Perl time

Process Time

Millisecond level process time

use Time::HiRes;
my $before = Time::HiRes::time;
# Process
my $after = Time::HiRes::time;
printf("DiffTotal %f\n", $after - $before);

sleep

sleep 1;

Sleep second; second is sleeping time.

Wait less than 1sec

Use Time::HiRes

Time::HiRes::sleep(0.5);