Question

man 2 stat表示st_atime中返回的值st_mtime，st_ctime和struct stat属于time_t类型，其分辨率为秒。如何以更高的分辨率获得相同的值，可能是struct timespec或struct timeval，或只是丢失的亚秒部分？

我需要这个用于Linux上的C ++，但我也用C标记，因为我认为两种语言的答案可能相同。

Answer 1

根据man 2 stat的注释部分：

   Since kernel 2.5.48, the stat structure supports nanosecond resolution  for  the  three  file  timestamp  fields.   Glibc
   exposes the nanosecond component of each field using names of the form st_atim.tv_nsec if the _BSD_SOURCE or _SVID_SOURCE
   feature test macro is defined.  These fields are specified in POSIX.1-2008, and, starting with version 2.12,  glibc  also
   exposes  these  field  names if _POSIX_C_SOURCE is defined with the value 200809L or greater, or _XOPEN_SOURCE is defined
   with the value 700 or greater.  If none of the aforementioned macros are defined, then the nanosecond values are  exposed
   with names of the form st_atimensec.  On file systems that do not support subsecond timestamps, the nanosecond fields are
   returned with the value 0.

如何以最大分辨率获取文件时间戳？

1 个答案: