lisp/time.el

   1 ;;; time.el --- display time, load and mail indicator in mode line of Emacs -*-coding: utf-8 -*-
   2
   3 ;; Copyright (C) 1985-1987, 1993-1994, 1996, 2000-2011
   4 ;;   Free Software Foundation, Inc.
   5
   6 ;; Maintainer: FSF
   7
   8 ;; This file is part of GNU Emacs.
   9
  10 ;; GNU Emacs is free software: you can redistribute it and/or modify
  11 ;; it under the terms of the GNU General Public License as published by
  12 ;; the Free Software Foundation, either version 3 of the License, or
  13 ;; (at your option) any later version.
  14
  15 ;; GNU Emacs is distributed in the hope that it will be useful,
  16 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 ;; GNU General Public License for more details.
  19
  20 ;; You should have received a copy of the GNU General Public License
  21 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  22
  23 ;;; Commentary:
  24
  25 ;; Facilities to display current time/date and a new-mail indicator
  26 ;; in the Emacs mode line.  The entry point is `display-time'.
  27
  28 ;; Display time world in a buffer, the entry point is
  29 ;; `display-time-world'.
  30
  31 ;;; Code:
  32
  33 (defgroup display-time nil
  34   "Display time and load in mode line of Emacs."
  35   :group 'mode-line
  36   :group 'mail)
  37
  38
  39 (defcustom display-time-mail-file nil
  40   "File name of mail inbox file, for indicating existence of new mail.
  41 Non-nil and not a string means don't check for mail; nil means use
  42 default, which is system-dependent, and is the same as used by Rmail."
  43   :type '(choice (const :tag "None" none)
  44                  (const :tag "Default" nil)
  45                  (file :format "%v"))
  46   :group 'display-time)
  47
  48 (defcustom display-time-mail-directory nil
  49   "Name of mail inbox directory, for indicating existence of new mail.
  50 Any nonempty regular file in the directory is regarded as newly arrived mail.
  51 If nil, do not check a directory for arriving mail."
  52   :type '(choice (const :tag "None" nil)
  53                  (directory :format "%v"))
  54   :group 'display-time)
  55
  56 (defcustom display-time-mail-function nil
  57   "Function to call, for indicating existence of new mail.
  58 If nil, that means use the default method: check that the file
  59 specified by `display-time-mail-file' is nonempty or that the
  60 directory `display-time-mail-directory' contains nonempty files."
  61   :type '(choice (const :tag "Default" nil)
  62                  (function))
  63   :group 'display-time)
  64
  65 (defcustom display-time-default-load-average 0
  66   "Which load average value will be shown in the mode line.
  67 Almost every system can provide values of load for past 1 minute, past 5 or
  68 past 15 minutes.  The default is to display 1 minute load average.
  69 The value can be one of:
  70
  71   0   => 1 minute load
  72   1   => 5 minutes load
  73   2   => 15 minutes load"
  74   :type '(choice (const :tag "1 minute load" 0)
  75                  (const :tag "5 minutes load" 1)
  76                  (const :tag "15 minutes load" 2)
  77                  (const :tag "None" nil))
  78   :group 'display-time)
  79
  80 (defvar display-time-load-average nil
  81   "Load average currently being shown in mode line.")
  82
  83 (defcustom display-time-load-average-threshold 0.1
  84   "Load-average values below this value won't be shown in the mode line."
  85   :type 'number
  86   :group 'display-time)
  87
  88 ;;;###autoload
  89 (defcustom display-time-day-and-date nil "\
  90 Non-nil means \\[display-time] should display day and date as well as time."
  91   :type 'boolean
  92   :group 'display-time)
  93
  94 (defvar display-time-timer nil)
  95
  96 (defcustom display-time-interval 60
  97   "Seconds between updates of time in the mode line."
  98   :type 'integer
  99   :group 'display-time)
 100
 101 (defcustom display-time-24hr-format nil
 102   "Non-nil indicates time should be displayed as hh:mm, 0 <= hh <= 23.
 103 A value of nil means 1 <= hh <= 12, and an AM/PM suffix is used."
 104   :type 'boolean
 105   :group 'display-time)
 106
 107 (defvar display-time-string nil)
 108 ;;;###autoload(put 'display-time-string 'risky-local-variable t)
 109
 110 (defcustom display-time-hook nil
 111   "List of functions to be called when the time is updated on the mode line."
 112   :type 'hook
 113   :group 'display-time)
 114
 115 (defvar display-time-server-down-time nil
 116    "Time when mail file's file system was recorded to be down.
 117 If that file system seems to be up, the value is nil.")
 118
 119 (defcustom zoneinfo-style-world-list
 120   '(("America/Los_Angeles" "Seattle")
 121     ("America/New_York" "New York")
 122     ("Europe/London" "London")
 123     ("Europe/Paris" "Paris")
 124     ("Asia/Calcutta" "Bangalore")
 125     ("Asia/Tokyo" "Tokyo"))
 126   "Alist of zoneinfo-style time zones and places for `display-time-world'.
 127 Each element has the form (TIMEZONE LABEL).
 128 TIMEZONE should be a string of the form AREA/LOCATION, where AREA is
 129 the name of a region -- a continent or ocean, and LOCATION is the name
 130 of a specific location, e.g., a city, within that region.
 131 LABEL is a string to display as the label of that TIMEZONE's time."
 132   :group 'display-time
 133   :type '(repeat (list string string))
 134   :version "23.1")
 135
 136 (defcustom legacy-style-world-list
 137   '(("PST8PDT" "Seattle")
 138     ("EST5EDT" "New York")
 139     ("GMT0BST" "London")
 140     ("CET-1CDT" "Paris")
 141     ("IST-5:30" "Bangalore")
 142     ("JST-9" "Tokyo"))
 143   "Alist of traditional-style time zones and places for `display-time-world'.
 144 Each element has the form (TIMEZONE LABEL).
 145 TIMEZONE should be a string of the form:
 146
 147      std[+|-]offset[dst[offset][,date[/time],date[/time]]]
 148
 149 See the documentation of the TZ environment variable on your system,
 150 for more details about the format of TIMEZONE.
 151 LABEL is a string to display as the label of that TIMEZONE's time."
 152   :group 'display-time
 153   :type '(repeat (list string string))
 154   :version "23.1")
 155
 156 (defcustom display-time-world-list
 157   ;; Determine if zoneinfo style timezones are supported by testing that
 158   ;; America/New York and Europe/London return different timezones.
 159   (let (gmt nyt)
 160     (set-time-zone-rule "America/New_York")
 161     (setq nyt (format-time-string "%z"))
 162     (set-time-zone-rule "Europe/London")
 163     (setq gmt (format-time-string "%z"))
 164     (set-time-zone-rule nil)
 165     (if (string-equal nyt gmt)
 166         legacy-style-world-list
 167       zoneinfo-style-world-list))
 168   "Alist of time zones and places for `display-time-world' to display.
 169 Each element has the form (TIMEZONE LABEL).
 170 TIMEZONE should be in the format supported by `set-time-zone-rule' on
 171 your system.  See the documentation of `zoneinfo-style-world-list' and
 172 \`legacy-style-world-list' for two widely used formats.
 173 LABEL is a string to display as the label of that TIMEZONE's time."
 174   :group 'display-time
 175   :type '(repeat (list string string))
 176   :version "23.1")
 177
 178 (defcustom display-time-world-time-format "%A %d %B %R %Z"
 179   "Format of the time displayed, see `format-time-string'."
 180   :group 'display-time
 181   :type 'string
 182   :version "23.1")
 183
 184 (defcustom display-time-world-buffer-name "*wclock*"
 185   "Name of the world clock buffer."
 186   :group 'display-time
 187   :type 'string
 188   :version "23.1")
 189
 190 (defcustom display-time-world-timer-enable t
 191   "If non-nil, a timer will update the world clock."
 192   :group 'display-time
 193   :type 'boolean
 194   :version "23.1")
 195
 196 (defcustom display-time-world-timer-second 60
 197   "Interval in seconds for updating the world clock."
 198   :group 'display-time
 199   :type 'integer
 200   :version "23.1")
 201
 202 (defvar display-time-world-mode-map
 203   (let ((map (make-sparse-keymap)))
 204     (define-key map "q" 'kill-this-buffer)
 205     map)
 206   "Keymap of Display Time World mode.")
 207
 208 ;;;###autoload
 209 (defun display-time ()
 210   "Enable display of time, load level, and mail flag in mode lines.
 211 This display updates automatically every minute.
 212 If `display-time-day-and-date' is non-nil, the current day and date
 213 are displayed as well.
 214 This runs the normal hook `display-time-hook' after each update."
 215   (interactive)
 216   (display-time-mode 1))
 217
 218 ;; This business used to be simpler when all mode lines had the same
 219 ;; face and the image could just be pbm.  Now we try to rely on an xpm
 220 ;; image with a transparent background.  Otherwise, set the background
 221 ;; for pbm.
 222
 223 (defcustom display-time-mail-face nil
 224   "Face to use for `display-time-mail-string'.
 225 If `display-time-use-mail-icon' is non-nil, the image's
 226 background color is the background of this face.  Set this to
 227 make the mail indicator stand out on a color display."
 228   :group 'mode-line-faces
 229   :group 'display-time
 230   :version "22.1"
 231   :type '(choice (const :tag "None" nil) face))
 232
 233 (defvar display-time-mail-icon
 234   (find-image '((:type xpm :file "letter.xpm" :ascent center)
 235                 (:type pbm :file "letter.pbm" :ascent center)))
 236   "Image specification to offer as the mail indicator on a graphic display.
 237 See `display-time-use-mail-icon' and `display-time-mail-face'.")
 238
 239 ;; Fixme: Default to icon on graphical display?
 240 (defcustom display-time-use-mail-icon nil
 241   "Non-nil means use an icon as mail indicator on a graphic display.
 242 Otherwise use `display-time-mail-string'.  The icon may consume less
 243 of the mode line.  It is specified by `display-time-mail-icon'."
 244   :group 'display-time
 245   :type 'boolean)
 246
 247 ;; Fixme: maybe default to the character if we can display Unicode.
 248 (defcustom display-time-mail-string "Mail"
 249   "String to use as the mail indicator in `display-time-string-forms'.
 250 This can use the Unicode letter character if you can display it."
 251   :group 'display-time
 252   :version "22.1"
 253   :type '(choice (const "Mail")
 254                  ;; Use :tag here because the Lucid menu won't display
 255                  ;; multibyte text.
 256                  (const :tag "Unicode letter character" "✉")
 257                  string))
 258
 259 (defcustom display-time-format nil
 260   "String specifying format for displaying the time in the mode line.
 261 See the function `format-time-string' for an explanation of
 262 how to write this string.  If this is nil, the defaults
 263 depend on `display-time-day-and-date' and `display-time-24hr-format'."
 264   :type '(choice (const :tag "Default" nil)
 265                  string)
 266   :group 'display-time)
 267
 268 (defcustom display-time-string-forms
 269   '((if (and (not display-time-format) display-time-day-and-date)
 270         (format-time-string "%a %b %e " now)
 271       "")
 272     (propertize
 273      (format-time-string (or display-time-format
 274                              (if display-time-24hr-format "%H:%M" "%-I:%M%p"))
 275                          now)
 276      'help-echo (format-time-string "%a %b %e, %Y" now))
 277     load
 278     (if mail
 279         ;; Build the string every time to act on customization.
 280         ;; :set-after doesn't help for `customize-option'.  I think it
 281         ;; should.
 282         (concat
 283          " "
 284          (propertize
 285           display-time-mail-string
 286           'display `(when (and display-time-use-mail-icon
 287                                (display-graphic-p))
 288                       ,@display-time-mail-icon
 289                       ,@(if (and display-time-mail-face
 290                                  (memq (plist-get (cdr display-time-mail-icon)
 291                                                   :type)
 292                                        '(pbm xbm)))
 293                             (let ((bg (face-attribute display-time-mail-face
 294                                                       :background)))
 295                               (if (stringp bg)
 296                                   (list :background bg)))))
 297           'face display-time-mail-face
 298           'help-echo "You have new mail; mouse-2: Read mail"
 299           'mouse-face 'mode-line-highlight
 300           'local-map (make-mode-line-mouse-map 'mouse-2
 301                                                read-mail-command)))
 302       ""))
 303   "List of expressions governing display of the time in the mode line.
 304 For most purposes, you can control the time format using `display-time-format'
 305 which is a more standard interface.
 306
 307 This expression is a list of expressions that can involve the keywords
 308 `load', `day', `month', and `year', `12-hours', `24-hours', `minutes',
 309 `seconds', all numbers in string form, and `monthname', `dayname', `am-pm',
 310 and `time-zone' all alphabetic strings, and `mail' a true/nil value.
 311
 312 For example, the form
 313
 314   '((substring year -2) \"/\" month \"/\" day
 315     \" \" 24-hours \":\" minutes \":\" seconds
 316     (if time-zone \" (\") time-zone (if time-zone \")\")
 317     (if mail \" Mail\" \"\"))
 318
 319 would give mode line times like `94/12/30 21:07:48 (UTC)'."
 320   :type 'sexp
 321   :group 'display-time)
 322
 323 (defun display-time-event-handler ()
 324   (display-time-update)
 325   ;; Do redisplay right now, if no input pending.
 326   (sit-for 0)
 327   (let* ((current (current-time))
 328          (timer display-time-timer)
 329          ;; Compute the time when this timer will run again, next.
 330          (next-time (timer-relative-time
 331                      (list (aref timer 1) (aref timer 2) (aref timer 3))
 332                      (* 5 (aref timer 4)) 0)))
 333     ;; If the activation time is far in the past,
 334     ;; skip executions until we reach a time in the future.
 335     ;; This avoids a long pause if Emacs has been suspended for hours.
 336     (or (> (nth 0 next-time) (nth 0 current))
 337         (and (= (nth 0 next-time) (nth 0 current))
 338              (> (nth 1 next-time) (nth 1 current)))
 339         (and (= (nth 0 next-time) (nth 0 current))
 340              (= (nth 1 next-time) (nth 1 current))
 341              (> (nth 2 next-time) (nth 2 current)))
 342         (progn
 343           (timer-set-time timer (timer-next-integral-multiple-of-time
 344                                  current display-time-interval)
 345                           display-time-interval)
 346           (timer-activate timer)))))
 347
 348 (defun display-time-next-load-average ()
 349   (interactive)
 350   (if (= 3 (setq display-time-load-average (1+ display-time-load-average)))
 351       (setq display-time-load-average 0))
 352   (display-time-update)
 353   (sit-for 0))
 354
 355 (defun display-time-mail-check-directory ()
 356   (let ((mail-files (directory-files display-time-mail-directory t))
 357         (size 0))
 358     (while (and mail-files (= size 0))
 359       ;; Count size of regular files only.
 360       (setq size (+ size (or (and (file-regular-p (car mail-files))
 361                                   (nth 7 (file-attributes (car mail-files))))
 362                              0)))
 363       (setq mail-files (cdr mail-files)))
 364     (if (> size 0)
 365         size
 366       nil)))
 367
 368 (defun display-time-update ()
 369   "Update the display-time info for the mode line.
 370 However, don't redisplay right now.
 371
 372 This is used for things like Rmail `g' that want to force an
 373 update which can wait for the next redisplay."
 374   (let* ((now (current-time))
 375          (time (current-time-string now))
 376          (load (if (null display-time-load-average)
 377                    ""
 378                  (condition-case ()
 379                      ;; Do not show values less than
 380                      ;; `display-time-load-average-threshold'.
 381                      (if (> (* display-time-load-average-threshold 100)
 382                             (nth display-time-load-average (load-average)))
 383                          ""
 384                        ;; The load average number is mysterious, so
 385                        ;; provide some help.
 386                        (let ((str (format " %03d"
 387                                           (nth display-time-load-average
 388                                                (load-average)))))
 389                          (propertize
 390                           (concat (substring str 0 -2) "." (substring str -2))
 391                           'local-map (make-mode-line-mouse-map
 392                                       'mouse-2 'display-time-next-load-average)
 393                           'mouse-face 'mode-line-highlight
 394                           'help-echo (concat
 395                                       "System load average for past "
 396                                       (if (= 0 display-time-load-average)
 397                                           "1 minute"
 398                                         (if (= 1 display-time-load-average)
 399                                             "5 minutes"
 400                                           "15 minutes"))
 401                                       "; mouse-2: next"))))
 402                    (error ""))))
 403          (mail-spool-file (or display-time-mail-file
 404                               (getenv "MAIL")
 405                               (concat rmail-spool-directory
 406                                       (user-login-name))))
 407          (mail (or (and display-time-mail-function
 408                         (funcall display-time-mail-function))
 409                    (and display-time-mail-directory
 410                         (display-time-mail-check-directory))
 411                    (and (stringp mail-spool-file)
 412                         (or (null display-time-server-down-time)
 413                             ;; If have been down for 20 min, try again.
 414                             (> (- (nth 1 now) display-time-server-down-time)
 415                                1200)
 416                             (and (< (nth 1 now) display-time-server-down-time)
 417                                  (> (- (nth 1 now)
 418                                        display-time-server-down-time)
 419                                     -64336)))
 420                         (let ((start-time (current-time)))
 421                           (prog1
 422                               (display-time-file-nonempty-p mail-spool-file)
 423                             (if (> (- (nth 1 (current-time))
 424                                       (nth 1 start-time))
 425                                    20)
 426                                 ;; Record that mail file is not accessible.
 427                                 (setq display-time-server-down-time
 428                                       (nth 1 (current-time)))
 429                               ;; Record that mail file is accessible.
 430                               (setq display-time-server-down-time nil)))))))
 431          (24-hours (substring time 11 13))
 432          (hour (string-to-number 24-hours))
 433          (12-hours (int-to-string (1+ (% (+ hour 11) 12))))
 434          (am-pm (if (>= hour 12) "pm" "am"))
 435          (minutes (substring time 14 16))
 436          (seconds (substring time 17 19))
 437          (time-zone (car (cdr (current-time-zone now))))
 438          (day (substring time 8 10))
 439          (year (substring time 20 24))
 440          (monthname (substring time 4 7))
 441          (month
 442           (cdr
 443            (assoc
 444             monthname
 445             '(("Jan" . "1") ("Feb" . "2") ("Mar" . "3") ("Apr" . "4")
 446               ("May" . "5") ("Jun" . "6") ("Jul" . "7") ("Aug" . "8")
 447               ("Sep" . "9") ("Oct" . "10") ("Nov" . "11") ("Dec" . "12")))))
 448          (dayname (substring time 0 3)))
 449     (setq display-time-string
 450           (mapconcat 'eval display-time-string-forms ""))
 451     ;; This is inside the let binding, but we are not going to document
 452     ;; what variables are available.
 453     (run-hooks 'display-time-hook))
 454   (force-mode-line-update))
 455
 456 (defun display-time-file-nonempty-p (file)
 457   (let ((remote-file-name-inhibit-cache (- display-time-interval 5)))
 458     (and (file-exists-p file)
 459          (< 0 (nth 7 (file-attributes (file-chase-links file)))))))
 460
 461 ;;;###autoload
 462 (define-minor-mode display-time-mode
 463   "Toggle display of time, load level, and mail flag in mode lines.
 464 With a numeric arg, enable this display if arg is positive.
 465
 466 When this display is enabled, it updates automatically every minute
 467 \(you can control the number of seconds between updates by
 468 customizing `display-time-interval').
 469 If `display-time-day-and-date' is non-nil, the current day and date
 470 are displayed as well.
 471 This runs the normal hook `display-time-hook' after each update."
 472   :global t :group 'display-time
 473   (and display-time-timer (cancel-timer display-time-timer))
 474   (setq display-time-timer nil)
 475   (setq display-time-string "")
 476   (or global-mode-string (setq global-mode-string '("")))
 477   (setq display-time-load-average display-time-default-load-average)
 478   (if display-time-mode
 479       (progn
 480         (or (memq 'display-time-string global-mode-string)
 481             (setq global-mode-string
 482                   (append global-mode-string '(display-time-string))))
 483         ;; Set up the time timer.
 484         (setq display-time-timer
 485               (run-at-time t display-time-interval
 486                            'display-time-event-handler))
 487         ;; Make the time appear right away.
 488         (display-time-update)
 489         ;; When you get new mail, clear "Mail" from the mode line.
 490         (add-hook 'rmail-after-get-new-mail-hook
 491                   'display-time-event-handler))
 492     (remove-hook 'rmail-after-get-new-mail-hook
 493                  'display-time-event-handler)))
 494
 495
 496 (define-derived-mode display-time-world-mode nil "World clock"
 497   "Major mode for buffer that displays times in various time zones.
 498 See `display-time-world'."
 499   (setq show-trailing-whitespace nil))
 500
 501 (defun display-time-world-display (alist)
 502   "Replace current buffer text with times in various zones, based on ALIST."
 503   (let ((inhibit-read-only t)
 504         (buffer-undo-list t))
 505     (erase-buffer)
 506     (let ((max-width 0)
 507           (result ())
 508           fmt)
 509       (unwind-protect
 510           (dolist (zone alist)
 511             (let* ((label (cadr zone))
 512                    (width (string-width label)))
 513               (set-time-zone-rule (car zone))
 514               (push (cons label
 515                           (format-time-string display-time-world-time-format))
 516                     result)
 517               (when (> width max-width)
 518                 (setq max-width width))))
 519         (set-time-zone-rule nil))
 520       (setq fmt (concat "%-" (int-to-string max-width) "s %s\n"))
 521       (dolist (timedata (nreverse result))
 522         (insert (format fmt (car timedata) (cdr timedata)))))
 523     (delete-char -1)))
 524
 525 ;;;###autoload
 526 (defun display-time-world ()
 527   "Enable updating display of times in various time zones.
 528 `display-time-world-list' specifies the zones.
 529 To turn off the world time display, go to that window and type `q'."
 530   (interactive)
 531   (when (and display-time-world-timer-enable
 532              (not (get-buffer display-time-world-buffer-name)))
 533     (run-at-time t display-time-world-timer-second 'display-time-world-timer))
 534   (with-current-buffer (get-buffer-create display-time-world-buffer-name)
 535     (display-time-world-display display-time-world-list))
 536   (pop-to-buffer display-time-world-buffer-name)
 537   (fit-window-to-buffer)
 538   (display-time-world-mode))
 539
 540 (defun display-time-world-timer ()
 541   (if (get-buffer display-time-world-buffer-name)
 542       (with-current-buffer (get-buffer display-time-world-buffer-name)
 543         (display-time-world-display display-time-world-list))
 544     ;; cancel timer
 545     (let ((list timer-list))
 546       (while list
 547         (let ((elt (pop list)))
 548           (when (equal (symbol-name (aref elt 5)) "display-time-world-timer")
 549             (cancel-timer elt)))))))
 550
 551 ;;;###autoload
 552 (defun emacs-uptime (&optional format)
 553   "Return a string giving the uptime of this instance of Emacs.
 554 FORMAT is a string to format the result, using `format-seconds'.
 555 For example, the Unix uptime command format is \"%D, %z%2h:%.2m\"."
 556   (interactive)
 557   (let ((str
 558          (format-seconds (or format "%Y, %D, %H, %M, %z%S")
 559                          (float-time
 560                           (time-subtract (current-time) before-init-time)))))
 561     (if (called-interactively-p 'interactive)
 562         (message "%s" str)
 563       str)))
 564
 565 ;;;###autoload
 566 (defun emacs-init-time ()
 567   "Return a string giving the duration of the Emacs initialization."
 568   (interactive)
 569   (let ((str
 570          (format "%.1f seconds"
 571                  (float-time
 572                   (time-subtract after-init-time before-init-time)))))
 573     (if (called-interactively-p 'interactive)
 574         (message "%s" str)
 575       str)))
 576
 577 (provide 'time)
 578
 579 ;;; time.el ends here