Micro/milliseconds since epoch

[Jakes Louw]

Hi all

I'm looking for a utility or script that will return milliseconds or preferably microseconds from epoch until present, or until a specific date.

On mainframes, we had "dateandtimeinmicroseconds", but I know nothing like that exists on standard HP-UX.

[Mark Grant]

You don't have a utility as such but there is the 'C' gettimeofday() function.

Here is a bare bones example of how you might use it. Beware, I haven't actually tried to compile this :)

#include

main(){

struct timeval t;
struct timezone tz;

gettimeofday(&t,&tz);
printf("Time in seconds is %ld and %ld micro-seconds\n",t.tv_sec,t.tv_usec);
}

[Ross Barton · Accepted solution]

See also the thread http://forums.itrc.hp.com/service/forums/questionanswer.do?threadId=602110

#include

struct timeval now;
struct timezone timezone;

gettimeofday(&now,&timezone);

/* now.tv_sec is seconds since EPOCH
(1/1/1970 00:00:00) */

/* now.tv_usec is microseconds in the current second */

do a man on "gettimeofday" and have a look in the time.h include file for more info and details of the structures.
Note: Microseconds are not always accurate to the microsecond - there is some small error involved in the CPU calculating this. However, it would be insignificant in the calculation of milliseconds from microseconds. This error can be significant in calculation of timestamps for things like auditing software or flight simulations etc.

Enjoy
Rossco