From 7d8e3fd4a2f7505703de7950f36dd0548b620b5e Mon Sep 17 00:00:00 2001
From: dm1sh <me@dmitriy.icu>
Date: Mon, 27 Jun 2022 23:40:10 +0300
Subject: [PATCH] initial commit

---
 main.c | 107 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 107 insertions(+)
 create mode 100644 main.c

diff --git a/main.c b/main.c
new file mode 100644
index 0000000..5e28362
--- /dev/null
+++ b/main.c
@@ -0,0 +1,107 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <string.h>
+
+#define ACPI_DEVICE "amdgpu_bl0"
+#define BACKLIGHT_PATH "/sys/class/backlight/"
+#define NAME_BUFF_SIZE (sizeof(BACKLIGHT_PATH) + 20 + 15)
+
+FILE *open_file(char *path, char *mode) {
+	FILE *fp = fopen(path, mode);
+
+	if (!fp) {
+		fprintf(stderr, "Can't open file %s\n", path);
+		exit(EXIT_FAILURE);	
+	}
+
+	return fp;
+}
+
+int read_file(char *path) {
+	FILE *fp = open_file(path, "r");
+
+	static char buff[5];
+	fgets(buff, 5, fp);
+
+	fclose(fp);
+
+	return atoi(buff);
+}
+
+int main (int argc, char const *const *const argv) {
+	if (argc >= 1 && (strncmp(argv[argc - 1], "-h", 2) == 0 || strncmp(argv[argc - 1], "--help", 6) == 0)) {
+		printf("scrbrmg: a simple cli tool for screen brightness management.\n\n"
+				"Usage: scrbrmng \t\t\tShow current brightness percentage\n"
+				"   or: scrbrmng <number>\t\tSet current brightness with provided percentage\n"
+				"   or: scrbrmng +<number>, -<number>\tIncrease or decreace brightness percentage by provided number\n"
+				"   or: scrbrmng -h, --help\t\tShow this message\n");
+		exit(EXIT_SUCCESS);
+	}
+
+	char *max_brightness_path;
+	
+	bool custom_device = (argc == 2 && argv[1][0] != '-' && argv[1][0] != '+' && (argv[1][0] > '9' || argv[1][0] < '0')) || (argc > 2);
+	if (custom_device) {
+		max_brightness_path = malloc(NAME_BUFF_SIZE);
+		strcpy(max_brightness_path, BACKLIGHT_PATH);
+		strncat(max_brightness_path, argv[1], 20);
+		strcat(max_brightness_path, "/max_brightness");
+	} else {
+#ifdef ACPI_DEVICE
+		max_brightness_path = BACKLIGHT_PATH ACPI_DEVICE "/max_brightness";
+#else
+		fprintf(stderr, "scrbrmg was compiled without default ACPI_DEVICE. You must specify it as the first argument\n");
+		exit(EXIT_FAILURE);
+#endif
+	}
+
+	float max_brightness = read_file(max_brightness_path);
+
+	char* brightness_path;
+
+	if (custom_device) {
+		brightness_path = max_brightness_path;
+		memcpy(brightness_path + sizeof(BACKLIGHT_PATH) + strlen(argv[1]), "brightness", 11);
+	} else {
+#ifdef ACPI_DEVICE
+		brightness_path = BACKLIGHT_PATH ACPI_DEVICE "/brightness";
+#endif
+	}
+
+	bool get_brightness = argc == 1 || (custom_device && argc == 2); 
+	
+	int brightness = read_file(brightness_path);
+		
+	if (get_brightness) {
+		printf("%d\n", (int)((brightness / max_brightness) * 100 + 0.5));
+		exit(EXIT_SUCCESS);
+	}
+	
+	char const *const delta_s = argv[1 + custom_device];
+	
+	bool signd = delta_s[0] == '-' || delta_s[0] == '+';
+
+	int delta = atoi(delta_s + signd);
+
+	int res;
+
+	float percent = max_brightness / 100;
+
+	if (signd) {
+		if (delta_s[0] == '-') {
+			delta *= -1;
+		}
+
+		res = brightness + delta * percent + 0.5;
+	} else {
+		res = delta * percent + 0.5;
+	}
+
+	FILE *brightness_fp = open_file(brightness_path, "w");
+
+	fprintf(brightness_fp, "%d", res);
+
+	exit(EXIT_SUCCESS);
+}
+