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 ((old-tz (getenv "TZ"))
 160         gmt nyt)
 161     (unwind-protect
 162         (progn
 163           (setenv "TZ" "America/New_York")
 164           (setq nyt (format-time-string "%z"))
 165           (setenv "TZ" "Europe/London")
 166           (setq gmt (format-time-string "%z")))
 167       (setenv "TZ" old-tz))
 168     (if (string-equal nyt gmt)
 169         legacy-style-world-list
 170       zoneinfo-style-world-list))
 171   "Alist of time zones and places for `display-time-world' to display.
 172 Each element has the form (TIMEZONE LABEL).
 173 TIMEZONE should be in a format supported by your system.  See the
 174 documentation of `zoneinfo-style-world-list' and
 175 \`legacy-style-world-list' for two widely used formats.  LABEL is
 176 a string to display as the label of that TIMEZONE's time."
 177   :group 'display-time
 178   :type '(repeat (list string string))
 179   :version "23.1")
 180
 181 (defcustom display-time-world-time-format "%A %d %B %R %Z"
 182   "Format of the time displayed, see `format-time-string'."
 183   :group 'display-time
 184   :type 'string
 185   :version "23.1")
 186
 187 (defcustom display-time-world-buffer-name "*wclock*"
 188   "Name of the world clock buffer."
 189   :group 'display-time
 190   :type 'string
 191   :version "23.1")
 192
 193 (defcustom display-time-world-timer-enable t
 194   "If non-nil, a timer will update the world clock."
 195   :group 'display-time
 196   :type 'boolean
 197   :version "23.1")
 198
 199 (defcustom display-time-world-timer-second 60
 200   "Interval in seconds for updating the world clock."
 201   :group 'display-time
 202   :type 'integer
 203   :version "23.1")
 204
 205 (defvar display-time-world-mode-map
 206   (let ((map (make-sparse-keymap)))
 207     (define-key map "q" 'kill-this-buffer)
 208     map)
 209   "Keymap of Display Time World mode.")
 210
 211 ;;;###autoload
 212 (defun display-time ()
 213   "Enable display of time, load level, and mail flag in mode lines.
 214 This display updates automatically every minute.
 215 If `display-time-day-and-date' is non-nil, the current day and date
 216 are displayed as well.
 217 This runs the normal hook `display-time-hook' after each update."
 218   (interactive)
 219   (display-time-mode 1))
 220
 221 ;; This business used to be simpler when all mode lines had the same
 222 ;; face and the image could just be pbm.  Now we try to rely on an xpm
 223 ;; image with a transparent background.  Otherwise, set the background
 224 ;; for pbm.
 225
 226 (defcustom display-time-mail-face nil
 227   "Face to use for `display-time-mail-string'.
 228 If `display-time-use-mail-icon' is non-nil, the image's
 229 background color is the background of this face.  Set this to
 230 make the mail indicator stand out on a color display."
 231   :group 'mode-line-faces
 232   :group 'display-time
 233   :version "22.1"
 234   :type '(choice (const :tag "None" nil) face))
 235
 236 (defvar display-time-mail-icon
 237   (find-image '((:type xpm :file "letter.xpm" :ascent center)
 238                 (:type pbm :file "letter.pbm" :ascent center)))
 239   "Image specification to offer as the mail indicator on a graphic display.
 240 See `display-time-use-mail-icon' and `display-time-mail-face'.")
 241
 242 ;; Fixme: Default to icon on graphical display?
 243 (defcustom display-time-use-mail-icon nil
 244   "Non-nil means use an icon as mail indicator on a graphic display.
 245 Otherwise use `display-time-mail-string'.  The icon may consume less
 246 of the mode line.  It is specified by `display-time-mail-icon'."
 247   :group 'display-time
 248   :type 'boolean)
 249
 250 ;; Fixme: maybe default to the character if we can display Unicode.
 251 (defcustom display-time-mail-string "Mail"
 252   "String to use as the mail indicator in `display-time-string-forms'.
 253 This can use the Unicode letter character if you can display it."
 254   :group 'display-time
 255   :version "22.1"
 256   :type '(choice (const "Mail")
 257                  ;; Use :tag here because the Lucid menu won't display
 258                  ;; multibyte text.
 259                  (const :tag "Unicode letter character" "✉")
 260                  string))
 261
 262 (defcustom display-time-format nil
 263   "String specifying format for displaying the time in the mode line.
 264 See the function `format-time-string' for an explanation of
 265 how to write this string.  If this is nil, the defaults
 266 depend on `display-time-day-and-date' and `display-time-24hr-format'."
 267   :type '(choice (const :tag "Default" nil)
 268                  string)
 269   :group 'display-time)
 270
 271 (defcustom display-time-string-forms
 272   '((if (and (not display-time-format) display-time-day-and-date)
 273         (format-time-string "%a %b %e " now)
 274       "")
 275     (propertize
 276      (format-time-string (or display-time-format
 277                              (if display-time-24hr-format "%H:%M" "%-I:%M%p"))
 278                          now)
 279      'help-echo (format-time-string "%a %b %e, %Y" now))
 280     load
 281     (if mail
 282         ;; Build the string every time to act on customization.
 283         ;; :set-after doesn't help for `customize-option'.  I think it
 284         ;; should.
 285         (concat
 286          " "
 287          (propertize
 288           display-time-mail-string
 289           'display `(when (and display-time-use-mail-icon
 290                                (display-graphic-p))
 291                       ,@display-time-mail-icon
 292                       ,@(if (and display-time-mail-face
 293                                  (memq (plist-get (cdr display-time-mail-icon)
 294                                                   :type)
 295                                        '(pbm xbm)))
 296                             (let ((bg (face-attribute display-time-mail-face
 297                                                       :background)))
 298                               (if (stringp bg)
 299                                   (list :background bg)))))
 300           'face display-time-mail-face
 301           'help-echo "You have new mail; mouse-2: Read mail"
 302           'mouse-face 'mode-line-highlight
 303           'local-map (make-mode-line-mouse-map 'mouse-2
 304                                                read-mail-command)))
 305       ""))
 306   "List of expressions governing display of the time in the mode line.
 307 For most purposes, you can control the time format using `display-time-format'
 308 which is a more standard interface.
 309
 310 This expression is a list of expressions that can involve the keywords
 311 `load', `day', `month', and `year', `12-hours', `24-hours', `minutes',
 312 `seconds', all numbers in string form, and `monthname', `dayname', `am-pm',
 313 and `time-zone' all alphabetic strings, and `mail' a true/nil value.
 314
 315 For example, the form
 316
 317   '((substring year -2) \"/\" month \"/\" day
 318     \" \" 24-hours \":\" minutes \":\" seconds
 319     (if time-zone \" (\") time-zone (if time-zone \")\")
 320     (if mail \" Mail\" \"\"))
 321
 322 would give mode line times like `94/12/30 21:07:48 (UTC)'."
 323   :type 'sexp
 324   :group 'display-time)
 325
 326 (defun display-time-event-handler ()
 327   (display-time-update)
 328   ;; Do redisplay right now, if no input pending.
 329   (sit-for 0)
 330   (let* ((current (current-time))
 331          (timer display-time-timer)
 332          ;; Compute the time when this timer will run again, next.
 333          (next-time (timer-relative-time
 334                      (list (aref timer 1) (aref timer 2) (aref timer 3))
 335                      (* 5 (aref timer 4)) 0)))
 336     ;; If the activation time is far in the past,
 337     ;; skip executions until we reach a time in the future.
 338     ;; This avoids a long pause if Emacs has been suspended for hours.
 339     (or (> (nth 0 next-time) (nth 0 current))
 340         (and (= (nth 0 next-time) (nth 0 current))
 341              (> (nth 1 next-time) (nth 1 current)))
 342         (and (= (nth 0 next-time) (nth 0 current))
 343              (= (nth 1 next-time) (nth 1 current))
 344              (> (nth 2 next-time) (nth 2 current)))
 345         (progn
 346           (timer-set-time timer (timer-next-integral-multiple-of-time
 347                                  current display-time-interval)
 348                           display-time-interval)
 349           (timer-activate timer)))))
 350
 351 (defun display-time-next-load-average ()
 352   (interactive)
 353   (if (= 3 (setq display-time-load-average (1+ display-time-load-average)))
 354       (setq display-time-load-average 0))
 355   (display-time-update)
 356   (sit-for 0))
 357
 358 (defun display-time-mail-check-directory ()
 359   (let ((mail-files (directory-files display-time-mail-directory t))
 360         (size 0))
 361     (while (and mail-files (= size 0))
 362       ;; Count size of regular files only.
 363       (setq size (+ size (or (and (file-regular-p (car mail-files))
 364                                   (nth 7 (file-attributes (car mail-files))))
 365                              0)))
 366       (setq mail-files (cdr mail-files)))
 367     (if (> size 0)
 368         size
 369       nil)))
 370
 371 (with-no-warnings
 372   ;; Warnings are suppresed to avoid "global/dynamic var `X' lacks a prefix".
 373   (defvar now)
 374   (defvar time)
 375   (defvar load)
 376   (defvar mail)
 377   (defvar 24-hours)
 378   (defvar hour)
 379   (defvar 12-hours)
 380   (defvar am-pm)
 381   (defvar minutes)
 382   (defvar seconds)
 383   (defvar time-zone)
 384   (defvar day)
 385   (defvar year)
 386   (defvar monthname)
 387   (defvar month)
 388   (defvar dayname))
 389
 390 (defun display-time-update ()
 391   "Update the display-time info for the mode line.
 392 However, don't redisplay right now.
 393
 394 This is used for things like Rmail `g' that want to force an
 395 update which can wait for the next redisplay."
 396   (let* ((now (current-time))
 397          (time (current-time-string now))
 398          (load (if (null display-time-load-average)
 399                    ""
 400                  (condition-case ()
 401                      ;; Do not show values less than
 402                      ;; `display-time-load-average-threshold'.
 403                      (if (> (* display-time-load-average-threshold 100)
 404                             (nth display-time-load-average (load-average)))
 405                          ""
 406                        ;; The load average number is mysterious, so
 407                        ;; provide some help.
 408                        (let ((str (format " %03d"
 409                                           (nth display-time-load-average
 410                                                (load-average)))))
 411                          (propertize
 412                           (concat (substring str 0 -2) "." (substring str -2))
 413                           'local-map (make-mode-line-mouse-map
 414                                       'mouse-2 'display-time-next-load-average)
 415                           'mouse-face 'mode-line-highlight
 416                           'help-echo (concat
 417                                       "System load average for past "
 418                                       (if (= 0 display-time-load-average)
 419                                           "1 minute"
 420                                         (if (= 1 display-time-load-average)
 421                                             "5 minutes"
 422                                           "15 minutes"))
 423                                       "; mouse-2: next"))))
 424                    (error ""))))
 425          (mail-spool-file (or display-time-mail-file
 426                               (getenv "MAIL")
 427                               (concat rmail-spool-directory
 428                                       (user-login-name))))
 429          (mail (cond
 430                 (display-time-mail-function
 431                  (funcall display-time-mail-function))
 432                 (display-time-mail-directory
 433                  (display-time-mail-check-directory))
 434                 ((and (stringp mail-spool-file)
 435                       (or (null display-time-server-down-time)
 436                           ;; If have been down for 20 min, try again.
 437                           (> (- (nth 1 now) display-time-server-down-time)
 438                              1200)
 439                           (and (< (nth 1 now) display-time-server-down-time)
 440                                (> (- (nth 1 now)
 441                                      display-time-server-down-time)
 442                                   -64336))))
 443                  (let ((start-time (current-time)))
 444                    (prog1
 445                        (display-time-file-nonempty-p mail-spool-file)
 446                      (if (> (- (nth 1 (current-time))
 447                                (nth 1 start-time))
 448                             20)
 449                          ;; Record that mail file is not accessible.
 450                          (setq display-time-server-down-time
 451                                (nth 1 (current-time)))
 452                        ;; Record that mail file is accessible.
 453                        (setq display-time-server-down-time nil)))))))
 454          (24-hours (substring time 11 13))
 455          (hour (string-to-number 24-hours))
 456          (12-hours (int-to-string (1+ (% (+ hour 11) 12))))
 457          (am-pm (if (>= hour 12) "pm" "am"))
 458          (minutes (substring time 14 16))
 459          (seconds (substring time 17 19))
 460          (time-zone (car (cdr (current-time-zone now))))
 461          (day (substring time 8 10))
 462          (year (substring time 20 24))
 463          (monthname (substring time 4 7))
 464          (month
 465           (cdr
 466            (assoc
 467             monthname
 468             '(("Jan" . "1") ("Feb" . "2") ("Mar" . "3") ("Apr" . "4")
 469               ("May" . "5") ("Jun" . "6") ("Jul" . "7") ("Aug" . "8")
 470               ("Sep" . "9") ("Oct" . "10") ("Nov" . "11") ("Dec" . "12")))))
 471          (dayname (substring time 0 3)))
 472     (setq display-time-string
 473           (mapconcat 'eval display-time-string-forms ""))
 474     ;; This is inside the let binding, but we are not going to document
 475     ;; what variables are available.
 476     (run-hooks 'display-time-hook))
 477   (force-mode-line-update))
 478
 479 (defun display-time-file-nonempty-p (file)
 480   (let ((remote-file-name-inhibit-cache (- display-time-interval 5)))
 481     (and (file-exists-p file)
 482          (< 0 (nth 7 (file-attributes (file-chase-links file)))))))
 483
 484 ;;;###autoload
 485 (define-minor-mode display-time-mode
 486   "Toggle display of time, load level, and mail flag in mode lines.
 487 With a prefix argument ARG, enable Display Time mode if ARG is
 488 positive, and disable it otherwise.  If called from Lisp, enable
 489 it if ARG is omitted or nil.
 490
 491 When Display Time mode is enabled, it updates every minute (you
 492 can control the number of seconds between updates by customizing
 493 `display-time-interval').  If `display-time-day-and-date' is
 494 non-nil, the current day and date are displayed as well.  This
 495 runs the normal hook `display-time-hook' after each update."
 496   :global t :group 'display-time
 497   (and display-time-timer (cancel-timer display-time-timer))
 498   (setq display-time-timer nil)
 499   (setq display-time-string "")
 500   (or global-mode-string (setq global-mode-string '("")))
 501   (setq display-time-load-average display-time-default-load-average)
 502   (if display-time-mode
 503       (progn
 504         (or (memq 'display-time-string global-mode-string)
 505             (setq global-mode-string
 506                   (append global-mode-string '(display-time-string))))
 507         ;; Set up the time timer.
 508         (setq display-time-timer
 509               (run-at-time t display-time-interval
 510                            'display-time-event-handler))
 511         ;; Make the time appear right away.
 512         (display-time-update)
 513         ;; When you get new mail, clear "Mail" from the mode line.
 514         (add-hook 'rmail-after-get-new-mail-hook
 515                   'display-time-event-handler))
 516     (remove-hook 'rmail-after-get-new-mail-hook
 517                  'display-time-event-handler)))
 518
 519
 520 (define-derived-mode display-time-world-mode nil "World clock"
 521   "Major mode for buffer that displays times in various time zones.
 522 See `display-time-world'."
 523   (setq show-trailing-whitespace nil))
 524
 525 (defun display-time-world-display (alist)
 526   "Replace current buffer text with times in various zones, based on ALIST."
 527   (let ((inhibit-read-only t)
 528         (buffer-undo-list t)
 529         (old-tz (getenv "TZ"))
 530         (max-width 0)
 531         result fmt)
 532     (erase-buffer)
 533     (unwind-protect
 534         (dolist (zone alist)
 535           (let* ((label (cadr zone))
 536                  (width (string-width label)))
 537             (setenv "TZ" (car zone))
 538             (push (cons label
 539                         (format-time-string display-time-world-time-format))
 540                   result)
 541             (when (> width max-width)
 542               (setq max-width width))))
 543       (setenv "TZ" old-tz))
 544     (setq fmt (concat "%-" (int-to-string max-width) "s %s\n"))
 545     (dolist (timedata (nreverse result))
 546       (insert (format fmt (car timedata) (cdr timedata)))))
 547   (delete-char -1))
 548
 549 ;;;###autoload
 550 (defun display-time-world ()
 551   "Enable updating display of times in various time zones.
 552 `display-time-world-list' specifies the zones.
 553 To turn off the world time display, go to that window and type `q'."
 554   (interactive)
 555   (when (and display-time-world-timer-enable
 556              (not (get-buffer display-time-world-buffer-name)))
 557     (run-at-time t display-time-world-timer-second 'display-time-world-timer))
 558   (with-current-buffer (get-buffer-create display-time-world-buffer-name)
 559     (display-time-world-display display-time-world-list))
 560   (pop-to-buffer display-time-world-buffer-name)
 561   (fit-window-to-buffer)
 562   (display-time-world-mode))
 563
 564 (defun display-time-world-timer ()
 565   (if (get-buffer display-time-world-buffer-name)
 566       (with-current-buffer (get-buffer display-time-world-buffer-name)
 567         (display-time-world-display display-time-world-list))
 568     ;; cancel timer
 569     (let ((list timer-list))
 570       (while list
 571         (let ((elt (pop list)))
 572           (when (equal (symbol-name (aref elt 5)) "display-time-world-timer")
 573             (cancel-timer elt)))))))
 574
 575 ;;;###autoload
 576 (defun emacs-uptime (&optional format)
 577   "Return a string giving the uptime of this instance of Emacs.
 578 FORMAT is a string to format the result, using `format-seconds'.
 579 For example, the Unix uptime command format is \"%D, %z%2h:%.2m\"."
 580   (interactive)
 581   (let ((str
 582          (format-seconds (or format "%Y, %D, %H, %M, %z%S")
 583                          (float-time
 584                           (time-subtract (current-time) before-init-time)))))
 585     (if (called-interactively-p 'interactive)
 586         (message "%s" str)
 587       str)))
 588
 589 ;;;###autoload
 590 (defun emacs-init-time ()
 591   "Return a string giving the duration of the Emacs initialization."
 592   (interactive)
 593   (let ((str
 594          (format "%.1f seconds"
 595                  (float-time
 596                   (time-subtract after-init-time before-init-time)))))
 597     (if (called-interactively-p 'interactive)
 598         (message "%s" str)
 599       str)))
 600
 601 (provide 'time)
 602
 603 ;;; time.el ends here