summaryrefslogtreecommitdiff
path: root/bat0.c
blob: 316a29a628f11523ce0898fa46eb1a5353056ea8 (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
#include <signal.h>
#include <signal.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <string.h>
#include <stdio.h>
#include <sys/stat.h>

volatile int need_exit = 0;

static __off_t getfile_size(int fd)
{
        struct stat st;
        int ret;

        ret = fstat(fd, &st);
        if (ret == -1) {
                perror("fstat");
                return -1;
        }

        return st.st_size;
}

static int open_bat0(const char* bat0dir)
{
        return open(bat0dir, O_RDONLY);
}

static char* read_bat0(int fd)
{
        off_t size = getfile_size(fd);
        char *buf = (char*)malloc(size);
        memset(buf, '\0', size);
        read(fd, buf, size);
        return buf;
}

static int close_bat0(int fd)
{
        return close(fd);
}

void signal_cb(int signal)
{
        need_exit = 1;
}

int main()
{
        signal(SIGINT, signal_cb);

        while (!need_exit) {
                int fd = open_bat0("/sys/class/power_supply/BAT0/capacity");
                char* bat0data = read_bat0(fd);

                printf("%s\n", bat0data);
                free(bat0data);

                close_bat0(fd);
                sleep(3);
        }
}