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
|
/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
/***
This file is part of systemd.
Copyright 2010 Lennart Poettering
systemd is free software; you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
systemd 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
#include <stdlib.h>
#include <stdbool.h>
#include <errno.h>
#include <string.h>
#include <libudev.h>
#include "util.h"
static int on_ac_power(void) {
int r;
struct udev *udev;
struct udev_enumerate *e = NULL;
struct udev_list_entry *item = NULL, *first = NULL;
bool found_offline = false, found_online = false;
if (!(udev = udev_new())) {
r = -ENOMEM;
goto finish;
}
if (!(e = udev_enumerate_new(udev))) {
r = -ENOMEM;
goto finish;
}
if (udev_enumerate_add_match_subsystem(e, "power_supply") < 0) {
r = -EIO;
goto finish;
}
if (udev_enumerate_scan_devices(e) < 0) {
r = -EIO;
goto finish;
}
first = udev_enumerate_get_list_entry(e);
udev_list_entry_foreach(item, first) {
struct udev_device *d;
const char *type, *online;
if (!(d = udev_device_new_from_syspath(udev, udev_list_entry_get_name(item)))) {
r = -ENOMEM;
goto finish;
}
if (!(type = udev_device_get_sysattr_value(d, "type")))
goto next;
if (!streq(type, "Mains"))
goto next;
if (!(online = udev_device_get_sysattr_value(d, "online")))
goto next;
if (streq(online, "1")) {
found_online = true;
break;
} else if (streq(online, "0"))
found_offline = true;
next:
udev_device_unref(d);
}
r = found_online || !found_offline;
finish:
if (e)
udev_enumerate_unref(e);
if (udev)
udev_unref(udev);
return r;
}
int main(int argc, char *argv[]) {
int r;
/* This is mostly intended to be used for scripts which want
* to detect whether AC power is plugged in or not. */
if ((r = on_ac_power()) < 0) {
log_error("Failed to read AC status: %s", strerror(-r));
return EXIT_FAILURE;
}
return r == 0;
}
|
