Linux5 get time functions

# Include <sys/time. h> <br/> # include <time. h> <br/> # include <stdio. h> <br/> # include <iostream> <br/> # include <string. h> <br/> using namespace std; <br/> double difftimeval (const struct timeval * tv1, const struct timeval * tv2) <br/>{< br/> double d; <br/> time_t s; <br/> suseconds_t u; <br/> s = tv1-> TV _sec-tv2-> TV _sec; <br/> u = tv1-> TV _usec-tv2-> TV _usec; <br/> if (u <0) <br/> -- s; <br/> d = s. <br/> d * = 1000000.0; <br/> d + = u; <br/> return d; <br/>}< br/> char * strftimeval (const struct timeval * TV, char * buf) <br/>{< br/> struct tm; <br/> size_t len = 28; <br/> localtime_r (& TV-> TV _sec, & tm ); <br/> strftime (buf, len, "% Y-% m-% d % H: % M: % S", & tm ); <br/> len = strlen (buf); <br/> sprintf (buf + len ,". % 06.6d ", (int) (TV-> TV _usec); <br/> return buf; <br/>}< br/> char * getstimeval (char * buf) <br/>{< br/> struct timeval TV; <br/> struct tm; <br/> size_t len = 28; <br/> gettimeofday (& TV, NULL); <br/> localtime_r (& TV. TV _sec, & tm); <br/> strftime (buf, len, "% Y-% m-% d % H: % M: % S", & tm ); <br/> len = strlen (buf); <br/> sprintf (buf + len ,". % 06.6d ", (int) (TV. TV _usec); <br/> return buf; <br/>}< br/> // get system time <br/> void SendCentreTime (char * sCurDate) <br/>{< br/> struct tm * current_date; <br/> time_t seconds; <br/> time (& seconds ); <br/> current_date = localtime (& seconds); <br/> memset (sCurDate, 0, sizeof (sCurDate); <br/> sprintf (sCurDate, "% 04d % 02d % 02d % 02d % 02d % 02d", <br/> current_date-> tm_year + 1900, <br/> current_date-> tm_mon + 1, <br/> current_date-> tm_mday, <br/> current_date-> tm_hour, <br/> current_date-> tm_min, <br/> current_date-> tm_sec ); <br/>}< br/> long GetMillSec () <br/>{< br/> long nMillSec = 0; </p> <p> struct timeval TV; <br/> gettimeofday (& TV, NULL); </p> <p> nMillSec = (long) TV. TV _sec * 1000; <br/> nMillSec + = TV. TV _usec/1000; </p> <p> return nMillSec; <br/>}< br/> int main (int argc, char * argv []) <br/>{< br/> char buf [28]; <br/> char cDate [128] = {0}; <br/> struct timeval tv1; <br/> struct timeval tv2; </p> <p> long tm = GetMillSec (); <br/> SendCentreTime (cDate ); <br/> gettimeofday (& tv1, NULL); <br/> printf ("% s/n", getstimeval (buf); <br/> gettimeofday (& tv2, NULL); <br/> printf ("% s/n", strftimeval (& tv1, buf); <br/> printf ("% s/n ", strftimeval (& tv2, buf); <br/> printf ("% f/n", difftimeval (& tv2, & tv1); <br/> return 0; <br/>}< br/>