原文链接： http://www.cnblogs.com/nwf5d/archive/2011/06/03/2071247.html

#ifdef HAVE_CONFIG_H

#include <config.h>
#endif

#include <stdio.h>
#include <stdlib.h>
#include <sys/time.h>
int main(int argc, char *argv[])
{
printf("Hello, world!\n");
struct timeval tvafter,tvpre;
struct timezone tz;
int sum = 0; 
int i=0;
gettimeofday (&tvpre , &tz);

for(i = 0; i < 100000000; i++)
{
sum += i;
} 
gettimeofday (&tvafter , &tz);
printf("sum=%d 花费时间:%d\n",sum, (tvafter.tv_sec-tvpre.tv_sec)*1000+(tvafter.tv_usec-tvpre.tv_usec)/1000);
return EXIT_SUCCESS;