lisp/time.el

   1 ;;; time.el --- display time and load in mode line of Emacs.
   2
   3 ;; Copyright (C) 1985, 1986, 1987 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 ;;; Code:
  24
  25 (defvar display-time-mail-file nil
  26   "*File name of mail inbox file, for indicating existence of new mail.
  27 Default is system-dependent, and is the same as used by Rmail.")
  28
  29 ;;;###autoload
  30 (defconst display-time-day-and-date nil "\
  31 *Non-nil means \\[display-time] should display day and date as well as time.")
  32
  33 (defvar display-time-process nil)
  34
  35 (defvar display-time-interval 60
  36   "*Seconds between updates of time in the mode line.")
  37
  38 (defvar display-time-24hr-format nil
  39   "Non-nill indicates time should be displayed as hh:mm, 0 <= hh <= 23.
  40 Nil means 1 <= hh <= 12, and an AM/PM suffix is used.")
  41
  42 (defvar display-time-string nil)
  43
  44 (defvar display-time-hook nil
  45   "* List of functions to be called when the time is updated on the mode line.")
  46
  47 ;;;###autoload
  48 (defun display-time ()
  49   "Display current time and load level in mode line of each buffer.
  50 Updates automatically every minute.
  51 If `display-time-day-and-date' is non-nil, the current day and date
  52 are displayed as well.
  53 After each update, `display-time-hook' is run with `run-hooks'."
  54   (interactive)
  55   (let ((live (and display-time-process
  56                    (eq (process-status display-time-process) 'run))))
  57     (if (not live)
  58         (progn
  59           (if display-time-process
  60               (delete-process display-time-process))
  61           (or global-mode-string (setq global-mode-string '("")))
  62           (or (memq 'display-time-string global-mode-string)
  63               (setq global-mode-string
  64                     (append global-mode-string '(display-time-string))))
  65           (setq display-time-string "")
  66           (setq display-time-process
  67                 (start-process "display-time" nil
  68                                (concat exec-directory "wakeup")
  69                                (int-to-string display-time-interval)))
  70           (process-kill-without-query display-time-process)
  71           (set-process-sentinel display-time-process 'display-time-sentinel)
  72           (set-process-filter display-time-process 'display-time-filter)))))
  73
  74 (defun display-time-sentinel (proc reason)
  75   (or (eq (process-status proc) 'run)
  76       (setq display-time-string ""))
  77   ;; Force mode-line updates
  78   (save-excursion (set-buffer (other-buffer)))
  79   (set-buffer-modified-p (buffer-modified-p))
  80   (sit-for 0))
  81
  82 (defun display-time-filter (proc string)
  83   (let ((time (current-time-string))
  84         (load (condition-case ()
  85                   (if (zerop (car (load-average))) ""
  86                     (let ((str (format " %03d" (car (load-average)))))
  87                       (concat (substring str 0 -2) "." (substring str -2))))
  88                 (error "")))
  89         (mail-spool-file (or display-time-mail-file
  90                              (getenv "MAIL")
  91                              (concat rmail-spool-directory
  92                                      (or (getenv "LOGNAME")
  93                                          (getenv "USER")
  94                                          (user-login-name)))))
  95         hour am-pm-flag)
  96     (setq hour (read (substring time 11 13)))
  97     (if (not display-time-24hr-format)
  98         (progn
  99           (setq am-pm-flag (if (>= hour 12) "pm" "am"))
 100           (if (> hour 12)
 101               (setq hour (- hour 12))
 102             (if (= hour 0)
 103                 (setq hour 12))))
 104       (setq am-pm-flag ""))
 105     (setq display-time-string
 106           (concat (format "%d" hour) (substring time 13 16)
 107                   am-pm-flag
 108                   load
 109                   (if (and (file-exists-p mail-spool-file)
 110                            ;; file not empty?
 111                            (display-time-file-nonempty-p mail-spool-file))
 112                       " Mail"
 113                     "")))
 114     ;; Append the date if desired.
 115     (if display-time-day-and-date
 116         (setq display-time-string
 117               (concat (substring time 0 11) display-time-string))))
 118   (run-hooks 'display-time-hook)
 119   ;; Force redisplay of all buffers' mode lines to be considered.
 120   (save-excursion (set-buffer (other-buffer)))
 121   (set-buffer-modified-p (buffer-modified-p))
 122   ;; Do redisplay right now, if no input pending.
 123   (sit-for 0))
 124
 125 (defun display-time-file-nonempty-p (file)
 126   (while (file-symlink-p file)
 127     (setq file (file-symlink-p file)))
 128   (> (nth 7 (file-attributes file)) 0))
 129
 130 ;;; time.el ends here