From 37724ac2c3f496f4736223d0d8e5d8fecb933590 Mon Sep 17 00:00:00 2001 From: David Demelier Date: Tue, 22 May 2018 09:23:29 +0200 Subject: Add basic backlight percentage support At the moment linux only, but will add support for OpenBSD as well. --- components/backlight.c | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) create mode 100644 components/backlight.c (limited to 'components') diff --git a/components/backlight.c b/components/backlight.c new file mode 100644 index 0000000..f9c4096 --- /dev/null +++ b/components/backlight.c @@ -0,0 +1,32 @@ +/* See LICENSE file for copyright and license details. */ +#include "../util.h" + +#if defined(__linux__) + #include + + #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 -- cgit v1.2.3