summaryrefslogtreecommitdiff
path: root/lisp/time.el
blob: fe3df1f99ac37f84952b84bb96cefc0519b650bf (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
;;; time.el --- display time and load in mode line of Emacs.

;; Copyright (C) 1985, 1986, 1987, 1993 Free Software Foundation, Inc.

;; Maintainer: FSF

;; This file is part of GNU Emacs.

;; GNU Emacs is free software; you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation; either version 2, or (at your option)
;; any later version.

;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;; GNU General Public License for more details.

;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs; see the file COPYING.  If not, write to
;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.

;;; Commentary:

;;; Facilities to display current time/date and a new-mail indicator
;;; in the Emacs mode line.  The single entry point is `display-time'.

;;; Code:

(defvar display-time-mail-file nil
  "*File name of mail inbox file, for indicating existence of new mail.
Default is system-dependent, and is the same as used by Rmail.")

;;;###autoload
(defvar display-time-day-and-date nil "\
*Non-nil means \\[display-time] should display day and date as well as time.")

(defvar display-time-process nil)

(defvar display-time-interval 60
  "*Seconds between updates of time in the mode line.")

(defvar display-time-24hr-format nil
  "*Non-nill indicates time should be displayed as hh:mm, 0 <= hh <= 23.
Nil means 1 <= hh <= 12, and an AM/PM suffix is used.")

(defvar display-time-string nil)

(defvar display-time-hook nil
  "* List of functions to be called when the time is updated on the mode line.")

(defvar display-time-server-down-time nil
   "Time when mail file's file system was recorded to be down.
If that file system seems to be up, the value is nil.")

;;;###autoload
(defun display-time ()
  "Display current time, load level, and mail flag in mode line of each buffer.
Updates automatically every minute.
If `display-time-day-and-date' is non-nil, the current day and date
are displayed as well.
After each update, `display-time-hook' is run with `run-hooks'."
  (interactive)
  (let ((live (and display-time-process
		   (eq (process-status display-time-process) 'run))))
    (if (not live)
	(progn
	  (if display-time-process
	      (delete-process display-time-process))
	  (or global-mode-string (setq global-mode-string '("")))
	  (or (memq 'display-time-string global-mode-string)
	      (setq global-mode-string
		    (append global-mode-string '(display-time-string))))
	  (setq display-time-string "")
	  (setq display-time-process
		(start-process "display-time" nil
			       (expand-file-name "wakeup" exec-directory)
			       (int-to-string display-time-interval)))
	  (process-kill-without-query display-time-process)
	  (set-process-sentinel display-time-process 'display-time-sentinel)
	  (set-process-filter display-time-process 'display-time-filter)))))

(defun display-time-sentinel (proc reason)
  (or (eq (process-status proc) 'run)
      (setq display-time-string ""))
  ;; Force mode-line updates
  (save-excursion (set-buffer (other-buffer)))
  (set-buffer-modified-p (buffer-modified-p))
  (sit-for 0))

(defun display-time-filter (proc string)
  (let ((time (current-time-string))
	(load (condition-case ()
		  (if (zerop (car (load-average))) ""
		    (let ((str (format " %03d" (car (load-average)))))
		      (concat (substring str 0 -2) "." (substring str -2))))
		(error "")))
	(mail-spool-file (or display-time-mail-file
			     (getenv "MAIL")
			     (concat rmail-spool-directory
				     (user-login-name))))
	hour am-pm-flag mail-flag)
    (setq hour (read (substring time 11 13)))
    (if (not display-time-24hr-format)
	(progn
	  (setq am-pm-flag (if (>= hour 12) "pm" "am"))
	  (if (> hour 12)
	      (setq hour (- hour 12))
	    (if (= hour 0)
		(setq hour 12))))
      (setq am-pm-flag ""))
    (setq mail-flag
	  (if (and (or (null display-time-server-down-time)
		       ;; If have been down for 20 min, try again.
		       (> (- (nth 1 (current-time))
			     display-time-server-down-time)
			  1200))
		   (let ((start-time (current-time)))
		     (prog1
			 (display-time-file-nonempty-p mail-spool-file)
		       (if (> (- (nth 1 (current-time)) (nth 1 start-time))
			      20)
			   ;; Record that mail file is not accessible.
			   (setq display-time-server-down-time 
				 (nth 1 (current-time)))
			 ;; Record that mail file is accessible.
			 (setq display-time-server-down-time nil))
		       )))
	      " Mail"
	    ""))
    (setq display-time-string
	  (concat (format "%d" hour) (substring time 13 16)
		  am-pm-flag
		  load
		  mail-flag))
    ;; Append the date if desired.
    (if display-time-day-and-date
	(setq display-time-string
	      (concat (substring time 0 11) display-time-string))))
  (run-hooks 'display-time-hook)
  ;; Force redisplay of all buffers' mode lines to be considered.
  (save-excursion (set-buffer (other-buffer)))
  (set-buffer-modified-p (buffer-modified-p))
  ;; Do redisplay right now, if no input pending.
  (sit-for 0))

(defun display-time-file-nonempty-p (file)
  (and (file-exists-p file)
       (< 0 (nth 7 (file-attributes (file-chase-links file))))))

;;; time.el ends here