[PHP] Download/upload large file by chunks

large_file_by_chunks.php

<?php 

const CHUNK_SIZE = 50 * 1024 * 1024;
   
function Download(string $url, string $filename) : bool {
    $inputHandler = fopen($url, "r");
    $fileHandler = fopen($filename, "w+");
    if ($inputHandler === false || $fileHandler === false) {
        return false;
    }

    while (true) {
        $buffer = fgets($inputHandler, CHUNK_SIZE);
        if (strlen($buffer) == 0) {
            fclose($inputHandler);
            fclose($fileHandler);

            return true;
        }

        fwrite($fileHandler, $buffer);
    }
}

function Upload(string $filename) : void {
        $handle = fopen($filename, "rb");

        if ($handle === false) {
            return;
        }

        while (feof($handle) === false) {
            echo fread($handle, CHUNK_SIZE);
            ob_flush();
            flush();
        }
    }