lisp/time.el

   1 ;;; time.el --- display time, load and mail indicator in mode line of Emacs
   2
   3 ;; Copyright (C) 1985-1987, 1993-1994, 1996, 2000-2016 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 ((nyt (format-time-string "%z" nil "America/New_York"))
 164         (gmt (format-time-string "%z" nil "Europe/London")))
 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 a format supported by your system.  See the
 171 documentation of `zoneinfo-style-world-list' and
 172 `legacy-style-world-list' for two widely used formats.  LABEL is
 173 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 ;;;###autoload
 203 (defun display-time ()
 204   "Enable display of time, load level, and mail flag in mode lines.
 205 This display updates automatically every minute.
 206 If `display-time-day-and-date' is non-nil, the current day and date
 207 are displayed as well.
 208 This runs the normal hook `display-time-hook' after each update."
 209   (interactive)
 210   (display-time-mode 1))
 211
 212 ;; This business used to be simpler when all mode lines had the same
 213 ;; face and the image could just be pbm.  Now we try to rely on an xpm
 214 ;; image with a transparent background.  Otherwise, set the background
 215 ;; for pbm.
 216
 217 (defcustom display-time-mail-face nil
 218   "Face to use for `display-time-mail-string'.
 219 If `display-time-use-mail-icon' is non-nil, the image's
 220 background color is the background of this face.  Set this to
 221 make the mail indicator stand out on a color display."
 222   :group 'mode-line-faces
 223   :group 'display-time
 224   :version "22.1"
 225   :type '(choice (const :tag "None" nil) face))
 226
 227 (defvar display-time-mail-icon
 228   (find-image '((:type xpm :file "letter.xpm" :ascent center)
 229                 (:type pbm :file "letter.pbm" :ascent center)))
 230   "Image specification to offer as the mail indicator on a graphic display.
 231 See `display-time-use-mail-icon' and `display-time-mail-face'.")
 232
 233 ;; Fixme: Default to icon on graphical display?
 234 (defcustom display-time-use-mail-icon nil
 235   "Non-nil means use an icon as mail indicator on a graphic display.
 236 Otherwise use `display-time-mail-string'.  The icon may consume less
 237 of the mode line.  It is specified by `display-time-mail-icon'."
 238   :group 'display-time
 239   :type 'boolean)
 240
 241 ;; Fixme: maybe default to the character if we can display Unicode.
 242 (defcustom display-time-mail-string "Mail"
 243   "String to use as the mail indicator in `display-time-string-forms'.
 244 This can use the Unicode letter character if you can display it."
 245   :group 'display-time
 246   :version "22.1"
 247   :type '(choice (const "Mail")
 248                  ;; Use :tag here because the Lucid menu won't display
 249                  ;; multibyte text.
 250                  (const :tag "Unicode letter character" "✉")
 251                  string))
 252
 253 (defcustom display-time-format nil
 254   "String specifying format for displaying the time in the mode line.
 255 See the function `format-time-string' for an explanation of
 256 how to write this string.  If this is nil, the defaults
 257 depend on `display-time-day-and-date' and `display-time-24hr-format'."
 258   :type '(choice (const :tag "Default" nil)
 259                  string)
 260   :group 'display-time)
 261
 262 (defcustom display-time-string-forms
 263   '((if (and (not display-time-format) display-time-day-and-date)
 264         (format-time-string "%a %b %e " now)
 265       "")
 266     (propertize
 267      (format-time-string (or display-time-format
 268                              (if display-time-24hr-format "%H:%M" "%-I:%M%p"))
 269                          now)
 270      'help-echo (format-time-string "%a %b %e, %Y" now))
 271     load
 272     (if mail
 273         ;; Build the string every time to act on customization.
 274         ;; :set-after doesn't help for `customize-option'.  I think it
 275         ;; should.
 276         (concat
 277          " "
 278          (propertize
 279           display-time-mail-string
 280           'display `(when (and display-time-use-mail-icon
 281                                (display-graphic-p))
 282                       ,@display-time-mail-icon
 283                       ,@(if (and display-time-mail-face
 284                                  (memq (plist-get (cdr display-time-mail-icon)
 285                                                   :type)
 286                                        '(pbm xbm)))
 287                             (let ((bg (face-attribute display-time-mail-face
 288                                                       :background)))
 289                               (if (stringp bg)
 290                                   (list :background bg)))))
 291           'face display-time-mail-face
 292           'help-echo "You have new mail; mouse-2: Read mail"
 293           'mouse-face 'mode-line-highlight
 294           'local-map (make-mode-line-mouse-map 'mouse-2
 295                                                read-mail-command)))
 296       ""))
 297   "List of expressions governing display of the time in the mode line.
 298 For most purposes, you can control the time format using `display-time-format'
 299 which is a more standard interface.
 300
 301 This expression is a list of expressions that can involve the keywords
 302 `load', `day', `month', and `year', `12-hours', `24-hours', `minutes',
 303 `seconds', all numbers in string form, and `monthname', `dayname', `am-pm',
 304 and `time-zone' all alphabetic strings, and `mail' a true/nil value.
 305
 306 For example, the form
 307
 308   '((substring year -2) \"/\" month \"/\" day
 309     \" \" 24-hours \":\" minutes \":\" seconds
 310     (if time-zone \" (\") time-zone (if time-zone \")\")
 311     (if mail \" Mail\" \"\"))
 312
 313 would give mode line times like `94/12/30 21:07:48 (UTC)'."
 314   :type 'sexp
 315   :group 'display-time)
 316
 317 (defun display-time-event-handler ()
 318   (display-time-update)
 319   (let* ((current (current-time))
 320          (timer display-time-timer)
 321          ;; Compute the time when this timer will run again, next.
 322          (next-time (timer-relative-time
 323                      (list (aref timer 1) (aref timer 2) (aref timer 3))
 324                      (* 5 (aref timer 4)) 0)))
 325     ;; If the activation time is far in the past,
 326     ;; skip executions until we reach a time in the future.
 327     ;; This avoids a long pause if Emacs has been suspended for hours.
 328     (or (> (nth 0 next-time) (nth 0 current))
 329         (and (= (nth 0 next-time) (nth 0 current))
 330              (> (nth 1 next-time) (nth 1 current)))
 331         (and (= (nth 0 next-time) (nth 0 current))
 332              (= (nth 1 next-time) (nth 1 current))
 333              (> (nth 2 next-time) (nth 2 current)))
 334         (progn
 335           (timer-set-time timer (timer-next-integral-multiple-of-time
 336                                  current display-time-interval)
 337                           display-time-interval)
 338           (timer-activate timer)))))
 339
 340 (defun display-time-next-load-average ()
 341   "Switch between different load averages in the mode line.
 342 Switches from the 1 to 5 to 15 minute load average, and then back to 1."
 343   (interactive)
 344   (if (= 3 (setq display-time-load-average (1+ display-time-load-average)))
 345       (setq display-time-load-average 0))
 346   (display-time-update))
 347
 348 (defun display-time-mail-check-directory ()
 349   (let ((mail-files (directory-files display-time-mail-directory t))
 350         (size 0))
 351     (while (and mail-files (= size 0))
 352       ;; Count size of regular files only.
 353       (setq size (+ size (or (and (file-regular-p (car mail-files))
 354                                   (nth 7 (file-attributes (car mail-files))))
 355                              0)))
 356       (setq mail-files (cdr mail-files)))
 357     (if (> size 0)
 358         size
 359       nil)))
 360
 361 (with-no-warnings
 362   ;; Warnings are suppressed to avoid "global/dynamic var `X' lacks a prefix".
 363   (defvar now)
 364   (defvar time)
 365   (defvar load)
 366   (defvar mail)
 367   (defvar 24-hours)
 368   (defvar hour)
 369   (defvar 12-hours)
 370   (defvar am-pm)
 371   (defvar minutes)
 372   (defvar seconds)
 373   (defvar time-zone)
 374   (defvar day)
 375   (defvar year)
 376   (defvar monthname)
 377   (defvar month)
 378   (defvar dayname))
 379
 380 (defun display-time-update ()
 381   "Update the display-time info for the mode line.
 382 However, don't redisplay right now.
 383
 384 This is used for things like Rmail `g' that want to force an
 385 update which can wait for the next redisplay."
 386   (let* ((now (current-time))
 387          (time (current-time-string now))
 388          (load (if (null display-time-load-average)
 389                    ""
 390                  (condition-case ()
 391                      ;; Do not show values less than
 392                      ;; `display-time-load-average-threshold'.
 393                      (if (> (* display-time-load-average-threshold 100)
 394                             (nth display-time-load-average (load-average)))
 395                          ""
 396                        ;; The load average number is mysterious, so
 397                        ;; provide some help.
 398                        (let ((str (format " %03d"
 399                                           (nth display-time-load-average
 400                                                (load-average)))))
 401                          (propertize
 402                           (concat (substring str 0 -2) "." (substring str -2))
 403                           'local-map (make-mode-line-mouse-map
 404                                       'mouse-2 'display-time-next-load-average)
 405                           'mouse-face 'mode-line-highlight
 406                           'help-echo (concat
 407                                       "System load average for past "
 408                                       (if (= 0 display-time-load-average)
 409                                           "1 minute"
 410                                         (if (= 1 display-time-load-average)
 411                                             "5 minutes"
 412                                           "15 minutes"))
 413                                       "; mouse-2: next"))))
 414                    (error ""))))
 415          (mail-spool-file (or display-time-mail-file
 416                               (getenv "MAIL")
 417                               (concat rmail-spool-directory
 418                                       (user-login-name))))
 419          (mail (cond
 420                 (display-time-mail-function
 421                  (funcall display-time-mail-function))
 422                 (display-time-mail-directory
 423                  (display-time-mail-check-directory))
 424                 ((and (stringp mail-spool-file)
 425                       (or (null display-time-server-down-time)
 426                           ;; If have been down for 20 min, try again.
 427                           (> (- (nth 1 now) display-time-server-down-time)
 428                              1200)
 429                           (and (< (nth 1 now) display-time-server-down-time)
 430                                (> (- (nth 1 now)
 431                                      display-time-server-down-time)
 432                                   -64336))))
 433                  (let ((start-time (current-time)))
 434                    (prog1
 435                        (display-time-file-nonempty-p mail-spool-file)
 436                      (if (> (- (nth 1 (current-time))
 437                                (nth 1 start-time))
 438                             20)
 439                          ;; Record that mail file is not accessible.
 440                          (setq display-time-server-down-time
 441                                (nth 1 (current-time)))
 442                        ;; Record that mail file is accessible.
 443                        (setq display-time-server-down-time nil)))))))
 444          (24-hours (substring time 11 13))
 445          (hour (string-to-number 24-hours))
 446          (12-hours (int-to-string (1+ (% (+ hour 11) 12))))
 447          (am-pm (if (>= hour 12) "pm" "am"))
 448          (minutes (substring time 14 16))
 449          (seconds (substring time 17 19))
 450          (time-zone (car (cdr (current-time-zone now))))
 451          (day (substring time 8 10))
 452          (year (format-time-string "%Y" now))
 453          (monthname (substring time 4 7))
 454          (month
 455           (cdr
 456            (assoc
 457             monthname
 458             '(("Jan" . "1") ("Feb" . "2") ("Mar" . "3") ("Apr" . "4")
 459               ("May" . "5") ("Jun" . "6") ("Jul" . "7") ("Aug" . "8")
 460               ("Sep" . "9") ("Oct" . "10") ("Nov" . "11") ("Dec" . "12")))))
 461          (dayname (substring time 0 3)))
 462     (setq display-time-string
 463           (mapconcat 'eval display-time-string-forms ""))
 464     ;; This is inside the let binding, but we are not going to document
 465     ;; what variables are available.
 466     (run-hooks 'display-time-hook))
 467   (force-mode-line-update 'all))
 468
 469 (defun display-time-file-nonempty-p (file)
 470   (let ((remote-file-name-inhibit-cache (- display-time-interval 5)))
 471     (and (file-exists-p file)
 472          (< 0 (nth 7 (file-attributes (file-chase-links file)))))))
 473
 474 ;;;###autoload
 475 (define-minor-mode display-time-mode
 476   "Toggle display of time, load level, and mail flag in mode lines.
 477 With a prefix argument ARG, enable Display Time mode if ARG is
 478 positive, and disable it otherwise.  If called from Lisp, enable
 479 it if ARG is omitted or nil.
 480
 481 When Display Time mode is enabled, it updates every minute (you
 482 can control the number of seconds between updates by customizing
 483 `display-time-interval').  If `display-time-day-and-date' is
 484 non-nil, the current day and date are displayed as well.  This
 485 runs the normal hook `display-time-hook' after each update."
 486   :global t :group 'display-time
 487   (and display-time-timer (cancel-timer display-time-timer))
 488   (setq display-time-timer nil)
 489   (setq display-time-string "")
 490   (or global-mode-string (setq global-mode-string '("")))
 491   (setq display-time-load-average display-time-default-load-average)
 492   (if display-time-mode
 493       (progn
 494         (or (memq 'display-time-string global-mode-string)
 495             (setq global-mode-string
 496                   (append global-mode-string '(display-time-string))))
 497         ;; Set up the time timer.
 498         (setq display-time-timer
 499               (run-at-time t display-time-interval
 500                            'display-time-event-handler))
 501         ;; Make the time appear right away.
 502         (display-time-update)
 503         ;; When you get new mail, clear "Mail" from the mode line.
 504         (add-hook 'rmail-after-get-new-mail-hook
 505                   'display-time-event-handler))
 506     (remove-hook 'rmail-after-get-new-mail-hook
 507                  'display-time-event-handler)))
 508
 509
 510 (define-derived-mode display-time-world-mode special-mode "World clock"
 511   "Major mode for buffer that displays times in various time zones.
 512 See `display-time-world'."
 513   (setq show-trailing-whitespace nil))
 514
 515 (defun display-time-world-display (alist)
 516   "Replace current buffer text with times in various zones, based on ALIST."
 517   (let ((inhibit-read-only t)
 518         (buffer-undo-list t)
 519         (now (current-time))
 520         (max-width 0)
 521         result fmt)
 522     (erase-buffer)
 523     (dolist (zone alist)
 524       (let* ((label (cadr zone))
 525              (width (string-width label)))
 526         (push (cons label
 527                     (format-time-string display-time-world-time-format
 528                                         now (car zone)))
 529               result)
 530         (when (> width max-width)
 531           (setq max-width width))))
 532     (setq fmt (concat "%-" (int-to-string max-width) "s %s\n"))
 533     (dolist (timedata (nreverse result))
 534       (insert (format fmt (car timedata) (cdr timedata))))
 535     (delete-char -1)))
 536
 537 ;;;###autoload
 538 (defun display-time-world ()
 539   "Enable updating display of times in various time zones.
 540 `display-time-world-list' specifies the zones.
 541 To turn off the world time display, go to that window and type `q'."
 542   (interactive)
 543   (when (and display-time-world-timer-enable
 544              (not (get-buffer display-time-world-buffer-name)))
 545     (run-at-time t display-time-world-timer-second 'display-time-world-timer))
 546   (with-current-buffer (get-buffer-create display-time-world-buffer-name)
 547     (display-time-world-display display-time-world-list)
 548     (display-buffer display-time-world-buffer-name
 549                     (cons nil '((window-height . fit-window-to-buffer))))
 550     (display-time-world-mode)))
 551
 552 (defun display-time-world-timer ()
 553   (if (get-buffer display-time-world-buffer-name)
 554       (with-current-buffer (get-buffer display-time-world-buffer-name)
 555         (display-time-world-display display-time-world-list))
 556     ;; cancel timer
 557     (let ((list timer-list))
 558       (while list
 559         (let ((elt (pop list)))
 560           (when (equal (symbol-name (timer--function elt))
 561                        "display-time-world-timer")
 562             (cancel-timer elt)))))))
 563
 564 ;;;###autoload
 565 (defun emacs-uptime (&optional format)
 566   "Return a string giving the uptime of this instance of Emacs.
 567 FORMAT is a string to format the result, using `format-seconds'.
 568 For example, the Unix uptime command format is \"%D, %z%2h:%.2m\"."
 569   (interactive)
 570   (let ((str
 571          (format-seconds (or format "%Y, %D, %H, %M, %z%S")
 572                          (float-time
 573                           (time-subtract (current-time) before-init-time)))))
 574     (if (called-interactively-p 'interactive)
 575         (message "%s" str)
 576       str)))
 577
 578 ;;;###autoload
 579 (defun emacs-init-time ()
 580   "Return a string giving the duration of the Emacs initialization."
 581   (interactive)
 582   (let ((str
 583          (format "%.1f seconds"
 584                  (float-time
 585                   (time-subtract after-init-time before-init-time)))))
 586     (if (called-interactively-p 'interactive)
 587         (message "%s" str)
 588       str)))
 589
 590 (provide 'time)
 591
 592 ;;; time.el ends here