(defgroup server nil
"Emacs running as a server process."
:group 'external)
(defcustom server-program (expand-file-name "emacsserver" exec-directory)
"*The program to use as the edit server."
:group 'server
:type 'string)
(defcustom server-visit-hook nil
"*List of hooks to call when visiting a file for the Emacs server."
:group 'server
:type '(repeat function))
(defcustom server-switch-hook nil
"*List of hooks to call when switching to a buffer for the Emacs server."
:group 'server
:type '(repeat function))
(defcustom server-done-hook nil
"*List of hooks to call when done editing a buffer for the Emacs server."
:group 'server
:type '(repeat function))
(defvar server-process nil
"the current server process")
(defvar server-previous-string "")
(defvar server-clients nil
"List of current server clients.
Each element is (CLIENTID BUFFERS...) where CLIENTID is a string
that can be given to the server process to identify a client.
When a buffer is marked as \"done\", it is removed from this list.")
(defvar server-buffer-clients nil
"List of clientids for clients requesting editing of current buffer.")
(make-variable-buffer-local 'server-buffer-clients)
(put 'server-buffer-clients 'permanent-local t)
(defvar server-window nil
"*The window to use for selecting Emacs server buffers.
If nil, use the selected window.
If it is a frame, use the frame's selected window.")
(defcustom server-temp-file-regexp "^/tmp/Re\\|/draft$"
"*Regexp which should match filenames of temporary files
which are deleted and reused after each edit
by the programs that invoke the emacs server."
:group 'server
:type 'regexp)
(or (assq 'server-buffer-clients minor-mode-alist)
(setq minor-mode-alist (cons '(server-buffer-clients " Server") minor-mode-alist)))
(defun server-log (string)
(if (get-buffer "*server*")
(save-excursion
(set-buffer "*server*")
(goto-char (point-max))
(insert (current-time-string) " " string)
(or (bolp) (newline)))))
(defun server-sentinel (proc msg)
(cond ((eq (process-status proc) 'exit)
(server-log (message "Server subprocess exited")))
((eq (process-status proc) 'signal)
(server-log (message "Server subprocess killed")))))
(defun server-start (&optional leave-dead)
"Allow this Emacs process to be a server for client processes.
This starts a server communications subprocess through which
client \"editors\" can send your editing commands to this Emacs job.
To use the server, set up the program `emacsclient' in the
Emacs distribution as your standard \"editor\".
Prefix arg means just kill any existing server communications subprocess."
(interactive "P")
(if server-process
(progn
(set-process-sentinel server-process nil)
(condition-case () (delete-process server-process) (error nil))))
(let* ((sysname (system-name))
(dot-index (string-match "\\." sysname)))
(condition-case ()
(delete-file (format "~/.emacs-server-%s" sysname))
(error nil))
(condition-case ()
(delete-file (format "/tmp/esrv%d-%s" (user-uid) sysname))
(error nil))
(if dot-index
(let ((shortname (substring sysname 0 dot-index)))
(condition-case ()
(delete-file (format "~/.emacs-server-%s" shortname))
(error nil))
(condition-case ()
(delete-file (format "/tmp/esrv%d-%s" (user-uid) shortname))
(error nil)))))
(while server-clients
(let ((buffer (nth 1 (car server-clients))))
(server-buffer-done buffer)))
(if leave-dead
nil
(if server-process
(server-log (message "Restarting server")))
(let ((process-connection-type nil))
(setq server-process (start-process "server" nil server-program)))
(set-process-sentinel server-process 'server-sentinel)
(set-process-filter server-process 'server-process-filter)
(set-process-coding-system server-process 'raw-text 'raw-text)
(process-kill-without-query server-process)))
(defun server-process-filter (proc string)
(server-log string)
(setq string (concat server-previous-string string))
(while (string-match "\n" string)
(let ((request (substring string 0 (match-beginning 0)))
(coding-system (and default-enable-multibyte-characters
(or file-name-coding-system
default-file-name-coding-system)))
client nowait
(files nil)
(lineno 1))
(setq string (substring string (match-end 0)))
(if (string-match "^Error: " request)
(message "Server error: %s" (substring request (match-end 0)))
(if (string-match "^Client: " request)
(progn
(setq request (substring request (match-end 0)))
(setq client (list (substring request 0 (string-match " " request))))
(setq request (substring request (match-end 0)))
(while (string-match "[^ ]+ " request)
(let ((arg
(substring request (match-beginning 0) (1- (match-end 0))))
(pos 0))
(setq request (substring request (match-end 0)))
(if (string-match "\\`-nowait" arg)
(setq nowait t)
(if (string-match "\\`\\+[0-9]+\\'" arg)
(setq lineno (read (substring arg 1)))
(setq arg (command-line-normalize-file-name arg))
(while (string-match "&." arg pos)
(setq pos (1+ (match-beginning 0)))
(let ((nextchar (aref arg pos)))
(cond ((= nextchar ?&)
(setq arg (replace-match "&" t t arg)))
((= nextchar ?-)
(setq arg (replace-match "-" t t arg)))
(t
(setq arg (replace-match " " t t arg))))))
(if coding-system
(setq arg (decode-coding-string arg coding-system)))
(setq files
(cons (list arg lineno)
files))
(setq lineno 1)))))
(server-visit-files files client nowait)
(or nowait
(setq server-clients (cons client server-clients)))
(server-switch-buffer (nth 1 client))
(run-hooks 'server-switch-hook)
(message (substitute-command-keys
"When done with a buffer, type \\[server-edit]")))))))
(setq server-previous-string string))
(defun server-visit-files (files client &optional nowait)
"Finds FILES and returns the list CLIENT with the buffers nconc'd.
FILES is an alist whose elements are (FILENAME LINENUMBER).
NOWAIT non-nil means this client is not waiting for the results,
so don't mark these buffers specially, just visit them normally."
(let (client-record (last-nonmenu-event t) (obuf (current-buffer)))
(unwind-protect
(while files
(let* ((filen (car (car files)))
(obuf (get-file-buffer filen)))
(if (and obuf (set-buffer obuf))
(if (file-exists-p filen)
(if (or (not (verify-visited-file-modtime obuf))
(buffer-modified-p obuf))
(revert-buffer t nil))
(if (y-or-n-p
(concat "File no longer exists: "
filen
", write buffer to file? "))
(write-file filen)))
(set-buffer (find-file-noselect filen))
(run-hooks 'server-visit-hook)))
(goto-line (nth 1 (car files)))
(if (not nowait)
(setq server-buffer-clients
(cons (car client) server-buffer-clients)))
(setq client-record (cons (current-buffer) client-record))
(setq files (cdr files)))
(set-buffer obuf))
(nconc client client-record)))
(defun server-buffer-done (buffer &optional for-killing)
"Mark BUFFER as \"done\" for its client(s).
This buries the buffer, then returns a list of the form (NEXT-BUFFER KILLED).
NEXT-BUFFER is another server buffer, as a suggestion for what to select next,
or nil. KILLED is t if we killed BUFFER
\(typically, because it was visiting a temp file)."
(let ((running (eq (process-status server-process) 'run))
(next-buffer nil)
(killed nil)
(first t)
(old-clients server-clients))
(while old-clients
(let ((client (car old-clients)))
(or next-buffer
(setq next-buffer (nth 1 (memq buffer client))))
(delq buffer client)
(let ((tail client))
(while tail
(and (bufferp (car tail))
(null (buffer-name (car tail)))
(delq (car tail) client))
(setq tail (cdr tail))))
(if (cdr client) nil
(if running
(progn
(or first (sit-for 1))
(setq first nil)
(send-string server-process
(format "Close: %s Done\n" (car client)))
(server-log (format "Close: %s Done\n" (car client)))))
(setq server-clients (delq client server-clients))))
(setq old-clients (cdr old-clients)))
(if (and (bufferp buffer) (buffer-name buffer))
(let ((server-kill-buffer-running t))
(save-excursion
(set-buffer buffer)
(setq server-buffer-clients nil)
(run-hooks 'server-done-hook))
(if (null (buffer-name buffer))
(setq killed t)
(unless for-killing
(if (server-temp-file-p buffer)
(progn (kill-buffer buffer)
(setq killed t))
(bury-buffer buffer))))))
(list next-buffer killed)))
(defun server-temp-file-p (buffer)
"Return non-nil if BUFFER contains a file considered temporary.
These are files whose names suggest they are repeatedly
reused to pass information to another program.
The variable `server-temp-file-regexp' controls which filenames
are considered temporary."
(and (buffer-file-name buffer)
(string-match server-temp-file-regexp (buffer-file-name buffer))))
(defun server-done ()
"Offer to save current buffer, mark it as \"done\" for clients.
This buries the buffer, then returns a list of the form (NEXT-BUFFER KILLED).
NEXT-BUFFER is another server buffer, as a suggestion for what to select next,
or nil. KILLED is t if we killed BUFFER
\(typically, because it was visiting a temp file)."
(let ((buffer (current-buffer)))
(if server-buffer-clients
(progn
(if (server-temp-file-p buffer)
(let ((version-control nil)
(buffer-backed-up nil))
(save-buffer))
(if (and (buffer-modified-p)
buffer-file-name
(y-or-n-p (concat "Save file " buffer-file-name "? ")))
(save-buffer buffer)))
(server-buffer-done buffer)))))
(defun server-kill-buffer-query-function ()
(or (not server-buffer-clients)
(yes-or-no-p (format "Buffer `%s' still has clients; kill it? "
(buffer-name (current-buffer))))))
(add-hook 'kill-buffer-query-functions
'server-kill-buffer-query-function)
(defun server-kill-emacs-query-function ()
(let (live-client
(tail server-clients))
(while tail
(if (memq t (mapcar 'stringp (mapcar 'buffer-name (cdr (car tail)))))
(setq live-client t))
(setq tail (cdr tail)))
(or (not live-client)
(yes-or-no-p "Server buffers still have clients; exit anyway? "))))
(add-hook 'kill-emacs-query-functions 'server-kill-emacs-query-function)
(defvar server-kill-buffer-running nil
"Non-nil while `server-kill-buffer' or `server-buffer-done' is running.")
(add-hook 'kill-buffer-hook 'server-kill-buffer)
(defun server-kill-buffer ()
(or server-kill-buffer-running
(and server-buffer-clients
(let ((server-kill-buffer-running t))
(when server-process
(server-buffer-done (current-buffer) t))))))
(defun server-edit (&optional arg)
"Switch to next server editing buffer; say \"Done\" for current buffer.
If a server buffer is current, it is marked \"done\" and optionally saved.
When all of a client's buffers are marked as \"done\", the client is notified.
Temporary files such as MH <draft> files are always saved and backed up,
no questions asked. (The variable `make-backup-files', if nil, still
inhibits a backup; you can set it locally in a particular buffer to
prevent a backup for it.) The variable `server-temp-file-regexp' controls
which filenames are considered temporary.
If invoked with a prefix argument, or if there is no server process running,
starts server process and that is all. Invoked by \\[server-edit]."
(interactive "P")
(if (or arg
(not server-process)
(memq (process-status server-process) '(signal exit)))
(server-start nil)
(apply 'server-switch-buffer (server-done))))
(defun server-switch-buffer (&optional next-buffer killed-one)
"Switch to another buffer, preferably one that has a client.
Arg NEXT-BUFFER is a suggestion; if it is a live buffer, use it."
(cond ((and (windowp server-window)
(window-live-p server-window))
(select-window server-window))
((framep server-window)
(if (not (frame-live-p server-window))
(setq server-window (make-frame)))
(select-window (frame-selected-window server-window))))
(if (window-minibuffer-p (selected-window))
(select-window (next-window nil 'nomini 0)))
(let ((last-window (previous-window nil 'nomini 0)))
(while (and (window-dedicated-p (selected-window))
(not (eq last-window (selected-window))))
(select-window (next-window nil 'nomini 0))))
(set-window-dedicated-p (selected-window) nil)
(if next-buffer
(if (and (bufferp next-buffer)
(buffer-name next-buffer))
(switch-to-buffer next-buffer)
(apply 'server-switch-buffer
(server-buffer-done next-buffer)))
(if server-clients
(server-switch-buffer (nth 1 (car server-clients)) killed-one)
(if (not killed-one)
(switch-to-buffer (other-buffer))))))
(global-set-key "\C-x#" 'server-edit)
(provide 'server)