lisp/time.el

   1 ;; Display time and load in mode line of Emacs.
   2 ;; Copyright (C) 1985, 1986, 1987 Free Software Foundation, Inc.
   3
   4 ;; This file is part of GNU Emacs.
   5
   6 ;; GNU Emacs is free software; you can redistribute it and/or modify
   7 ;; it under the terms of the GNU General Public License as published by
   8 ;; the Free Software Foundation; either version 1, or (at your option)
   9 ;; any later version.
  10
  11 ;; GNU Emacs is distributed in the hope that it will be useful,
  12 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 ;; GNU General Public License for more details.
  15
  16 ;; You should have received a copy of the GNU General Public License
  17 ;; along with GNU Emacs; see the file COPYING.  If not, write to
  18 ;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
  19
  20
  21 (defvar display-time-mail-file nil
  22   "*File name of mail inbox file, for indicating existence of new mail.
  23 Default is system-dependent, and is the same as used by Rmail.")
  24
  25 (defvar display-time-process nil)
  26
  27 (defvar display-time-interval 60
  28   "*Seconds between updates of time in the mode line.")
  29
  30 (defvar display-time-string nil)
  31
  32 (defvar display-time-hook nil
  33   "* List of functions to be called when the time is updated on the mode line.")
  34
  35 (defun display-time ()
  36   "Display current time and load level in mode line of each buffer.
  37 Updates automatically every minute.
  38 If `display-time-day-and-date' is non-nil, the current day and date
  39 are displayed as well.
  40 After each update, `display-time-hook' is run with `run-hooks'."
  41   (interactive)
  42   (let ((live (and display-time-process
  43                    (eq (process-status display-time-process) 'run))))
  44     (if (not live)
  45         (progn
  46           (if display-time-process
  47               (delete-process display-time-process))
  48           (or global-mode-string (setq global-mode-string '("")))
  49           (or (memq 'display-time-string global-mode-string)
  50               (setq global-mode-string
  51                     (append global-mode-string '(display-time-string))))
  52           (setq display-time-string "")
  53           (setq display-time-process
  54                 (start-process "display-time" nil
  55                                "wakeup"
  56                                (int-to-string display-time-interval)))
  57           (process-kill-without-query display-time-process)
  58           (set-process-sentinel display-time-process 'display-time-sentinel)
  59           (set-process-filter display-time-process 'display-time-filter)))))
  60
  61 (defun display-time-sentinel (proc reason)
  62   (or (eq (process-status proc) 'run)
  63       (setq display-time-string ""))
  64   ;; Force mode-line updates
  65   (save-excursion (set-buffer (other-buffer)))
  66   (set-buffer-modified-p (buffer-modified-p))
  67   (sit-for 0))
  68
  69 (defun display-time-filter (proc string)
  70   (let ((time (current-time-string))
  71         (load (format "%03d" (car (load-average))))
  72         (mail-spool-file (or display-time-mail-file
  73                              (getenv "MAIL")
  74                              (concat rmail-spool-directory
  75                                      (or (getenv "LOGNAME")
  76                                          (getenv "USER")
  77                                          (user-login-name)))))
  78         hour pm)
  79     (setq hour (read (substring time 11 13)))
  80     (setq pm (>= hour 12))
  81     (if (> hour 12)
  82         (setq hour (- hour 12))
  83       (if (= hour 0)
  84           (setq hour 12)))
  85     (setq display-time-string
  86           (concat (format "%d" hour) (substring time 13 16)
  87                   (if pm "pm " "am ")
  88                   (substring load 0 -2) "." (substring load -2)
  89                   (if (and (file-exists-p mail-spool-file)
  90                            ;; file not empty?
  91                            (> (nth 7 (file-attributes mail-spool-file)) 0))
  92                       " Mail"
  93                     "")))
  94     ;; Append the date if desired.
  95     (if display-time-day-and-date
  96         (setq display-time-string
  97               (concat (substring time 0 11) display-time-string))))
  98   (run-hooks 'display-time-hook)
  99   ;; Force redisplay of all buffers' mode lines to be considered.
 100   (save-excursion (set-buffer (other-buffer)))
 101   (set-buffer-modified-p (buffer-modified-p))
 102   ;; Do redisplay right now, if no input pending.
 103   (sit-for 0))