How to measure time from adb shell with milliseconds resolution?

问题

How can I measure time from adb shell with milliseconds or nanoseconds resolution?

Usingdate +%.%N from adb shell returns 1401546811.N (seconds resolution) instead of something like 1401547289.231869798 (nanoseconds resolution).

How can I get either milliseconds or nanoseconds resolution from adb shell?

Is there some terminal program that I can use to give me this? I am able to measure time using System.currentTimeMillis() and System.nanoTime() from Android application code itself, but I also need something from within adb shell.

回答1:

mksh (the standard Android shell since version 4.0) has a built-in EPOCHREALTIME environment variable:

Time since the epoch, as returned by gettimeofday(2), formatted as decimal tv_sec followed by a dot . and tv_usec padded to exactly six decimal digits.

So the command to get epoch time with microsecond accuracy in Windows would be:

adb shell echo $EPOCHREALTIME

or in Linux:

adb shell 'echo $EPOCHREALTIME'

If you just need millisecond accuracy:

adb shell 'echo ${EPOCHREALTIME:0:14}'

Or just the milliseconds part to use with another time format:

adb shell 'echo $(date +%T)${EPOCHREALTIME:10:4}'

回答2:

Kind of solved my problem by using botbrew. Probably not idea, but at least it works for now. /data/botbrew-basil/init -- date +%s.%N -- returns nanosecond resolution.

回答3:

adb shell echo $EPOCHREALTIME gives you the time with micro seconds, (don't write it with '\' before the variable name)

来源：https://stackoverflow.com/questions/23971337/how-to-measure-time-from-adb-shell-with-milliseconds-resolution