Microtime()等效于C和C++？

Question

我想知道是否有相当于C 和 C++中的PHP函数microtime().我环顾四周但找不到明确的答案.

谢谢!

Answer 1

没有完全等同于PHP的microtime(),但您可以使用基于以下代码的类似功能的函数:

Mac OS X,也可能是Linux/Unix

#include <sys/time.h>
struct timeval time;
gettimeofday(&time, NULL); #This actually returns a struct that has microsecond precision.
long microsec = ((unsigned long long)time.tv_sec * 1000000) + time.tv_usec;

(基于:http://brian.pontarelli.com/2009/01/05/getting-the-current-system-time-in-milliseconds-with-c/)

视窗:

unsigned __int64 freq;
QueryPerformanceFrequency((LARGE_INTEGER*)&freq);
double timerFrequency = (1.0/freq);

unsigned __int64 startTime;
QueryPerformanceCounter((LARGE_INTEGER *)&startTime);

//do something...

unsigned __int64 endTime;
QueryPerformanceCounter((LARGE_INTEGER *)&endTime);
double timeDifferenceInMilliseconds = ((endTime-startTime) * timerFrequency);

(由Darcara回答,来自:https://stackoverflow.com/a/4568649/330067 )

Answer 2

在Linux上,您可以使用gettimeofday,它应该提供相同的信息.事实上,我相信这是PHP使用的功能.