summaryrefslogtreecommitdiff
path: root/lisp/battery.el
blob: a3be2fe4b880faa9cd126cd8792196ef2dea0c70 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
;;; battery.el --- display battery status information  -*- coding: iso-8859-1 -*-

;; Copyright (C) 1997-1998, 2000-2012 Free Software Foundation, Inc.

;; Author: Ralph Schleicher <rs@nunatak.allgaeu.org>
;; Keywords: hardware

;; This file is part of GNU Emacs.

;; GNU Emacs is free software: you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.

;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;; GNU General Public License for more details.

;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.

;;; Commentary:

;; There is at present support for GNU/Linux, OS X and Windows.  This
;; library supports both the `/proc/apm' file format of Linux version
;; 1.3.58 or newer and the `/proc/acpi/' directory structure of Linux
;; 2.4.20 and 2.6.  Darwin (OS X) is supported by using the `pmset'
;; program.  Windows is supported by the GetSystemPowerStatus API call.

;;; Code:

(require 'timer)
(eval-when-compile (require 'cl))


(defgroup battery nil
  "Display battery status information."
  :prefix "battery-"
  :group 'hardware)

(defcustom battery-status-function
  (cond ((and (eq system-type 'gnu/linux)
	      (file-readable-p "/proc/apm"))
	 'battery-linux-proc-apm)
	((and (eq system-type 'gnu/linux)
	      (file-directory-p "/proc/acpi/battery"))
	 'battery-linux-proc-acpi)
	((and (eq system-type 'gnu/linux)
	      (file-directory-p "/sys/class/power_supply/")
	      (directory-files "/sys/class/power_supply/" nil "BAT[0-9]$"))
	 'battery-linux-sysfs)
	((and (eq system-type 'gnu/linux)
	      (file-directory-p "/sys/class/power_supply/yeeloong-bat/")
	      (directory-files "/sys/class/power_supply/yeeloong-bat/" nil "charge_"))
	 'battery-yeeloong-sysfs)
	((and (eq system-type 'darwin)
	      (condition-case nil
		  (with-temp-buffer
		    (and (eq (call-process "pmset" nil t nil "-g" "ps") 0)
			 (> (buffer-size) 0)))
		(error nil)))
	 'battery-pmset)
	((eq system-type 'windows-nt)
	 'w32-battery-status))
  "Function for getting battery status information.
The function has to return an alist of conversion definitions.
Its cons cells are of the form

    (CONVERSION . REPLACEMENT-TEXT)

CONVERSION is the character code of a \"conversion specification\"
introduced by a `%' character in a control string."
  :type '(choice (const nil) function)
  :group 'battery)

(defcustom battery-echo-area-format
  (cond ((eq battery-status-function 'battery-linux-proc-acpi)
	 "Power %L, battery %B at %r (%p%% load, remaining time %t)")
	((eq battery-status-function 'battery-linux-sysfs)
	 "Power %L, battery %B (%p%% load)")
	((eq battery-status-function 'battery-pmset)
	 "%L power, battery %B (%p%% load, remaining time %t)")
	((eq battery-status-function 'battery-yeeloong-sysfs)
	 "%L power, battery %B (%p%% load, remaining time %t)")
	(battery-status-function
	 "Power %L, battery %B (%p%% load, remaining time %t)"))
  "Control string formatting the string to display in the echo area.
Ordinary characters in the control string are printed as-is, while
conversion specifications introduced by a `%' character in the control
string are substituted as defined by the current value of the variable
`battery-status-function'.  Here are the ones generally available:
%c Current capacity (mAh or mWh)
%r Current rate of charge or discharge
%B Battery status (verbose)
%b Battery status: empty means high, `-' means low,
   `!' means critical, and `+' means charging
%d Temperature (in degrees Celsius)
%L AC line status (verbose)
%p Battery load percentage
%m Remaining time (to charge or discharge) in minutes
%h Remaining time (to charge or discharge) in hours
%t Remaining time (to charge or discharge) in the form `h:min'"
  :type '(choice string (const nil))
  :group 'battery)

(defvar battery-mode-line-string nil
  "String to display in the mode line.")
;;;###autoload (put 'battery-mode-line-string 'risky-local-variable t)

(defcustom battery-mode-line-limit 100
  "Percentage of full battery load below which display battery status"
  :type 'integer
  :group 'battery)

(defcustom battery-mode-line-format
  (cond ((eq battery-status-function 'battery-linux-proc-acpi)
	 "[%b%p%%,%d°C]")
	(battery-status-function
	 "[%b%p%%]"))
  "Control string formatting the string to display in the mode line.
Ordinary characters in the control string are printed as-is, while
conversion specifications introduced by a `%' character in the control
string are substituted as defined by the current value of the variable
`battery-status-function'.  Here are the ones generally available:
%c Current capacity (mAh or mWh)
%r Current rate of charge or discharge
%B Battery status (verbose)
%b Battery status: empty means high, `-' means low,
   `!' means critical, and `+' means charging
%d Temperature (in degrees Celsius)
%L AC line status (verbose)
%p Battery load percentage
%m Remaining time (to charge or discharge) in minutes
%h Remaining time (to charge or discharge) in hours
%t Remaining time (to charge or discharge) in the form `h:min'"
  :type '(choice string (const nil))
  :group 'battery)

(defcustom battery-update-interval 60
  "Seconds after which the battery status will be updated."
  :type 'integer
  :group 'battery)

(defcustom battery-load-low 25
  "Upper bound of low battery load percentage.
A battery load percentage below this number is considered low."
  :type 'integer
  :group 'battery)

(defcustom battery-load-critical 10
  "Upper bound of critical battery load percentage.
A battery load percentage below this number is considered critical."
  :type 'integer
  :group 'battery)

(defvar battery-update-timer nil
  "Interval timer object.")

;;;###autoload
(defun battery ()
  "Display battery status information in the echo area.
The text being displayed in the echo area is controlled by the variables
`battery-echo-area-format' and `battery-status-function'."
  (interactive)
  (message "%s" (if (and battery-echo-area-format battery-status-function)
		    (battery-format battery-echo-area-format
				    (funcall battery-status-function))
		  "Battery status not available")))

;;;###autoload
(define-minor-mode display-battery-mode
  "Toggle battery status display in mode line (Display Battery mode).
With a prefix argument ARG, enable Display Battery mode if ARG is
positive, and disable it otherwise.  If called from Lisp, enable
the mode if ARG is omitted or nil.

The text displayed in the mode line is controlled by
`battery-mode-line-format' and `battery-status-function'.
The mode line is be updated every `battery-update-interval'
seconds."
  :global t :group 'battery
  (setq battery-mode-line-string "")
  (or global-mode-string (setq global-mode-string '("")))
  (and battery-update-timer (cancel-timer battery-update-timer))
  (if (and battery-status-function battery-mode-line-format)
      (if (not display-battery-mode)
	  (setq global-mode-string
		(delq 'battery-mode-line-string global-mode-string))
	(add-to-list 'global-mode-string 'battery-mode-line-string t)
	(setq battery-update-timer (run-at-time nil battery-update-interval
						'battery-update-handler))
	(battery-update))
    (message "Battery status not available")
    (setq display-battery-mode nil)))

(defun battery-update-handler ()
  (battery-update)
  (sit-for 0))

(defun battery-update ()
  "Update battery status information in the mode line."
  (let ((data (and battery-status-function (funcall battery-status-function))))
    (setq battery-mode-line-string
	  (propertize (if (and battery-mode-line-format
			       (<= (car (read-from-string (cdr (assq ?p data))))
				   battery-mode-line-limit))
			  (battery-format
			   battery-mode-line-format
			   data)
			"")
		      'face
		      (and (<= (car (read-from-string (cdr (assq ?p data))))
				   battery-load-critical)
			   'error)
		      'help-echo "Battery status information")))
  (force-mode-line-update))

;;; `/proc/apm' interface for Linux.

(defconst battery-linux-proc-apm-regexp
  (concat "^\\([^ ]+\\)"		; Driver version.
	  " \\([^ ]+\\)"		; APM BIOS version.
	  " 0x\\([0-9a-f]+\\)"		; APM BIOS flags.
	  " 0x\\([0-9a-f]+\\)"		; AC line status.
	  " 0x\\([0-9a-f]+\\)"		; Battery status.
	  " 0x\\([0-9a-f]+\\)"		; Battery flags.
	  " \\(-?[0-9]+\\)%"		; Load percentage.
	  " \\(-?[0-9]+\\)"		; Remaining time.
	  " \\(.*\\)"			; Time unit.
	  "$")
  "Regular expression matching contents of `/proc/apm'.")

(defun battery-linux-proc-apm ()
  "Get APM status information from Linux (the kernel).
This function works only with the new `/proc/apm' format introduced
in Linux version 1.3.58.

The following %-sequences are provided:
%v Linux driver version
%V APM BIOS version
%I APM BIOS status (verbose)
%L AC line status (verbose)
%B Battery status (verbose)
%b Battery status, empty means high, `-' means low,
   `!' means critical, and `+' means charging
%p Battery load percentage
%s Remaining time (to charge or discharge) in seconds
%m Remaining time (to charge or discharge) in minutes
%h Remaining time (to charge or discharge) in hours
%t Remaining time (to charge or discharge) in the form `h:min'"
  (let (driver-version bios-version bios-interface line-status
	battery-status battery-status-symbol load-percentage
	seconds minutes hours remaining-time tem)
    (with-temp-buffer
      (ignore-errors (insert-file-contents "/proc/apm"))
      (when (re-search-forward battery-linux-proc-apm-regexp)
	(setq driver-version (match-string 1))
	(setq bios-version (match-string 2))
	(setq tem (string-to-number (match-string 3) 16))
	(if (not (logand tem 2))
	    (setq bios-interface "not supported")
	  (setq bios-interface "enabled")
	  (cond ((logand tem 16) (setq bios-interface "disabled"))
		((logand tem 32) (setq bios-interface "disengaged")))
	  (setq tem (string-to-number (match-string 4) 16))
	  (cond ((= tem 0) (setq line-status "off-line"))
		((= tem 1) (setq line-status "on-line"))
		((= tem 2) (setq line-status "on backup")))
	  (setq tem (string-to-number (match-string 6) 16))
	  (if (= tem 255)
	      (setq battery-status "N/A")
	    (setq tem (string-to-number (match-string 5) 16))
	    (cond ((= tem 0) (setq battery-status "high"
				   battery-status-symbol ""))
		  ((= tem 1) (setq battery-status "low"
				   battery-status-symbol "-"))
		  ((= tem 2) (setq battery-status "critical"
				   battery-status-symbol "!"))
		  ((= tem 3) (setq battery-status "charging"
				   battery-status-symbol "+")))
	    (setq load-percentage (match-string 7))
	    (setq seconds (string-to-number (match-string 8)))
	    (and (string-equal (match-string 9) "min")
		 (setq seconds (* 60 seconds)))
	    (setq minutes (/ seconds 60)
		  hours (/ seconds 3600))
	    (setq remaining-time
		  (format "%d:%02d" hours (- minutes (* 60 hours))))))))
    (list (cons ?v (or driver-version "N/A"))
	  (cons ?V (or bios-version "N/A"))
	  (cons ?I (or bios-interface "N/A"))
	  (cons ?L (or line-status "N/A"))
	  (cons ?B (or battery-status "N/A"))
	  (cons ?b (or battery-status-symbol ""))
	  (cons ?p (or load-percentage "N/A"))
	  (cons ?s (or (and seconds (number-to-string seconds)) "N/A"))
	  (cons ?m (or (and minutes (number-to-string minutes)) "N/A"))
	  (cons ?h (or (and hours (number-to-string hours)) "N/A"))
	  (cons ?t (or remaining-time "N/A")))))


;;; `/proc/acpi/' interface for Linux.

(defun battery-linux-proc-acpi ()
  "Get ACPI status information from Linux (the kernel).
This function works only with the `/proc/acpi/' format introduced
in Linux version 2.4.20 and 2.6.0.

The following %-sequences are provided:
%c Current capacity (mAh)
%r Current rate
%B Battery status (verbose)
%b Battery status, empty means high, `-' means low,
   `!' means critical, and `+' means charging
%d Temperature (in degrees Celsius)
%L AC line status (verbose)
%p Battery load percentage
%m Remaining time (to charge or discharge) in minutes
%h Remaining time (to charge or discharge) in hours
%t Remaining time (to charge or discharge) in the form `h:min'"
  (let ((design-capacity 0)
	(last-full-capacity 0)
	full-capacity
	(warn 0)
	(low 0)
	capacity rate rate-type charging-state minutes hours)
    ;; ACPI provides information about each battery present in the system in
    ;; a separate subdirectory.  We are going to merge the available
    ;; information together since displaying for a variable amount of
    ;; batteries seems overkill for format-strings.
    (with-temp-buffer
      (dolist (dir (ignore-errors (directory-files "/proc/acpi/battery/"
						   t "\\`[^.]")))
	(erase-buffer)
	(ignore-errors (insert-file-contents (expand-file-name "state" dir)))
	(when (re-search-forward "present: +yes$" nil t)
	  (and (re-search-forward "charging state: +\\(.*\\)$" nil t)
	       (member charging-state '("unknown" "charged" nil))
	       ;; On most multi-battery systems, most of the time only one
	       ;; battery is "charging"/"discharging", the others are
	       ;; "unknown".
	       (setq charging-state (match-string 1)))
	  (when (re-search-forward "present rate: +\\([0-9]+\\) \\(m[AW]\\)$"
				   nil t)
	    (setq rate (+ (or rate 0) (string-to-number (match-string 1)))
		  rate-type (or (and rate-type
				     (if (string= rate-type (match-string 2))
					 rate-type
				       (error
					"Inconsistent rate types (%s vs. %s)"
					rate-type (match-string 2))))
				(match-string 2))))
	  (when (re-search-forward "remaining capacity: +\\([0-9]+\\) m[AW]h$"
				   nil t)
	    (setq capacity
		  (+ (or capacity 0) (string-to-number (match-string 1))))))
	(goto-char (point-max))
	(ignore-errors (insert-file-contents (expand-file-name "info" dir)))
	(when (re-search-forward "present: +yes$" nil t)
	  (when (re-search-forward "design capacity: +\\([0-9]+\\) m[AW]h$"
				   nil t)
	    (incf design-capacity (string-to-number (match-string 1))))
	  (when (re-search-forward "last full capacity: +\\([0-9]+\\) m[AW]h$"
				   nil t)
	    (incf last-full-capacity (string-to-number (match-string 1))))
	  (when (re-search-forward
		 "design capacity warning: +\\([0-9]+\\) m[AW]h$" nil t)
	    (incf warn (string-to-number (match-string 1))))
	  (when (re-search-forward "design capacity low: +\\([0-9]+\\) m[AW]h$"
				   nil t)
	    (incf low (string-to-number (match-string 1)))))))
    (setq full-capacity (if (> last-full-capacity 0)
			    last-full-capacity design-capacity))
    (and capacity rate
	 (setq minutes (if (zerop rate) 0
			 (floor (* (/ (float (if (string= charging-state
							  "charging")
						 (- full-capacity capacity)
					       capacity))
				      rate)
				   60)))
	       hours (/ minutes 60)))
    (list (cons ?c (or (and capacity (number-to-string capacity)) "N/A"))
	  (cons ?L (or (battery-search-for-one-match-in-files
			(mapcar (lambda (e) (concat e "/state"))
				(ignore-errors
				  (directory-files "/proc/acpi/ac_adapter/"
						   t "\\`[^.]")))
			"state: +\\(.*\\)$" 1)

		       "N/A"))
	  (cons ?d (or (battery-search-for-one-match-in-files
			(mapcar (lambda (e) (concat e "/temperature"))
				(ignore-errors
				  (directory-files "/proc/acpi/thermal_zone/"
						   t "\\`[^.]")))
			"temperature: +\\([0-9]+\\) C$" 1)

		       "N/A"))
	  (cons ?r (or (and rate (concat (number-to-string rate) " "
					 rate-type)) "N/A"))
	  (cons ?B (or charging-state "N/A"))
	  (cons ?b (or (and (string= charging-state "charging") "+")
		       (and capacity (< capacity low) "!")
		       (and capacity (< capacity warn) "-")
		       ""))
	  (cons ?h (or (and hours (number-to-string hours)) "N/A"))
	  (cons ?m (or (and minutes (number-to-string minutes)) "N/A"))
	  (cons ?t (or (and minutes
			    (format "%d:%02d" hours (- minutes (* 60 hours))))
		       "N/A"))
	  (cons ?p (or (and full-capacity capacity
			    (> full-capacity 0)
			    (number-to-string
			     (floor (/ capacity
				       (/ (float full-capacity) 100)))))
		       "N/A")))))


;;; `/sys/class/power_supply/BATN' interface for Linux.

(defun battery-linux-sysfs ()
  "Get ACPI status information from Linux kernel.
This function works only with the new `/sys/class/power_supply/'
format introduced in Linux version 2.4.25.

The following %-sequences are provided:
%c Current capacity (mAh or mWh)
%r Current rate
%B Battery status (verbose)
%d Temperature (in degrees Celsius)
%p Battery load percentage
%L AC line status (verbose)
%m Remaining time (to charge or discharge) in minutes
%h Remaining time (to charge or discharge) in hours
%t Remaining time (to charge or discharge) in the form `h:min'"
  (let (charging-state rate temperature hours
	(charge-full 0.0)
	(charge-now 0.0)
	(energy-full 0.0)
	(energy-now 0.0))
    ;; SysFS provides information about each battery present in the
    ;; system in a separate subdirectory.  We are going to merge the
    ;; available information together.
    (with-temp-buffer
      (dolist (dir (ignore-errors
		    (directory-files
		     "/sys/class/power_supply/" t "BAT[0-9]$")))
	(erase-buffer)
	(ignore-errors (insert-file-contents
			(expand-file-name "uevent" dir)))
	(when (re-search-forward "POWER_SUPPLY_PRESENT=1$" nil t)
	  (goto-char (point-min))
	  (and (re-search-forward "POWER_SUPPLY_STATUS=\\(.*\\)$" nil t)
	       (member charging-state '("Unknown" "Full" nil))
	       (setq charging-state (match-string 1)))
	  (when (re-search-forward
                 "POWER_SUPPLY_\\(CURRENT\\|POWER\\)_NOW=\\([0-9]*\\)$"
                 nil t)
	    (setq rate (float (string-to-number (match-string 2)))))
	  (when (re-search-forward "POWER_SUPPLY_TEMP=\\([0-9]*\\)$" nil t)
	    (setq temperature (match-string 1)))
	  (let (full-string now-string)
	    ;; Sysfs may list either charge (mAh) or energy (mWh).
	    ;; Keep track of both, and choose which to report later.
	    (cond ((and (re-search-forward
			 "POWER_SUPPLY_CHARGE_FULL=\\([0-9]*\\)$" nil t)
			(setq full-string (match-string 1))
			(re-search-forward
			 "POWER_SUPPLY_CHARGE_NOW=\\([0-9]*\\)$" nil t)
			(setq now-string (match-string 1)))
		   (setq charge-full (+ charge-full
					(string-to-number full-string))
			 charge-now  (+ charge-now
					(string-to-number now-string))))
		  ((and (re-search-forward
			 "POWER_SUPPLY_ENERGY_FULL=\\([0-9]*\\)$" nil t)
			(setq full-string (match-string 1))
			(re-search-forward
			 "POWER_SUPPLY_ENERGY_NOW=\\([0-9]*\\)$" nil t)
			(setq now-string (match-string 1)))
		   (setq energy-full (+ energy-full
					(string-to-number full-string))
			 energy-now  (+ energy-now
					(string-to-number now-string))))))
	  (goto-char (point-min))
	  (when (and energy-now rate (not (zerop rate))
		     (re-search-forward
                      "POWER_SUPPLY_VOLTAGE_NOW=\\([0-9]*\\)$" nil t))
	    (let ((remaining (if (string= charging-state "Discharging")
				 energy-now
			       (- energy-full energy-now))))
	      (setq hours (/ (/ (* remaining (string-to-number
                                              (match-string 1)))
                                rate)
			     10000000.0)))))))
    (list (cons ?c (cond ((or (> charge-full 0) (> charge-now 0))
			  (number-to-string charge-now))
			 ((or (> energy-full 0) (> energy-now 0))
			  (number-to-string energy-now))
			 (t "N/A")))
	  (cons ?r (if rate (format "%.1f" (/ rate 1000000.0)) "N/A"))
	  (cons ?m (if hours (format "%d" (* hours 60)) "N/A"))
	  (cons ?h (if hours (format "%d" hours) "N/A"))
	  (cons ?t (if hours
		       (format "%d:%02d" hours (* (- hours (floor hours)) 60))
		     "N/A"))
	  (cons ?d (or temperature "N/A"))
	  (cons ?B (or charging-state "N/A"))
	  (cons ?p (cond ((> charge-full 0)
			  (format "%.1f"
				  (/ (* 100 charge-now) charge-full)))
			 ((> energy-full 0)
			  (format "%.1f"
				  (/ (* 100 energy-now) energy-full)))
			 (t "N/A")))
	  (cons ?L (if (file-readable-p "/sys/class/power_supply/AC/online")
		       (if (battery-search-for-one-match-in-files
			    (list "/sys/class/power_supply/AC/online"
				  "/sys/class/power_supply/ACAD/online")
			    "1" 0)
			   "AC"
			 "BAT")
		     "N/A")))))

(defun battery-yeeloong-sysfs ()
  "Get ACPI status information from Linux (the kernel).
This function works only on the Lemote Yeeloong.

The following %-sequences are provided:
%c Current capacity (mAh)
%r Current rate
%B Battery status (verbose)
%b Battery status, empty means high, `-' means low,
   `!' means critical, and `+' means charging
%L AC line status (verbose)
%p Battery load percentage
%m Remaining time (to charge or discharge) in minutes
%h Remaining time (to charge or discharge) in hours
%t Remaining time (to charge or discharge) in the form `h:min'"

  (let (capacity
	capacity-level
	status
	ac-online
	hours
	current-now
	charge-full
	charge-now)

    (with-temp-buffer
      (ignore-errors
	(insert-file-contents "/sys/class/power_supply/yeeloong-bat/uevent")
	(goto-char 1)
	(search-forward "POWER_SUPPLY_CHARGE_NOW=")
	(setq charge-now (read (current-buffer)))
	(goto-char 1)
	(search-forward "POWER_SUPPLY_CHARGE_FULL=")
	(setq charge-full (read (current-buffer)))
	(goto-char 1)
	(search-forward "POWER_SUPPLY_CURRENT_NOW=")
	(setq current-now (read (current-buffer)))
	(goto-char 1)
	(search-forward "POWER_SUPPLY_CAPACITY_LEVEL=")
	(setq capacity-level (buffer-substring (point) (line-end-position)))
	(goto-char 1)
	(search-forward "POWER_SUPPLY_STATUS=")
	(setq status (buffer-substring (point) (line-end-position))))
	
      (erase-buffer)
      (ignore-errors
	(insert-file-contents
	 "/sys/class/power_supply/yeeloong-ac/online")
	(goto-char 1)
	(setq ac-online (read (current-buffer)))
	(erase-buffer)))


    (setq capacity (round (/ (* charge-now 100.0) charge-full)))
    (when (and current-now (not (= current-now 0)))
      (if (< current-now 0)
	  ;; Charging
	  (setq hours (/ (- charge-now charge-full) (+ 0.0 current-now)))
	;; Discharging
	(setq hours (/ charge-now (+ 0.0 current-now)))))

    (list (cons ?c (if charge-now
		       (number-to-string charge-now)
		     "N/A"))
	  (cons ?r current-now)
	  (cons ?B (cond ((equal capacity-level "Full") "full")
			 ((equal status "Charging") "charging")
			 ((equal capacity-level "Low") "low")
			 ((equal capacity-level "Critical") "critical")
			 (t "high")))
	  (cons ?b (cond ((equal capacity-level "Full") " ")
			 ((equal status "Charging") "+")
			 ((equal capacity-level "Low") "-")
			 ((equal capacity-level "Critical") "!")
			 (t " ")))
	  (cons ?h (if hours (number-to-string hours) "N/A"))
	  (cons ?m (if hours (number-to-string (* 60 hours)) "N/A"))
	  (cons ?t (if hours
		       (format "%d:%d"
			       (/ (round (* 60 hours)) 60)
			       (% (round (* 60 hours)) 60))
		     "N/A"))
	  (cons ?p (if capacity (number-to-string capacity) "N/A"))
	  (cons ?L (if (eq ac-online 1) "AC" "BAT")))))

;;; `pmset' interface for Darwin (OS X).

(defun battery-pmset ()
  "Get battery status information using `pmset'.

The following %-sequences are provided:
%L Power source (verbose)
%B Battery status (verbose)
%b Battery status, empty means high, `-' means low,
   `!' means critical, and `+' means charging
%p Battery load percentage
%h Remaining time in hours
%m Remaining time in minutes
%t Remaining time in the form `h:min'"
  (let (power-source load-percentage battery-status battery-status-symbol
	remaining-time hours minutes)
    (with-temp-buffer
      (ignore-errors (call-process "pmset" nil t nil "-g" "ps"))
      (goto-char (point-min))
      (when (re-search-forward "Currentl?y drawing from '\\(AC\\|Battery\\) Power'" nil t)
	(setq power-source (match-string 1))
	(when (re-search-forward "^ -InternalBattery-0[ \t]+" nil t)
	  (when (looking-at "\\([0-9]\\{1,3\\}\\)%")
	    (setq load-percentage (match-string 1))
	    (goto-char (match-end 0))
	    (cond ((looking-at "; charging")
		   (setq battery-status "charging"
			 battery-status-symbol "+"))
		  ((< (string-to-number load-percentage) battery-load-low)
		   (setq battery-status "low"
			 battery-status-symbol "-"))
		  ((< (string-to-number load-percentage) battery-load-critical)
		   (setq battery-status "critical"
			 battery-status-symbol "!"))
		  (t
		   (setq battery-status "high"
			 battery-status-symbol "")))
	    (when (re-search-forward "\\(\\([0-9]+\\):\\([0-9]+\\)\\) remaining"  nil t)
	      (setq remaining-time (match-string 1))
	      (let ((h (string-to-number (match-string 2)))
		    (m (string-to-number (match-string 3))))
		(setq hours (number-to-string (+ h (if (< m 30) 0 1)))
		      minutes (number-to-string (+ (* h 60) m)))))))))
    (list (cons ?L (or power-source "N/A"))
	  (cons ?p (or load-percentage "N/A"))
	  (cons ?B (or battery-status "N/A"))
	  (cons ?b (or battery-status-symbol ""))
	  (cons ?h (or hours "N/A"))
	  (cons ?m (or minutes "N/A"))
	  (cons ?t (or remaining-time "N/A")))))


;;; Private functions.

(defun battery-format (format alist)
  "Substitute %-sequences in FORMAT."
  (replace-regexp-in-string
   "%."
   (lambda (str)
     (let ((char (aref str 1)))
       (if (eq char ?%) "%"
	 (or (cdr (assoc char alist)) ""))))
   format t t))

(defun battery-search-for-one-match-in-files (files regexp match-num)
  "Search REGEXP in the content of the files listed in FILES.
If a match occurred, return the parenthesized expression numbered by
MATCH-NUM in the match.  Otherwise, return nil."
  (with-temp-buffer
    (catch 'found
      (dolist (file files)
	(and (ignore-errors (insert-file-contents file nil nil nil 'replace))
	     (re-search-forward regexp nil t)
	     (throw 'found (match-string match-num)))))))


(provide 'battery)

;;; battery.el ends here