xref: /386bsd/usr/local/lib/emacs/19.25/lisp/time.el (revision a2142627)
1;;; time.el --- display time and load in mode line of Emacs.
2
3;; Copyright (C) 1985, 1986, 1987, 1993, 1994 Free Software Foundation, Inc.
4
5;; Maintainer: FSF
6
7;; This file is part of GNU Emacs.
8
9;; GNU Emacs is free software; you can redistribute it and/or modify
10;; it under the terms of the GNU General Public License as published by
11;; the Free Software Foundation; either version 2, or (at your option)
12;; any later version.
13
14;; GNU Emacs is distributed in the hope that it will be useful,
15;; but WITHOUT ANY WARRANTY; without even the implied warranty of
16;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17;; GNU General Public License for more details.
18
19;; You should have received a copy of the GNU General Public License
20;; along with GNU Emacs; see the file COPYING.  If not, write to
21;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
22
23;;; Commentary:
24
25;;; Facilities to display current time/date and a new-mail indicator
26;;; in the Emacs mode line.  The single entry point is `display-time'.
27
28;;; Code:
29
30(defvar display-time-mail-file nil
31  "*File name of mail inbox file, for indicating existence of new mail.
32Default is system-dependent, and is the same as used by Rmail.")
33
34;;;###autoload
35(defvar display-time-day-and-date nil "\
36*Non-nil means \\[display-time] should display day and date as well as time.")
37
38(defvar display-time-process nil)
39
40(defvar display-time-interval 60
41  "*Seconds between updates of time in the mode line.")
42
43(defvar display-time-24hr-format nil
44  "*Non-nill indicates time should be displayed as hh:mm, 0 <= hh <= 23.
45Nil means 1 <= hh <= 12, and an AM/PM suffix is used.")
46
47(defvar display-time-string nil)
48
49(defvar display-time-hook nil
50  "* List of functions to be called when the time is updated on the mode line.")
51
52(defvar display-time-server-down-time nil
53   "Time when mail file's file system was recorded to be down.
54If that file system seems to be up, the value is nil.")
55
56;;;###autoload
57(defun display-time ()
58  "Display current time, load level, and mail flag in mode line of each buffer.
59Updates automatically every minute.
60If `display-time-day-and-date' is non-nil, the current day and date
61are displayed as well.
62After each update, `display-time-hook' is run with `run-hooks'."
63  (interactive)
64  (let ((live (and display-time-process
65		   (eq (process-status display-time-process) 'run))))
66    (if (not live)
67	(progn
68	  (if display-time-process
69	      (delete-process display-time-process))
70	  (or global-mode-string (setq global-mode-string '("")))
71	  (or (memq 'display-time-string global-mode-string)
72	      (setq global-mode-string
73		    (append global-mode-string '(display-time-string))))
74	  (setq display-time-string "")
75	  ;; Using a pty is wasteful, and the separate session causes
76	  ;; annoyance sometimes (some systems kill idle sessions).
77	  (let ((process-connection-type nil))
78	    (setq display-time-process
79		  (start-process "display-time" nil
80				 (expand-file-name "wakeup" exec-directory)
81				 (int-to-string display-time-interval))))
82	  (process-kill-without-query display-time-process)
83	  (set-process-sentinel display-time-process 'display-time-sentinel)
84	  (set-process-filter display-time-process 'display-time-filter)))))
85
86(defun display-time-sentinel (proc reason)
87  (or (eq (process-status proc) 'run)
88      (setq display-time-string ""))
89  ;; Force mode-line updates
90  (save-excursion (set-buffer (other-buffer)))
91  (set-buffer-modified-p (buffer-modified-p))
92  (sit-for 0))
93
94(defun display-time-filter (proc string)
95  (let ((time (current-time-string))
96	(load (condition-case ()
97		  (if (zerop (car (load-average))) ""
98		    (let ((str (format " %03d" (car (load-average)))))
99		      (concat (substring str 0 -2) "." (substring str -2))))
100		(error "")))
101	(mail-spool-file (or display-time-mail-file
102			     (getenv "MAIL")
103			     (concat rmail-spool-directory
104				     (user-login-name))))
105	hour am-pm-flag mail-flag)
106    (setq hour (read (substring time 11 13)))
107    (if (not display-time-24hr-format)
108	(progn
109	  (setq am-pm-flag (if (>= hour 12) "pm" "am"))
110	  (if (> hour 12)
111	      (setq hour (- hour 12))
112	    (if (= hour 0)
113		(setq hour 12))))
114      (setq am-pm-flag ""))
115    (setq mail-flag
116	  (if (and (or (null display-time-server-down-time)
117		       ;; If have been down for 20 min, try again.
118		       (> (- (nth 1 (current-time))
119			     display-time-server-down-time)
120			  1200))
121		   (let ((start-time (current-time)))
122		     (prog1
123			 (display-time-file-nonempty-p mail-spool-file)
124		       (if (> (- (nth 1 (current-time)) (nth 1 start-time))
125			      20)
126			   ;; Record that mail file is not accessible.
127			   (setq display-time-server-down-time
128				 (nth 1 (current-time)))
129			 ;; Record that mail file is accessible.
130			 (setq display-time-server-down-time nil))
131		       )))
132	      " Mail"
133	    ""))
134    (setq display-time-string
135	  (concat (format "%d" hour) (substring time 13 16)
136		  am-pm-flag
137		  load
138		  mail-flag))
139    ;; Append the date if desired.
140    (if display-time-day-and-date
141	(setq display-time-string
142	      (concat (substring time 0 11) display-time-string))))
143  (run-hooks 'display-time-hook)
144  ;; Force redisplay of all buffers' mode lines to be considered.
145  (save-excursion (set-buffer (other-buffer)))
146  (set-buffer-modified-p (buffer-modified-p))
147  ;; Do redisplay right now, if no input pending.
148  (sit-for 0))
149
150(defun display-time-file-nonempty-p (file)
151  (and (file-exists-p file)
152       (< 0 (nth 7 (file-attributes (file-chase-links file))))))
153
154;;; time.el ends here
155