#include <sys/time.h>
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <libgen.h>

int main(int argc, char *argv[])
{
	unsigned long tsleep;
	struct timeval tv;

	if (argc != 2) {
		printf("usage: %s sleeptime\n", basename(argv[0]));
		return 1;
	}

	tsleep = atoi(argv[1]);
	if (tsleep == 0) {
		printf("usage: invalid sleeptime\n");
		return 2;
	}

	while(1) {
		if (gettimeofday(&tv, NULL) != 0)
			printf("gettimeofday failed\n");
		else
			printf("%ld.%ld\n", tv.tv_sec, tv.tv_usec);

		usleep(tsleep);
	}

	return 0;
}