use strict;
use warnings;
use diagnostics;

use Time::HiRes qw( time );
my $start = time();
stringsNthings();
your actual code goes here;
whether it be system(whatever_prog, whatever_arg);
or
sub stringsNthings{

    my $hello_world = "hello world\n";
    my $sum = 1 + 2;
    chomp(my name = <STDIN>);
}
print stringsNthings($hello_world);
print stringsNthings($sum."\n");
print stringsNthings($name);

my $end = time();
my $runtime = sprintf("%.16s", $end - $start);
print "This script took $runtime seconds to execute\n";