq buffer client
))))
298 ;; Delete all dead buffers from CLIENT.
301 (and (bufferp (car tail
))
302 (null (buffer-name (car tail
)))
303 (delq (car tail
) client
))
304 (setq tail
(cdr tail
))))
305 ;; If client now has no pending buffers,
306 ;; tell it that it is done, and forget it entirely.
310 ;; Don't send emacsserver two commands in close succession.
311 ;; It cannot handle that.
312 (or first
(sit-for 1))
314 (send-string server-process
315 (format "Close: %s Done\n" (car client
)))
316 (server-log (format "Close: %s Done\n" (car client
)))))
317 (setq server-clients
(delq client server-clients
))))
318 (setq old-clients
(cdr old-clients
)))
319 (if (and (bufferp buffer
) (buffer-name buffer
))
323 (setq server-buffer-clients nil
)
324 (run-hooks 'server-done-hook
))
325 (if (server-temp-file-p buffer
)
326 (progn (kill-buffer buffer
)
328 (bury-buffer buffer
))))
329 (list next-buffer killed
)))
331 (defun server-temp-file-p (buffer)
332 "Return non-nil if BUFFER contains a file considered temporary.
333 These are files whose names suggest they are repeatedly
334 reused to pass information to another program.
336 The variable `server-temp-file-regexp' controls which filenames
337 are considered temporary."
338 (and (buffer-file-name buffer
)
339 (string-match server-temp-file-regexp
(buffer-file-name buffer
))))
341 (defun server-done ()
342 "Offer to save current buffer, mark it as \"done\" for clients.
343 This buries the buffer, then returns a list of the form (NEXT-BUFFER KILLED).
344 NEXT-BUFFER is another server buffer, as a suggestion for what to select next,
345 or nil. KILLED is t if we killed the BUFFER (because it was a temp file)."
346 (let ((buffer (current-buffer)))
347 (if server-buffer-clients
349 (if (server-temp-file-p buffer
)
350 ;; For a temp file, save, and do make a non-numeric backup
351 ;; (unless make-backup-files is nil).
352 (let ((version-control nil
)
353 (buffer-backed-up nil
))
355 (if (and (buffer-modified-p)
356 (y-or-n-p (concat "Save file " buffer-file-name
"? ")))
357 (save-buffer buffer
)))
358 (server-buffer-done buffer
)))))
360 ;; Ask before killing a server buffer.
361 ;; It was suggested to release its client instead,
362 ;; but I think that is dangerous--the client would proceed
363 ;; using whatever is on disk in that file. -- rms.
364 (defun server-kill-buffer-query-function ()
365 (or (not server-buffer-clients
)
366 (yes-or-no-p (format "Buffer `%s' still has clients; kill it? "
367 (buffer-name (current-buffer))))))
369 (add-hook 'kill-buffer-query-functions
370 'server-kill-buffer-query-function
)
372 (defun server-kill-emacs-query-function ()
374 (tail server-clients
))
375 ;; See if any clients have any buffers that are still alive.
377 (if (memq t
(mapcar 'stringp
(mapcar 'buffer-name
(cdr (car tail
)))))
378 (setq live-client t
))
379 (setq tail
(cdr tail
)))
380 (or (not live-client
)
381 (yes-or-no-p "Server buffers still have clients; exit anyway? "))))
383 (add-hook 'kill-emacs-query-functions
'server-kill-emacs-query-function
)
385 (defun server-edit (&optional arg
)
386 "Switch to next server editing buffer; say \"Done\" for current buffer.
387 If a server buffer is current, it is marked \"done\" and optionally saved.
388 When all of a client's buffers are marked as \"done\", the client is notified.
390 Temporary files such as MH <draft> files are always saved and backed up,
391 no questions asked. (The variable `make-backup-files', if nil, still
392 inhibits a backup; you can set it locally in a particular buffer to
393 prevent a backup for it.) The variable `server-temp-file-regexp' controls
394 which filenames are considered temporary.
396 If invoked with a prefix argument, or if there is no server process running,
397 starts server process and that is all. Invoked by \\[server-edit]."
401 (memq (process-status server-process
) '(signal exit
)))
403 (apply 'server-switch-buffer
(server-done))))
405 (defun server-switch-buffer (&optional next-buffer killed-one
)
406 "Switch to another buffer, preferably one that has a client.
407 Arg NEXT-BUFFER is a suggestion; if it is a live buffer, use it."
408 ;; KILLED-ONE is t in a recursive call
409 ;; if we have already killed one temp-file server buffer.
410 ;; This means we should avoid the final "switch to some other buffer"
411 ;; since we've already effectively done that.
412 (cond ((and (windowp server-window
)
413 (window-live-p server-window
))
414 (select-window server-window
))
415 ((framep server-window
)
416 (if (not (frame-live-p server-window
))
417 (setq server-window
(make-frame)))
418 (select-window (frame-selected-window server-window
))))
419 (if (window-minibuffer-p (selected-window))
420 (select-window (next-window nil
'nomini
0)))
421 ;; Move to a non-dedicated window, if we have one.
422 (let ((last-window (previous-window nil
'nomini
0)))
423 (while (and (window-dedicated-p (selected-window))
424 (not (eq last-window
(selected-window))))
425 (select-window (next-window nil
'nomini
0))))
426 (set-window-dedicated-p (selected-window) nil
)
428 (if (and (bufferp next-buffer
)
429 (buffer-name next-buffer
))
430 (switch-to-buffer next-buffer
)
431 ;; If NEXT-BUFFER is a dead buffer,
432 ;; remove the server records for it
433 ;; and try the next surviving server buffer.
434 (apply 'server-switch-buffer
435 (server-buffer-done next-buffer
)))
437 (server-switch-buffer (nth 1 (car server-clients
)) killed-one
)
439 (switch-to-buffer (other-buffer))))))
441 (global-set-key "\C-x#" 'server-edit
)
445 ;;; server.el ends here