#include <stdio.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/wait.h>
#include <sys/times.h>

int main(int argc, char **argv) {

	if (argc < 2) {
		puts("time: missing operand\ntime [cmd]");
		return 0;
	}

	long ticks = sysconf(_SC_CLK_TCK);
	if (ticks <= 0) {
		fprintf(stderr, "time: %s\n", strerror(errno));
		return 1;
	}

	static struct tms tms;
	clock_t r1 = times(&tms);
	if (r1 == (clock_t)-1) {
		fprintf(stderr, "time: %s\n", strerror(errno));
		return 1;
	}

	/* Run */
	pid_t pid;
	if ((pid = fork()) == 0) {
		execvp(argv[1], argv + 1);
		exit(1);
	}

	int status = 0;
	waitpid(pid, &status, 0);

	/* Get time */
	clock_t r2 = times(&tms);
	if (r2 == (clock_t)-1) {
		fprintf(stderr, "time: %s\n", strerror(errno));
		return 1;
	}

	/* Print */
	long real = (r2 - r1) / ticks;
	long user = tms.tms_cutime / ticks;
	long sys = tms.tms_cstime / ticks;

	fprintf(stderr, "real:\t%ldm %ld.%lds\nsys:\t%ldm %ld.%lds\nuser:\t%ldm %ld.%lds\n", real / 60, real % 60, (r2 - r1) % 100, sys / 60, sys % 60, tms.tms_cstime % 100, user / 60, user % 60, tms.tms_cutime % 100);
	if (status != 0)
		printf("Proccess returned %d\n", status);

	return 0;
}