#include <stdio.h>
#include <dirent.h>
#define INVALID -128

int read_int(char* filename) {
	printf("Reading filename %s\n", filename);
	int output = INVALID;
	FILE* pInput = fopen(filename, "r");
	if (pInput != NULL) {
		fscanf(pInput, "%d", &output);
		fclose(pInput);
	} else printf("No such file\n");
	return output;
}

int main() {
	FILE* pOutput;
	FILE* pInput;
	char filename[] = "/sys/class/drm/card?/device/gpu_busy_percent";  // ? is filename[19], overwrite each loop
	char hwmon_dirname[] = "/sys/class/drm/card?/device/hwmon";  // ? is hwmon_dirname[19], overwrite each loop
	for (int i = 0; i < 8; i++) {
		int usage = 0;
		int temperature = 0;
		char sOutput[16];
		filename[19] = i + 48;
		hwmon_dirname[19] = i + 48;

		usage = read_int(filename);
		if (usage == INVALID) break;

		DIR* folder = opendir(hwmon_dirname);
		if (folder == NULL) break;
		closedir(folder);

		char filename2[] = "/sys/class/drm/card0/device/hwmon/hwmon*/temp1_input";
		filename2[19] = i + 48;
		temperature = read_int(filename2);
		if (temperature == INVALID) break;

		// sprintf(sOutput, "%3d% %3d℃", usage, temperature);
		printf("%3d% %3d℃", usage, temperature);
	}
	return 0;
}