在C ++中测量对system（）的调用的执行时间 [英] Measuring execution time of a call to system() in C++

问题描述

我在这里找到了一些测量执行时间的代码
http： //www.dreamincode.net/forums/index.php?showtopic=24685

但是，它似乎不适用于对system（）的调用， 。我想这是因为执行跳出当前进程。

  clock_t begin = clock（）; 
 
 system（something）; 
 
 clock_t end = clock（）; 
 cout<<执行时间：<<< diffclock（end，begin）<<s。<< endl; 
  

然后

  double diffclock（clock_t clock1，clock_t clock2）
 {
 double diffticks = clock1-clock2; 
 double diffms =（diffticks）/（CLOCKS_PER_SEC）; 
 return diffms; 
} 
  

但这总是返回0秒...还有另一种方法？

此外，只是为了添加，执行时间是以小时为单位。所以准确性不是真正的问题。

谢谢！

解决方案

http://dell5.ma.utexas.edu/cgi-bin/man-cgi?gettimeofday+2\"> gettimeofday ？

  struct timeval tv; 
 struct timeval start_tv; 
 
 gettimeofday（& start_tv，NULL）; 
 
 system（something）; 
 
 double elapsed = 0.0; 
 
 gettimeofday（& tv，NULL）; 
 elapsed =（tv.tv_sec  -  start_tv.tv_sec）+ 
（tv.tv_usec  -  start_tv.tv_usec）/ 1000000.0; 
  

I have found some code on measuring execution time here http://www.dreamincode.net/forums/index.php?showtopic=24685

However, it does not seem to work for calls to system(). I imagine this is because the execution jumps out of the current process.

clock_t begin=clock();

system(something);

clock_t end=clock();
cout<<"Execution time: "<<diffclock(end,begin)<<" s."<<endl;

Then

double diffclock(clock_t clock1,clock_t clock2)
{
    double diffticks=clock1-clock2;
    double diffms=(diffticks)/(CLOCKS_PER_SEC);
    return diffms;
}

However this always returns 0 seconds... Is there another method that will work?

Also, this is in Linux.

Edit: Also, just to add, the execution time is in the order of hours. So accuracy is not really an issue.

Thanks!

解决方案

Have you considered using gettimeofday?

struct timeval tv;
struct timeval start_tv;

gettimeofday(&start_tv, NULL);

system(something);

double elapsed = 0.0;

gettimeofday(&tv, NULL);
elapsed = (tv.tv_sec - start_tv.tv_sec) +
  (tv.tv_usec - start_tv.tv_usec) / 1000000.0;

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