linux下用time(NULL)函数和localtime()获取当前时间的方法

  /* time - 获取计算机系统当前的日历时间(Calender Time)   *     处理日期时间的函数都是以本函数的返回值为基础进行运算   *   * 函数原型：   *   #include <time.h>   *    *   time_t time(time_t *calptr);   *   * 返回值：   *   成功：秒数，从1970-1-1,00:00:00   *   * 使用：   *   time_t now;   *    *   time(&now); // == now = time(NULL);   */

  /*   * localtime - 将时间数值变换成本地时间,考虑到本地时区和夏令时标志   *   * 函数声明:   *   #include <time.h>   *   *   struct tm * localtime(const time_t *timer);   *   */

  //结构tm的定义为：    struct tm    {      int tm_sec; /* Seconds: 0-59 (K&R says 0-61?) */      int tm_min; /* Minutes: 0-59 */      int tm_hour; /* Hours since midnight: 0-23 */      int tm_mday; /* Day of the month: 1-31 */      int tm_mon; /* Months *since* january: 0-11 */      int tm_year; /* Years since 1900 */      int tm_wday; /* Days since Sunday (0-6) */      int tm_yday; /* Days since Jan. 1: 0-365 */      int tm_isdst; /* +1 Daylight Savings Time, 0 No DST,       * -1 don't know */    }; 

  /*  * time();  * @author 李政 <1244109467@qq.com>  */    #include <time.h>   #include <stdio.h>     int main(int argc, char* argv[])  {     struct tm *tp;     time_t t = time(NULL);     tp = localtime(&t);      printf("%d/%d/%dn",tp->tm_mon+1,tp->tm_mday,tp->tm_year+1900);     printf("%d:%d:%dn",tp->tm_hour,tp->tm_min,tp->tm_sec);       return 0;  }