How get the time in milliseconds in FreeBSD?

问题:

In Linux I can find the current time in milliseconds using the command:

date +%s%N

but on FreeBSD I get only

[13:38 ]#date +%s%N
1299148740N

How can I get the time in milliseconds (or nanoseconds) in FreeBSD?

回答1:

Use gettimeofday(), for example:

#include <stdio.h>
#include <sys/time.h>
int main(void)
{
  struct timeval time_now;
    gettimeofday(&time_now,NULL);
    printf ("%ld secs, %ld usecs\n",time_now.tv_sec,time_now.tv_usec);

    return 0;
}

回答2:

The BSD date command doesn't support milliseconds. If you want a date with millisecond support, install the GNU coreutils package.

I encountered this on OS X, whose date comes from BSD. The solution was to brew install coreutils and ln -sf /usr/local/bin/gdate $HOME/bin, and making sure that $HOME/bin comes first in PATH.

回答3:

Try using tai64n from daemontools:

$ echo | tai64n | tai64nlocal
2011-03-03 09:45:37.833010500

$ ps | tai64n | tai64nlocal
2011-03-03 09:52:30.817146500   PID TTY          TIME CMD
2011-03-03 09:52:30.817150500  7154 pts/1    00:00:07 bash
2011-03-03 09:52:30.817157500 20099 pts/1    00:00:00 ps
2011-03-03 09:52:30.817159500 20100 pts/1    00:00:00 tai64n
2011-03-03 09:52:30.817162500 20101 pts/1    00:00:00 tai64nlocal

回答4:

Here's a one-liner for any recent Perl:

perl -MTime::HiRes=gettimeofday -MPOSIX=strftime -e '($s,$us) = gettimeofday(); printf "%d.%06d\n", $s, $us'
1487594425.611120

(modified from this answer to a similar question)

回答5:

Another way to get milliseconds is to use Python:

time_ms=$( python3 -c'import time; print(time.time())' )
echo $time_ms

Outputs:

1570807434.2774572

Note that python 2.x only returns 100ths of a second. May need to be tweaked slightly if your OS is using only Python 2.x to get more granularity.