1 ;;; server.el --- Lisp code for GNU Emacs running as server process.
3 ;; Copyright (C) 1986, 1987, 1992 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
24 ;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
28 ;;; This Lisp code is run in Emacs when it is to operate as
29 ;;; a server for other processes.
31 ;;; Load this library and do M-x server-edit to enable Emacs as a server.
32 ;;; Emacs runs the program ../arch-lib/emacsserver as a subprocess
33 ;;; for communication with clients. If there are no client buffers to edit,
34 ;;; server-edit acts like (switch-to-buffer (other-buffer))
36 ;;; When some other program runs "the editor" to edit a file,
37 ;;; "the editor" can be the Emacs client program ../lib-src/emacsclient.
38 ;;; This program transmits the file names to Emacs through
39 ;;; the server subprocess, and Emacs visits them and lets you edit them.
41 ;;; Note that any number of clients may dispatch files to emacs to be edited.
43 ;;; When you finish editing a Server buffer, again call server-edit
44 ;;; to mark that buffer as done for the client and switch to the next
45 ;;; Server buffer. When all the buffers for a client have been edited
46 ;;; and exited with server-edit, the client "editor" will return
47 ;;; to the program that invoked it.
49 ;;; Your editing commands and Emacs's display output go to and from
50 ;;; the terminal in the usual way. Thus, server operation is possible
51 ;;; only when Emacs can talk to the terminal at the time you invoke
52 ;;; the client. This is possible in four cases:
54 ;;; 1. On a window system, where Emacs runs in one window and the
55 ;;; program that wants to use "the editor" runs in another.
57 ;;; 2. On a multi-terminal system, where Emacs runs on one terminal and the
58 ;;; program that wants to use "the editor" runs on another.
60 ;;; 3. When the program that wants to use "the editor" is running
61 ;;; as a subprocess of Emacs.
63 ;;; 4. On a system with job control, when Emacs is suspended, the program
64 ;;; that wants to use "the editor" will stop and display
65 ;;; "Waiting for Emacs...". It can then be suspended, and Emacs can be
66 ;;; brought into the foreground for editing. When done editing, Emacs is
67 ;;; suspended again, and the client program is brought into the foreground.
69 ;;; The buffer local variable "server-buffer-clients" lists
70 ;;; the clients who are waiting for this buffer to be edited.
71 ;;; The global variable "server-clients" lists all the waiting clients,
72 ;;; and which files are yet to be edited for each.
76 (defvar server-program
(expand-file-name "emacsserver" exec-directory
)
77 "*The program to use as the edit server.")
79 (defvar server-visit-hook nil
80 "*List of hooks to call when visiting a file for the Emacs server.")
82 (defvar server-switch-hook nil
83 "*List of hooks to call when switching to a buffer for the Emacs server.")
85 (defvar server-process nil
86 "the current server process")
88 (defvar server-previous-string
"")
90 (defvar server-clients nil
91 "List of current server clients.
92 Each element is (CLIENTID FILES...) where CLIENTID is a string
93 that can be given to the server process to identify a client.
94 When a buffer is marked as \"done\", it is removed from this list.")
96 (defvar server-buffer-clients nil
97 "List of clientids for clients requesting editing of current buffer.")
98 (make-variable-buffer-local 'server-buffer-clients
)
99 ;; Changing major modes should not erase this local.
100 (put 'server-buffer-clients
'permanent-local t
)
102 (defvar server-window nil
103 "*The window to use for selecting Emacs server buffers.
104 If nil, use the selected window.
105 If it is a frame, use the frame's selected window.")
107 (defvar server-temp-file-regexp
"^/tmp/Re\\|/draft$"
108 "*Regexp which should match filenames of temporary files
109 which are deleted and reused after each edit
110 by the programs that invoke the emacs server.")
112 (or (assq 'server-buffer-clients minor-mode-alist
)
113 (setq minor-mode-alist
(cons '(server-buffer-clients " Server") minor-mode-alist
)))
115 ;; If a *server* buffer exists,
116 ;; write STRING to it for logging purposes.
117 (defun server-log (string)
118 (if (get-buffer "*server*")
120 (set-buffer "*server*")
121 (goto-char (point-max))
123 (or (bobp) (newline)))))
125 (defun server-sentinel (proc msg
)
126 (cond ((eq (process-status proc
) 'exit
)
127 (server-log (message "Server subprocess exited")))
128 ((eq (process-status proc
) 'signal
)
129 (server-log (message "Server subprocess killed")))))
132 (defun server-start (&optional leave-dead
)
133 "Allow this Emacs process to be a server for client processes.
134 This starts a server communications subprocess through which
135 client \"editors\" can send your editing commands to this Emacs job.
136 To use the server, set up the program `etc/emacsclient' in the
137 Emacs distribution as your standard \"editor\".
139 Prefix arg means just kill any existing server communications subprocess."
144 (set-process-sentinel server-process nil
)
145 (condition-case () (delete-process server-process
) (error nil
))))
146 (condition-case () (delete-file "~/.emacs_server") (error nil
))
147 ;; If we already had a server, clear out associated status.
148 (while server-clients
149 (let ((buffer (nth 1 (car server-clients
))))
150 (server-buffer-done buffer
)))
154 (server-log (message "Restarting server")))
155 (setq server-process
(start-process "server" nil server-program
))
156 (set-process-sentinel server-process
'server-sentinel
)
157 (set-process-filter server-process
'server-process-filter
)
158 (process-kill-without-query server-process
)))
160 ;Process a request from the server to edit some files.
161 ;Format of STRING is "Client: CLIENTID PATH PATH PATH... \n"
162 (defun server-process-filter (proc string
)
164 (setq string
(concat server-previous-string string
))
165 (if (not (and (eq ?
\n (aref string
(1- (length string
))))
166 (eq 0 (string-match "Client: " string
))))
167 ;; If input is not complete, save it for later.
168 (setq server-previous-string string
)
169 ;; If it is complete, process it now, and discard what was saved.
170 (setq string
(substring string
(match-end 0)))
171 (setq server-previous-string
"")
172 (let ((client (list (substring string
0 (string-match " " string
))))
175 (setq string
(substring string
(match-end 0)))
176 (while (string-match "[^ ]+ " string
)
178 (substring string
(match-beginning 0) (1- (match-end 0)))))
179 (setq string
(substring string
(match-end 0)))
180 (if (string-match "\\`\\+[0-9]+\\'" arg
)
181 (setq lineno
(read (substring arg
1)))
183 (cons (list arg lineno
)
186 (server-visit-files files client
)
187 ;; CLIENT is now a list (CLIENTNUM BUFFERS...)
188 (setq server-clients
(cons client server-clients
))
189 (server-switch-buffer (nth 1 client
))
190 (run-hooks 'server-switch-hook
)
191 (message (substitute-command-keys
192 "When done with a buffer, type \\[server-edit].")))))
194 (defun server-visit-files (files client
)
195 "Finds FILES and returns the list CLIENT with the buffers nconc'd.
196 FILES is an alist whose elements are (FILENAME LINENUMBER)."
197 (let (client-record (obuf (current-buffer)))
198 ;; Restore the current buffer afterward, but not using save-excursion,
199 ;; because we don't want to save point in this buffer
200 ;; if it happens to be one of those specified by the server.
203 ;; If there is an existing buffer modified or the file is modified,
205 ;; If there is an existing buffer with deleted file, offer to write it.
206 (let* ((filen (car (car files
)))
207 (obuf (get-file-buffer filen
)))
208 (if (and obuf
(set-buffer obuf
))
209 (if (file-exists-p filen
)
210 (if (or (not (verify-visited-file-modtime obuf
))
211 (buffer-modified-p obuf
))
212 (revert-buffer t nil
))
214 (concat "File no longer exists: "
216 ", write buffer to file? "))
218 (set-buffer (find-file-noselect filen
))
219 (run-hooks 'server-visit-hook
)))
220 (goto-line (nth 1 (car files
)))
221 (setq server-buffer-clients
(cons (car client
) server-buffer-clients
))
222 (setq client-record
(cons (current-buffer) client-record
))
223 (setq files
(cdr files
)))
225 (nconc client client-record
)))
227 (defun server-buffer-done (buffer)
228 "Mark BUFFER as \"done\" for its client(s).
229 Buries the buffer, and returns another server buffer
230 as a suggestion for what to select next."
231 (let ((running (eq (process-status server-process
) 'run
))
233 (old-clients server-clients
))
235 (let ((client (car old-clients
)))
237 (setq next-buffer
(nth 1 (memq buffer client
))))
239 ;; If client now has no pending buffers,
240 ;; tell it that it is done, and forget it entirely.
244 (send-string server-process
245 (format "Close: %s Done\n" (car client
)))
246 (server-log (format "Close: %s Done\n" (car client
)))))
247 (setq server-clients
(delq client server-clients
))))
248 (setq old-clients
(cdr old-clients
)))
249 (if (buffer-name buffer
)
253 (setq server-buffer-clients nil
))
254 (bury-buffer buffer
)))
257 (defun server-temp-file-p (buffer)
258 "Return non-nil if BUFFER contains a file considered temporary.
259 These are files whose names suggest they are repeatedly
260 reused to pass information to another program.
262 The variable `server-temp-file-regexp' controls which filenames
263 are considered temporary."
264 (and (buffer-file-name buffer
)
265 (string-match server-temp-file-regexp
(buffer-file-name buffer
))))
267 (defun server-done ()
268 "Offer to save current buffer, mark it as \"done\" for clients.
269 Then bury it, and return a suggested buffer to select next."
270 (let ((buffer (current-buffer)))
271 (if server-buffer-clients
272 (let (suggested-buffer)
273 (if (server-temp-file-p buffer
)
274 ;; For a temp file, save, and do make a non-numeric backup
275 ;; (unless make-backup-files is nil).
276 (let ((version-control nil
)
277 (buffer-backed-up nil
))
280 (setq suggested-buffer
(current-buffer)))
281 (if (and (buffer-modified-p)
282 (y-or-n-p (concat "Save file " buffer-file-name
"? ")))
283 (save-buffer buffer
)))
284 (or (server-buffer-done buffer
) suggested-buffer
)))))
286 ;; If a server buffer is killed, release its client.
287 ;; I'm not sure this is really a good idea--do you want the client
288 ;; to proceed using whatever is on disk in that file?
289 (add-hook 'kill-buffer-query-functions
292 (or (not server-buffer-clients
)
293 (yes-or-no-p (format "Buffer `%s' still has clients; kill it? "
294 (buffer-name (current-buffer))))))))
296 (add-hook 'kill-emacs-query-functions
299 (or (not server-clients
)
300 (yes-or-no-p "Server buffers still have clients; exit anyway? ")))))
302 (defun server-edit (&optional arg
)
303 "Switch to next server editing buffer; say \"Done\" for current buffer.
304 If a server buffer is current, it is marked \"done\" and optionally saved.
305 When all of a client's buffers are marked as \"done\", the client is notified.
307 Temporary files such as MH <draft> files are always saved and backed up,
308 no questions asked. (The variable `make-backup-files', if nil, still
309 inhibits a backup; you can set it locally in a particular buffer to
310 prevent a backup for it.) The variable `server-temp-file-regexp' controls
311 which filenames are considered temporary.
313 If invoked with a prefix argument, or if there is no server process running,
314 starts server process and that is all. Invoked by \\[server-edit]."
319 (memq (process-status server-process
) '(signal exit
)))
321 (server-switch-buffer (server-done))))
323 (defun server-switch-buffer (next-buffer)
324 "Switch to another buffer, preferably one that has a client.
325 Arg NEXT-BUFFER is a suggestion; if it is a live buffer, use it."
326 (cond ((windowp server-window
)
327 (select-window server-window
))
328 ((framep server-window
)
329 (select-window (frame-selected-window server-window
))))
330 (if (window-minibuffer-p (selected-window))
331 (select-window (next-window nil
'nomini t
)))
333 (if (and (bufferp next-buffer
)
334 (buffer-name next-buffer
))
335 (switch-to-buffer next-buffer
)
336 ;; If NEXT-BUFFER is a dead buffer,
337 ;; remove the server records for it
338 ;; and try the next surviving server buffer.
339 (server-switch-buffer
340 (server-buffer-done next-buffer
)))
342 (server-switch-buffer (nth 1 (car server-clients
)))
343 (switch-to-buffer (other-buffer)))))
345 (global-set-key "\C-x#" 'server-edit
)
349 ;;; server.el ends here