Operations with strftime

Anonymous Monk has asked for the wisdom of the Perl Monks concerning the following question:

Hi Perl Monks

I'm trying to get the timestamp of subrotine before and after its execution and determine its duration.

Currently, I'm doing this:


$time_start = strftime("%H:%M:%S", localtime(time));

&my_rotine();

$time_end = strftime("%H:%M:%S", localtime(time));

$duration = $time_end - $time_start;
[download]

However, i get a warning:

Argument "13:13:13" isn't numeric in subtration.

But the result is:

Start = 13:13:13 ; End = 13:13:15 ; Duration = 2

Is there a better way to do this?

Comment on Operations with strftime Select or Download Code

Replies are listed 'Best First'.
Re: Operations with strftime by Corion (Patriarch) on Jun 17, 2014 at 11:06 UTC
Strings do not work in subtraction. Maybe consider reading time to find out what the function returns. After that, it should be trivial to find out how to get the time taken. Update: ambrus found it for me - the most roundabout way to get an epoch timestamp would be `strftime( '%s', localtime( time ))` [download] ... but that's just identical to `time()`.	[reply] [d/l] [select]
Re^2: Operations with strftime by perlfan (Parson) on Jun 17, 2014 at 14:08 UTC
FWIW, `strftime` is damn handy for date subtraction and addition if you don't want to use heavy weighted modules like DateTime. I've had great success with it, see for more information: How Do I Get Yesterday's Date Using localtime. So in this case, `strftime` would be more useful if you had a date/time and an interval to add/subtract. There are many other modules and benchmarks for benchmarking. brian_d_foy has a great section on Benchmarking in his Mastering Perl book. For higher level profiling, you should look at Devel::NYTProf.	[reply] [d/l] [select]
Re: Operations with strftime by parv (Parson) on Jun 17, 2014 at 11:19 UTC
Try Time::HiRes to get the time difference via `&tv_interval`.	[reply] [d/l]
Re: Operations with strftime by Anonymous Monk on Jun 17, 2014 at 11:08 UTC
However, i get a warning: Yeah, strings aren't good for math operations :D Try storing time instead of stftime output Is there a better way to do this? Benchmark, it uses times	[reply]