<?php
$start = microtime(true);

$fpIn  = fopen('input.csv', 'r');
$fpOut = fopen('output-pure.csv', 'w');

while (($row = fgets($fpIn)) !== false) 
{
	$fields = explode(";", $row);
	fwrite($fpOut, 
		implode(
			";",
			array(
				"name"           => $fields[0],
				"firstname name" => '"'.$fields[1] ." ". $fields[0].'"',
				"kto"            => $fields[2],
				"blz"            => $fields[3],
				"amount"         => $fields[4]
			)
		)
	);
}

$end = microtime(true);

$duration = $end - $start;
echo "Duration: ".round($duration, 2) . "s".PHP_EOL;