benchmark gcc and clang

bench.c

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

double run(char *arg[])
{
	pid_t pid = fork();
	if(pid == 0) {
		execvp(arg[0], arg);
	}
	wait(NULL);
	struct tms t;
	times(&t);
	return (double)(t.tms_cutime + t.tms_cstime)/sysconf(_SC_CLK_TCK);
}

int main(int argc, char *argv[])
{
	if(argc != 2) {
		fprintf(stderr, "usage: %s filename", argv[0]);
		return 1;
	}
	char *gcc[] = {"gcc", argv[1], "-o", "./test.gcc", (char*)NULL};
	char *clang[] = {"clang", argv[1],"-o", "./test.clang", (char*)NULL};
	printf(
	"prog  sec\n"
	"---------\n"
	"gcc   %lf\n"
	"clang %lf \n", run(gcc), run(clang));

	//remove("./test.gcc");
	//remove("./test.clang");
	return 0;
}