如何更新时间戳文件--utimes（）简单介绍

这两天遇到一个问题，需要设置一个时间戳文件，并且需要在需要的时候更新该时间戳文件，并比较上一次更新时间以及此次更新时间的差值，并打印出来。

下面是简单的步骤，相关代码如下：

#include <utime.h>
#include <time.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#define TIME_STAMP "/root/charliye/time_flag"
main()
{
  struct stat buf1;
  struct stat buf2;
  time_t t_old,t_old1,t_now,t_new;
  stat(TIME_STAMP , &buf1); //获取时间戳文件的相关信息存到buf1

  t_old = buf1.st_mtime;
  t_old1 = buf1.st_atime;
  printf("the last modify time is : %u,%u\n", t_old,t_old1);
  t_now = time(NULL);
  printf("the current time is : %u\n", t_now);
  int ret = utimes(TIME_STAMP, NULL); //更新时间戳文件为当前时间
  stat(TIME_STAMP, &buf2); //获取当前时间戳文件的相关信息存到buf2
  t_new = buf2.st_mtime;
  printf("the new modify time is : %u\n", t_new);
}

程序运行结果如下：

[root@localhost charliye]# ./utime
the last modify time is : 1456380013,1456380013
the current time is : 1456380015
the new modify time is : 1456380015
[root@localhost charliye]# ./utime
the last modify time is : 1456380015,1456380015
the current time is : 1456380021
the new modify time is : 1456380021
[root@localhost charliye]# ./utime
the last modify time is : 1456380021,1456380021
the current time is : 1456380031
the new modify time is : 1456380031
[root@localhost charliye]# ./utime
the last modify time is : 1456380031,1456380031
the current time is : 1456380044
the new modify time is : 1456380044