Get time in milliseconds without an installing an extra package?

Question

How can I get the time in milliseconds in Perl without installing any extra package?

I am running Linux.

Solution

Time::HiRes has been part of the core since Perl 5.7.3. To check for its availability, check for the Perl version, perl -v, or try to use it with perl -e 'use Time::HiRes;', both from the command line.

Sample usage:

use Time::HiRes qw/ time sleep /;

my $start = time;
sleep rand(10)/3;
my $end   = time;

print 'Slept for ', ( $end - $start ) , "\n";

To build on Konerak's comment, if it isn't there or it cannot be used, use native Linux commands via backticks:

sub time_since_epoch { return `date +%s.%N` }

print time_since_epoch;

Comments

[JRFerguson]

To load and/or verify a module from the command line you can use: perl -MTime::HiRes -e 1 in lieu of: perl -e 'use Time::HiRes'

[Zaid]

@mob : Thanks for the correction. @James_R_Ferguson : I purposely left out the -M flag because I didn't want to confuse the questioner with the syntax (using 1 instead of '' is a nifty little tip though :).

[JJ Liu]

@Zaid thanks! is the value returned by calling time in milliseconds?

[Zaid]

@JJLiu : It's the time in seconds since Jan 1, 1970 (aka the epoch)