#include <stdio.h>
#include <stddef.h>
#include <sys/time.h>

#include "error.h"

double timestamp(void) {
	struct timeval  tv;

	if (gettimeofday(&tv, NULL) == -1) {
		return -1;
	}

	return tv.tv_sec + (tv.tv_usec * 1e-6);
}

unsigned long get_boot_time(void) {
	FILE *fp = fopen("/proc/stat", "r");
	if (!fp) {
		error("fopen /proc/stat: %s", strerror(errno));
		return 0;
	}

	char           buf[256];
	unsigned long  btime = 0;

	while (fgets(buf, sizeof(buf), fp)) {
		if (sscanf(buf, "btime %lu", &btime) == 1) {
			break;
		}
	}

	fclose(fp);
	return btime;
}