#!/usr/bin/perl 
use warnings; 
 
#code to determine primes 
 
print "find primes between 2 and ?\n"; 
$upper = <STDIN>; 
 
@range = (3..$upper); 
@primes = (2); 
 
foreach my $n (@range){       #for every entry of @range, $n) 
	foreach my $m (@primes) {		#for every number in @primes 
		if ($range[$n] % $primes[$m] == 0){ 
		}    	 #if $n modulo prime is zero 
								#do nothing 
		else {print "did we get here at least?"}#{@primes = (@primes, $n)}; #otherwise add $n to the list of primes 
	}; 
}; 
 
print "@primes\n";

use strict; 
use warnings; 
use integer; 
my @candidates; 
$#candidates = $ARGV[0] // 53; 
@candidates = 0..$#candidates;          # Init all candidates to prime 
for my $i (2 .. $#candidates) {         # Assume that 2 is prime 
    my $j = $i; 
    while ($j <= ($#candidates-$i)) { 
        $j += $i; 
        $candidates[$j] = 0;            # All multiples of $i are non-prime 
    } 
} 
my @primes = grep {$_} @candidates; 
print "@primes\n";

#!/usr/bin/perl 
 
use strict; 
use warnings; 
use Math::Prime::XS qw(primes); 
 
my $upper_limit = shift || 100; 
print "$_\n" for primes( $upper_limit );