At the moment linux only, but will add support for FreeBSD and OpenBSD
as well.
---
Makefile | 1 +
components/backlight.c | 33 +++++++++++++++++++++++++++++++++
slstatus.h | 3 +++
3 files changed, 37 insertions(+)
create mode 100644 components/backlight.c
diff --git a/Makefile b/Makefile
index 0e925cc..8e18969 100644
--- a/Makefile
+++ b/Makefile
@@ -6,6 +6,7 @@ include config.mk
REQ = util
COM =\
+ components/backlight\
components/battery\
components/cpu\
components/datetime\
diff --git a/components/backlight.c b/components/backlight.c
new file mode 100644
index 0000000..05c12aa
--- /dev/null
+++ b/components/backlight.c
@@ -0,0 +1,33 @@
+/* See LICENSE file for copyright and license details. */
+
+#include <stddef.h>
+
+#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) < 0) {
+ return NULL;
+ }
+
+ if (esnprintf(path, sizeof (path), BRIGHTNESS_CUR, card) < 0 ||
+ pscanf(path, "%d", &cur) < 0) {
+ return NULL;
+ }
+
+ return bprintf("%d%%", cur * 100 / max);
+}
+
+#endif
diff --git a/slstatus.h b/slstatus.h
index 8bd8bb5..a18b881 100644
--- a/slstatus.h
+++ b/slstatus.h
@@ -1,5 +1,8 @@
/* See LICENSE file for copyright and license details. */
+/* backlight */
+const char *backlight_perc(const char *);
+
/* battery */
const char *battery_perc(const char *);
const char *battery_state(const char *);
--
2.17.0
