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