file modification time smaller than a second

thllgo · 03-17-2010, 02:00 PM

Hello,

Is it possible to get file modification times measured to less than a second? Like milisecond, nanosecond, 10th of a second.

troop · 03-17-2010, 02:07 PM

yes.

Quote:

%N nanoseconds (000000000..999999999)

Code:

date -r /tmp "+%s/%N"

get seconds since 1970-01-01 00:00:00 UTC/nanoseconds

thllgo · 03-17-2010, 02:56 PM

Thanks. Your fix would have worked if the file system actually recorded the time at that granularity when the file was created. I tried the command on several files and everyone came out to 0 nanoseconds. I don't believe that is a likely scenario. I'm bummed.

chrism01 · 03-18-2010, 04:05 AM

It depends on the filesystem

Quote:

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 either of the form st_atim.tv_nsec, if the _BSD_SOURCE or _SVID_SOURCE feature test macro is defined, or of the form st_atimensec, if neither of these macros is defined. On file systems that do not support sub-second timestamps, these nanosecond fields are returned with the value 0.

http://linux.die.net/man/2/stat

If you know any C you can try it ...