Linux下用C获取当前时间

void getNowTime()
{
 timespec time;
 clock_gettime(CLOCK_REALTIME, &time); //获取相对于1970到现在的秒数
 tm nowTime;
 localtime_r(&time.tv_sec, &nowtime);
 char current[1024];
 sprintf(current, "%04d%02d%02d%02d:%02d:%02d", nowTime.tm_year + 1900, nowTime.tm_mon, nowTime.tm_mday, 
  nowTime.tm_hour, nowTime.tm_min, nowTime.tm_sec);
}

#include<time.h>

int clock_gettime(clockid_t clk_id,struct timespec *tp);

struct timespec

{

time_t tv_sec; /* 秒*/

long tv_nsec; /* 纳秒*/

};

#include <stdio.h>
#include <stddef.h>
#include <time.h>
int main(void)
{
 time_t timer;//time_t就是long int 类型
 struct tm *tblock;
 timer = time(NULL);
 tblock = localtime(&timer);
 printf("Local time is: %s\n", asctime(tblock));
 return 0;
}

#include<time.h>
#include<stdio.h>
int main()
{
 struct tm *t;
 time_t tt;
 time(&tt);
 t = localtime(&tt);
 printf("%4d年%02d月%02d日 %02d:%02d:%02d\n", t->tm_year + 1900, t->tm_mon + 1, t->tm_mday, t->tm_hour, t->tm_min, t->tm_sec);
 return 0;
}

#include <cstdlib> 
#include <iostream> 
#include <time.h> 
#include <stdio.h> 
 
using namespace std; 
 
int main(int argc, char *argv[]) 
{ 
 time_t tNow =time(NULL); 
 time_t tEnd = tNow + 1800; 
 //注意下面两行的区别 
 struct tm* ptm = localtime(&tNow); 
 struct tm* ptmEnd = localtime(&tEnd); 
 
 char szTmp[50] = {0}; 
 strftime(szTmp,50,"%H:%M:%S",ptm); 
 char szEnd[50] = {0}; 
 strftime(szEnd,50,"%H:%M:%S",ptmEnd); 
  
 
 printf("%s /n",szTmp); 
 printf("%s /n",szEnd); 
  
 
 system("PAUSE"); 
 return EXIT_SUCCESS; 
}

#include <cstdlib> 
#include <iostream> 
#include <time.h> 
#include <stdio.h> 
 
using namespace std; 
 
int main(int argc, char *argv[]) 
{ 
 time_t tNow =time(NULL); 
 time_t tEnd = tNow + 1800; 
 
 //在这里修改程序 
 //struct tm* ptm = localtime(&tNow); 
 //struct tm* ptmEnd = localtime(&tEnd); 
 struct tm ptm = { 0 }; 
 struct tm ptmEnd = { 0 }; 
 localtime_r(&tNow, &ptm); 
 localtime_r(&tEnd, &ptmEnd); 
  
 char szTmp[50] = {0}; 
 strftime(szTmp,50,"%H:%M:%S",&ptm); 
 char szEnd[50] = {0}; 
 strftime(szEnd,50,"%H:%M:%S",&ptmEnd); 
 printf("%s /n",szTmp); 
 printf("%s /n",szEnd); 
  
 
 system("PAUSE"); 
 return EXIT_SUCCESS; 
}

 struct tm {
     int tm_sec;  /* 秒 – 取值区间为[0,59] */ 
     int tm_min;  /* 分 - 取值区间为[0,59] */ 
     int tm_hour;  /* 时 - 取值区间为[0,23] */ 
     int tm_mday;  /* 一个月中的日期 - 取值区间为[1,31] */ 
     int tm_mon;  /* 月份（从一月开始，0代表一月） - 取值区间为[0,11] */ 
     int tm_year;  /* 年份，其值等于实际年份减去1900 */ 
     int tm_wday; /* 星期 – 取值区间为[0,6]，其中0代表星期天，1代表星期一 */ 
     int tm_yday; /* 从每年1月1日开始的天数– 取值区间[0,365]，其中0代表1月1日 */ 
     int tm_isdst; /* 夏令时标识符，夏令时tm_isdst为正；不实行夏令时tm_isdst为0 */ 
   };

 time_t now;
 time(&now);// 等同于now = time(NULL)
 printf("now time is %d\n", now);