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, 2000-2014 Free Software
   4 ;; Foundation, Inc.
   5
   6 ;; Maintainer: emacs-devel@gnu.org
   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 the past 1 minute,
  68 past 5 or 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   nil => None (do not display the load average)"
  75   :type '(choice (const :tag "1 minute load" 0)
  76                  (const :tag "5 minutes load" 1)
  77                  (const :tag "15 minutes load" 2)
  78                  (const :tag "None" nil))
  79   :group 'display-time)
  80
  81 (defvar display-time-load-average nil
  82   "Value of the system's load average currently shown on the mode line.
  83 See `display-time-default-load-average'.
  84
  85 This is an internal variable; setting it has no effect.")
  86
  87 (defcustom display-time-load-average-threshold 0.1
  88   "Load-average values below this value won't be shown in the mode line."
  89   :type 'number
  90   :group 'display-time)
  91
  92 ;;;###autoload
  93 (defcustom display-time-day-and-date nil "\
  94 Non-nil means \\[display-time] should display day and date as well as time."
  95   :type 'boolean
  96   :group 'display-time)
  97
  98 (defvar display-time-timer nil)
  99
 100 (defcustom display-time-interval 60
 101   "Seconds between updates of time in the mode line."
 102   :type 'integer
 103   :group 'display-time)
 104
 105 (defcustom display-time-24hr-format nil
 106   "Non-nil indicates time should be displayed as hh:mm, 0 <= hh <= 23.
 107 A value of nil means 1 <= hh <= 12, and an AM/PM suffix is used."
 108   :type 'boolean
 109   :group 'display-time)
 110
 111 (defvar display-time-string nil)
 112 ;;;###autoload(put 'display-time-string 'risky-local-variable t)
 113
 114 (defcustom display-time-hook nil
 115   "List of functions to be called when the time is updated on the mode line."
 116   :type 'hook
 117   :group 'display-time)
 118
 119 (defvar display-time-server-down-time nil
 120    "Time when mail file's file system was recorded to be down.
 121 If that file system seems to be up, the value is nil.")
 122
 123 (defcustom zoneinfo-style-world-list
 124   '(("America/Los_Angeles" "Seattle")
 125     ("America/New_York" "New York")
 126     ("Europe/London" "London")
 127     ("Europe/Paris" "Paris")
 128     ("Asia/Calcutta" "Bangalore")
 129     ("Asia/Tokyo" "Tokyo"))
 130   "Alist of zoneinfo-style time zones and places for `display-time-world'.
 131 Each element has the form (TIMEZONE LABEL).
 132 TIMEZONE should be a string of the form AREA/LOCATION, where AREA is
 133 the name of a region -- a continent or ocean, and LOCATION is the name
 134 of a specific location, e.g., a city, within that region.
 135 LABEL is a string to display as the label of that TIMEZONE's time."
 136   :group 'display-time
 137   :type '(repeat (list string string))
 138   :version "23.1")
 139
 140 (defcustom legacy-style-world-list
 141   '(("PST8PDT" "Seattle")
 142     ("EST5EDT" "New York")
 143     ("GMT0BST" "London")
 144     ("CET-1CDT" "Paris")
 145     ("IST-5:30" "Bangalore")
 146     ("JST-9" "Tokyo"))
 147   "Alist of traditional-style time zones and places for `display-time-world'.
 148 Each element has the form (TIMEZONE LABEL).
 149 TIMEZONE should be a string of the form:
 150
 151      std[+|-]offset[dst[offset][,date[/time],date[/time]]]
 152
 153 See the documentation of the TZ environment variable on your system,
 154 for more details about the format of TIMEZONE.
 155 LABEL is a string to display as the label of that TIMEZONE's time."
 156   :group 'display-time
 157   :type '(repeat (list string string))
 158   :version "23.1")
 159
 160 (defcustom display-time-world-list
 161   ;; Determine if zoneinfo style timezones are supported by testing that
 162   ;; America/New York and Europe/London return different timezones.
 163   (let ((old-tz (getenv "TZ"))
 164         gmt nyt)
 165     (unwind-protect
 166         (progn
 167           (setenv "TZ" "America/New_York")
 168           (setq nyt (format-time-string "%z"))
 169           (setenv "TZ" "Europe/London")
 170           (setq gmt (format-time-string "%z")))
 171       (setenv "TZ" old-tz))
 172     (if (string-equal nyt gmt)
 173         legacy-style-world-list
 174       zoneinfo-style-world-list))
 175   "Alist of time zones and places for `display-time-world' to display.
 176 Each element has the form (TIMEZONE LABEL).
 177 TIMEZONE should be in a format supported by your system.  See the
 178 documentation of `zoneinfo-style-world-list' and
 179 \`legacy-style-world-list' for two widely used formats.  LABEL is
 180 a string to display as the label of that TIMEZONE's time."
 181   :group 'display-time
 182   :type '(repeat (list string string))
 183   :version "23.1")
 184
 185 (defcustom display-time-world-time-format "%A %d %B %R %Z"
 186   "Format of the time displayed, see `format-time-string'."
 187   :group 'display-time
 188   :type 'string
 189   :version "23.1")
 190
 191 (defcustom display-time-world-buffer-name "*wclock*"
 192   "Name of the world clock buffer."
 193   :group 'display-time
 194   :type 'string
 195   :version "23.1")
 196
 197 (defcustom display-time-world-timer-enable t
 198   "If non-nil, a timer will update the world clock."
 199   :group 'display-time
 200   :type 'boolean
 201   :version "23.1")
 202
 203 (defcustom display-time-world-timer-second 60
 204   "Interval in seconds for updating the world clock."
 205   :group 'display-time
 206   :type 'integer
 207   :version "23.1")
 208
 209 ;;;###autoload
 210 (defun display-time ()
 211   "Enable display of time, load level, and mail flag in mode lines.
 212 This display updates automatically every minute.
 213 If `display-time-day-and-date' is non-nil, the current day and date
 214 are displayed as well.
 215 This runs the normal hook `display-time-hook' after each update."
 216   (interactive)
 217   (display-time-mode 1))
 218
 219 ;; This business used to be simpler when all mode lines had the same
 220 ;; face and the image could just be pbm.  Now we try to rely on an xpm
 221 ;; image with a transparent background.  Otherwise, set the background
 222 ;; for pbm.
 223
 224 (defcustom display-time-mail-face nil
 225   "Face to use for `display-time-mail-string'.
 226 If `display-time-use-mail-icon' is non-nil, the image's
 227 background color is the background of this face.  Set this to
 228 make the mail indicator stand out on a color display."
 229   :group 'mode-line-faces
 230   :group 'display-time
 231   :version "22.1"
 232   :type '(choice (const :tag "None" nil) face))
 233
 234 (defvar display-time-mail-icon
 235   (find-image '((:type xpm :file "letter.xpm" :ascent center)
 236                 (:type pbm :file "letter.pbm" :ascent center)))
 237   "Image specification to offer as the mail indicator on a graphic display.
 238 See `display-time-use-mail-icon' and `display-time-mail-face'.")
 239
 240 ;; Fixme: Default to icon on graphical display?
 241 (defcustom display-time-use-mail-icon nil
 242   "Non-nil means use an icon as mail indicator on a graphic display.
 243 Otherwise use `display-time-mail-string'.  The icon may consume less
 244 of the mode line.  It is specified by `display-time-mail-icon'."
 245   :group 'display-time
 246   :type 'boolean)
 247
 248 ;; Fixme: maybe default to the character if we can display Unicode.
 249 (defcustom display-time-mail-string "Mail"
 250   "String to use as the mail indicator in `display-time-string-forms'.
 251 This can use the Unicode letter character if you can display it."
 252   :group 'display-time
 253   :version "22.1"
 254   :type '(choice (const "Mail")
 255                  ;; Use :tag here because the Lucid menu won't display
 256                  ;; multibyte text.
 257                  (const :tag "Unicode letter character" "✉")
 258                  string))
 259
 260 (defcustom display-time-format nil
 261   "String specifying format for displaying the time in the mode line.
 262 See the function `format-time-string' for an explanation of
 263 how to write this string.  If this is nil, the defaults
 264 depend on `display-time-day-and-date' and `display-time-24hr-format'."
 265   :type '(choice (const :tag "Default" nil)
 266                  string)
 267   :group 'display-time)
 268
 269 (defcustom display-time-string-forms
 270   '((if (and (not display-time-format) display-time-day-and-date)
 271         (format-time-string "%a %b %e " now)
 272       "")
 273     (propertize
 274      (format-time-string (or display-time-format
 275                              (if display-time-24hr-format "%H:%M" "%-I:%M%p"))
 276                          now)
 277      'help-echo (format-time-string "%a %b %e, %Y" now))
 278     load
 279     (if mail
 280         ;; Build the string every time to act on customization.
 281         ;; :set-after doesn't help for `customize-option'.  I think it
 282         ;; should.
 283         (concat
 284          " "
 285          (propertize
 286           display-time-mail-string
 287           'display `(when (and display-time-use-mail-icon
 288                                (display-graphic-p))
 289                       ,@display-time-mail-icon
 290                       ,@(if (and display-time-mail-face
 291                                  (memq (plist-get (cdr display-time-mail-icon)
 292                                                   :type)
 293                                        '(pbm xbm)))
 294                             (let ((bg (face-attribute display-time-mail-face
 295                                                       :background)))
 296                               (if (stringp bg)
 297                                   (list :background bg)))))
 298           'face display-time-mail-face
 299           'help-echo "You have new mail; mouse-2: Read mail"
 300           'mouse-face 'mode-line-highlight
 301           'local-map (make-mode-line-mouse-map 'mouse-2
 302                                                read-mail-command)))
 303       ""))
 304   "List of expressions governing display of the time in the mode line.
 305 For most purposes, you can control the time format using `display-time-format'
 306 which is a more standard interface.
 307
 308 This expression is a list of expressions that can involve the keywords
 309 `load', `day', `month', and `year', `12-hours', `24-hours', `minutes',
 310 `seconds', all numbers in string form, and `monthname', `dayname', `am-pm',
 311 and `time-zone' all alphabetic strings, and `mail' a true/nil value.
 312
 313 For example, the form
 314
 315   '((substring year -2) \"/\" month \"/\" day
 316     \" \" 24-hours \":\" minutes \":\" seconds
 317     (if time-zone \" (\") time-zone (if time-zone \")\")
 318     (if mail \" Mail\" \"\"))
 319
 320 would give mode line times like `94/12/30 21:07:48 (UTC)'."
 321   :type 'sexp
 322   :group 'display-time)
 323
 324 (defun display-time-event-handler ()
 325   (display-time-update)
 326   (let* ((current (current-time))
 327          (timer display-time-timer)
 328          ;; Compute the time when this timer will run again, next.
 329          (next-time (timer-relative-time
 330                      (list (aref timer 1) (aref timer 2) (aref timer 3))
 331                      (* 5 (aref timer 4)) 0)))
 332     ;; If the activation time is far in the past,
 333     ;; skip executions until we reach a time in the future.
 334     ;; This avoids a long pause if Emacs has been suspended for hours.
 335     (or (> (nth 0 next-time) (nth 0 current))
 336         (and (= (nth 0 next-time) (nth 0 current))
 337              (> (nth 1 next-time) (nth 1 current)))
 338         (and (= (nth 0 next-time) (nth 0 current))
 339              (= (nth 1 next-time) (nth 1 current))
 340              (> (nth 2 next-time) (nth 2 current)))
 341         (progn
 342           (timer-set-time timer (timer-next-integral-multiple-of-time
 343                                  current display-time-interval)
 344                           display-time-interval)
 345           (timer-activate timer)))))
 346
 347 (defun display-time-next-load-average ()
 348   "Switch between different load averages in the mode line.
 349 Switches from the 1 to 5 to 15 minute load average, and then back to 1."
 350   (interactive)
 351   (if (= 3 (setq display-time-load-average (1+ display-time-load-average)))
 352       (setq display-time-load-average 0))
 353   (display-time-update))
 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 (with-no-warnings
 369   ;; Warnings are suppressed to avoid "global/dynamic var `X' lacks a prefix".
 370   (defvar now)
 371   (defvar time)
 372   (defvar load)
 373   (defvar mail)
 374   (defvar 24-hours)
 375   (defvar hour)
 376   (defvar 12-hours)
 377   (defvar am-pm)
 378   (defvar minutes)
 379   (defvar seconds)
 380   (defvar time-zone)
 381   (defvar day)
 382   (defvar year)
 383   (defvar monthname)
 384   (defvar month)
 385   (defvar dayname))
 386
 387 (defun display-time-update ()
 388   "Update the display-time info for the mode line.
 389 However, don't redisplay right now.
 390
 391 This is used for things like Rmail `g' that want to force an
 392 update which can wait for the next redisplay."
 393   (let* ((now (current-time))
 394          (time (current-time-string now))
 395          (load (if (null display-time-load-average)
 396                    ""
 397                  (condition-case ()
 398                      ;; Do not show values less than
 399                      ;; `display-time-load-average-threshold'.
 400                      (if (> (* display-time-load-average-threshold 100)
 401                             (nth display-time-load-average (load-average)))
 402                          ""
 403                        ;; The load average number is mysterious, so
 404                        ;; provide some help.
 405                        (let ((str (format " %03d"
 406                                           (nth display-time-load-average
 407                                                (load-average)))))
 408                          (propertize
 409                           (concat (substring str 0 -2) "." (substring str -2))
 410                           'local-map (make-mode-line-mouse-map
 411                                       'mouse-2 'display-time-next-load-average)
 412                           'mouse-face 'mode-line-highlight
 413                           'help-echo (concat
 414                                       "System load average for past "
 415                                       (if (= 0 display-time-load-average)
 416                                           "1 minute"
 417                                         (if (= 1 display-time-load-average)
 418                                             "5 minutes"
 419                                           "15 minutes"))
 420                                       "; mouse-2: next"))))
 421                    (error ""))))
 422          (mail-spool-file (or display-time-mail-file
 423                               (getenv "MAIL")
 424                               (concat rmail-spool-directory
 425                                       (user-login-name))))
 426          (mail (cond
 427                 (display-time-mail-function
 428                  (funcall display-time-mail-function))
 429                 (display-time-mail-directory
 430                  (display-time-mail-check-directory))
 431                 ((and (stringp mail-spool-file)
 432                       (or (null display-time-server-down-time)
 433                           ;; If have been down for 20 min, try again.
 434                           (> (- (nth 1 now) display-time-server-down-time)
 435                              1200)
 436                           (and (< (nth 1 now) display-time-server-down-time)
 437                                (> (- (nth 1 now)
 438                                      display-time-server-down-time)
 439                                   -64336))))
 440                  (let ((start-time (current-time)))
 441                    (prog1
 442                        (display-time-file-nonempty-p mail-spool-file)
 443                      (if (> (- (nth 1 (current-time))
 444                                (nth 1 start-time))
 445                             20)
 446                          ;; Record that mail file is not accessible.
 447                          (setq display-time-server-down-time
 448                                (nth 1 (current-time)))
 449                        ;; Record that mail file is accessible.
 450                        (setq display-time-server-down-time nil)))))))
 451          (24-hours (substring time 11 13))
 452          (hour (string-to-number 24-hours))
 453          (12-hours (int-to-string (1+ (% (+ hour 11) 12))))
 454          (am-pm (if (>= hour 12) "pm" "am"))
 455          (minutes (substring time 14 16))
 456          (seconds (substring time 17 19))
 457          (time-zone (car (cdr (current-time-zone now))))
 458          (day (substring time 8 10))
 459          (year (format-time-string "%Y" now))
 460          (monthname (substring time 4 7))
 461          (month
 462           (cdr
 463            (assoc
 464             monthname
 465             '(("Jan" . "1") ("Feb" . "2") ("Mar" . "3") ("Apr" . "4")
 466               ("May" . "5") ("Jun" . "6") ("Jul" . "7") ("Aug" . "8")
 467               ("Sep" . "9") ("Oct" . "10") ("Nov" . "11") ("Dec" . "12")))))
 468          (dayname (substring time 0 3)))
 469     (setq display-time-string
 470           (mapconcat 'eval display-time-string-forms ""))
 471     ;; This is inside the let binding, but we are not going to document
 472     ;; what variables are available.
 473     (run-hooks 'display-time-hook))
 474   (force-mode-line-update 'all))
 475
 476 (defun display-time-file-nonempty-p (file)
 477   (let ((remote-file-name-inhibit-cache (- display-time-interval 5)))
 478     (and (file-exists-p file)
 479          (< 0 (nth 7 (file-attributes (file-chase-links file)))))))
 480
 481 ;;;###autoload
 482 (define-minor-mode display-time-mode
 483   "Toggle display of time, load level, and mail flag in mode lines.
 484 With a prefix argument ARG, enable Display Time mode if ARG is
 485 positive, and disable it otherwise.  If called from Lisp, enable
 486 it if ARG is omitted or nil.
 487
 488 When Display Time mode is enabled, it updates every minute (you
 489 can control the number of seconds between updates by customizing
 490 `display-time-interval').  If `display-time-day-and-date' is
 491 non-nil, the current day and date are displayed as well.  This
 492 runs the normal hook `display-time-hook' after each update."
 493   :global t :group 'display-time
 494   (and display-time-timer (cancel-timer display-time-timer))
 495   (setq display-time-timer nil)
 496   (setq display-time-string "")
 497   (or global-mode-string (setq global-mode-string '("")))
 498   (setq display-time-load-average display-time-default-load-average)
 499   (if display-time-mode
 500       (progn
 501         (or (memq 'display-time-string global-mode-string)
 502             (setq global-mode-string
 503                   (append global-mode-string '(display-time-string))))
 504         ;; Set up the time timer.
 505         (setq display-time-timer
 506               (run-at-time t display-time-interval
 507                            'display-time-event-handler))
 508         ;; Make the time appear right away.
 509         (display-time-update)
 510         ;; When you get new mail, clear "Mail" from the mode line.
 511         (add-hook 'rmail-after-get-new-mail-hook
 512                   'display-time-event-handler))
 513     (remove-hook 'rmail-after-get-new-mail-hook
 514                  'display-time-event-handler)))
 515
 516
 517 (define-derived-mode display-time-world-mode special-mode "World clock"
 518   "Major mode for buffer that displays times in various time zones.
 519 See `display-time-world'."
 520   (setq show-trailing-whitespace nil))
 521
 522 (defun display-time-world-display (alist)
 523   "Replace current buffer text with times in various zones, based on ALIST."
 524   (let ((inhibit-read-only t)
 525         (buffer-undo-list t)
 526         (old-tz (getenv "TZ"))
 527         (max-width 0)
 528         result fmt)
 529     (erase-buffer)
 530     (unwind-protect
 531         (dolist (zone alist)
 532           (let* ((label (cadr zone))
 533                  (width (string-width label)))
 534             (setenv "TZ" (car zone))
 535             (push (cons label
 536                         (format-time-string display-time-world-time-format))
 537                   result)
 538             (when (> width max-width)
 539               (setq max-width width))))
 540       (setenv "TZ" old-tz))
 541     (setq fmt (concat "%-" (int-to-string max-width) "s %s\n"))
 542     (dolist (timedata (nreverse result))
 543       (insert (format fmt (car timedata) (cdr timedata))))
 544     (delete-char -1)))
 545
 546 ;;;###autoload
 547 (defun display-time-world ()
 548   "Enable updating display of times in various time zones.
 549 `display-time-world-list' specifies the zones.
 550 To turn off the world time display, go to that window and type `q'."
 551   (interactive)
 552   (when (and display-time-world-timer-enable
 553              (not (get-buffer display-time-world-buffer-name)))
 554     (run-at-time t display-time-world-timer-second 'display-time-world-timer))
 555   (with-current-buffer (get-buffer-create display-time-world-buffer-name)
 556     (display-time-world-display display-time-world-list)
 557     (display-buffer display-time-world-buffer-name
 558                     (cons nil '((window-height . fit-window-to-buffer))))
 559     (display-time-world-mode)))
 560
 561 (defun display-time-world-timer ()
 562   (if (get-buffer display-time-world-buffer-name)
 563       (with-current-buffer (get-buffer display-time-world-buffer-name)
 564         (display-time-world-display display-time-world-list))
 565     ;; cancel timer
 566     (let ((list timer-list))
 567       (while list
 568         (let ((elt (pop list)))
 569           (when (equal (symbol-name (timer--function elt))
 570                        "display-time-world-timer")
 571             (cancel-timer elt)))))))
 572
 573 ;;;###autoload
 574 (defun emacs-uptime (&optional format)
 575   "Return a string giving the uptime of this instance of Emacs.
 576 FORMAT is a string to format the result, using `format-seconds'.
 577 For example, the Unix uptime command format is \"%D, %z%2h:%.2m\"."
 578   (interactive)
 579   (let ((str
 580          (format-seconds (or format "%Y, %D, %H, %M, %z%S")
 581                          (float-time
 582                           (time-subtract (current-time) before-init-time)))))
 583     (if (called-interactively-p 'interactive)
 584         (message "%s" str)
 585       str)))
 586
 587 ;;;###autoload
 588 (defun emacs-init-time ()
 589   "Return a string giving the duration of the Emacs initialization."
 590   (interactive)
 591   (let ((str
 592          (format "%.1f seconds"
 593                  (float-time
 594                   (time-subtract after-init-time before-init-time)))))
 595     (if (called-interactively-p 'interactive)
 596         (message "%s" str)
 597       str)))
 598
 599 (provide 'time)
 600
 601 ;;; time.el ends here