Code
<?php
declare(strict_types=1);
// Komplett lesen
$content = file_get_contents(__DIR__ . '/config.txt');
// Zeilenweise (Memory-schonend)
$handle = fopen(__DIR__ . '/big.log', 'r');
while (($line = fgets($handle)) !== false) {
processLine(trim($line));
}
fclose($handle);
// Atomar schreiben (kein halbfertiger Zustand)
$tmp = tempnam(sys_get_temp_dir(), 'data');
file_put_contents($tmp, $content);
rename($tmp, __DIR__ . '/data.txt');