slstatus/components/backlight.c
David Demelier 37724ac2c3 Add basic backlight percentage support
At the moment linux only, but will add support for OpenBSD as well.
2018-05-22 12:40:31 +02:00

32 lines
679 B
C

/* See LICENSE file for copyright and license details. */
#include "../util.h"
#if defined(__linux__)
#include <limits.h>
#define BRIGHTNESS_MAX "/sys/class/backlight/%s/max_brightness"
#define BRIGHTNESS_CUR "/sys/class/backlight/%s/brightness"
const char *
backlight_perc(const char *card)
{
char path[PATH_MAX];
int max, cur;
if (esnprintf(path, sizeof (path), BRIGHTNESS_MAX, card) < 0 ||
pscanf(path, "%d", &max) != 1) {
return NULL;
}
if (esnprintf(path, sizeof (path), BRIGHTNESS_CUR, card) < 0 ||
pscanf(path, "%d", &cur) != 1) {
return NULL;
}
if (max == 0) {
return NULL;
}
return bprintf("%d", cur * 100 / max);
}
#endif