seq -f "http://po.co/page_%03g.html" 1 100 | xargs -I {} curl -O {} --rate 10/12s -o /dev/nu

$array = array(1, 2, 3, 2, 4, 1, 5, 3);

// Count the occurrences of each value
$counts = array_count_values($array);

// Filter to keep only values with a count greater than 1
$duplicates_with_counts = array_filter($counts, function($count) {
return $count > 1;
});

// The keys of this filtered array are the duplicate values
$duplicate_values = array_keys($duplicates_with_counts);

echo "Original Array: ";
print_r($array);

echo "Duplicate Values: ";
print_r($duplicate_values);
?>

Output:

Original Array: Array
(
[0] => 1
[1] => 2
[2] => 3
[3] => 2
[4] => 4
[5] => 1
[6] => 5
[7] => 3
)
Duplicate Values: Array
(
[0] => 1
[1] => 2
[2] => 3
)

