#include <iostream>
#include <ctime>
#include <sys/time.h>


static void print_usage(const char *argv0) {
	std::cerr
		<< "Usage: " << argv0 << " [OPTIONS]\n"
		<< "  -h    Show this help\n"
		<< "  -d    Print deltas in seconds, not timestamps\n"
		<< "  -s    Print tags in timestamp format\n"
		<< "  -t    Print tags in local time format (default)\n"
		<< std::flush;
}

enum Mode {
	M_STAMP,
	M_LOCALTIME,
	M_DELTA,
};

int main(int argc, char **argv) {
	// use std::cin, stdout, std::cerr
	std::ios::sync_with_stdio(false);

	Mode mode = M_LOCALTIME;
	for (int i = 1; i < argc; i++) {
		if (argv[i][0] != '-') {
			std::cerr << "Unrecognised argument: '" << argv[i] << "'" << std::endl;
			print_usage(argv[0]);
			return 1;
		}
		for (int j = 1; argv[i][j]; j++) {
			switch (argv[i][j]) {
				case 'h': print_usage(argv[0]); return 0;
				case 'd': mode = M_DELTA; break;
				case 's': mode = M_STAMP; break;
				case 't': mode = M_LOCALTIME; break;
				default: print_usage(argv[0]); return 1;
			}
		}
	}

	struct timeval tv;

	double prevtm;
	if (mode == M_DELTA) {
		gettimeofday(&tv, nullptr);
		prevtm = tv.tv_sec + tv.tv_usec * 1.0e-6;
	}

	std::string line;
	while (std::getline(std::cin, line)) {
		gettimeofday(&tv, nullptr);

		switch (mode) {
			case M_STAMP:
				printf("%.6lf %s\n", tv.tv_sec + tv.tv_usec * 1.0e-6, line.data());
				break;
			case M_LOCALTIME: {
				const struct tm *tm = localtime(&tv.tv_sec);
				char buffer[128];
				ssize_t nw = strftime(buffer, sizeof buffer - 7, "%Y-%m-%d %H:%M:%S.", tm);
				for (int i = 5; i >= 0; i--) {
					buffer[nw + i] = '0' + tv.tv_usec % 10;
					tv.tv_usec /= 10;
				}
				buffer[nw + 6] = '\0';
				printf("%s %s\n", buffer, line.data());
				break;
			}
			case M_DELTA: {
				double tm = tv.tv_sec + tv.tv_usec * 1.0e-6;
				printf("%.6lf %s\n", tm - prevtm, line.data());
				prevtm = tm;
				break;
			}
		}
	}
}