What are the drawbacks of developing custom FTP programs in PHP for uploading large files, and how can these be mitigated for better performance and security?

Developing custom FTP programs in PHP for uploading large files can lead to performance issues due to PHP not being optimized for handling large file uploads efficiently. Additionally, security vulnerabilities may arise if the code is not properly sanitized and validated, potentially leading to attacks like directory traversal or file injection. To mitigate these drawbacks, consider using dedicated file transfer protocols like SFTP or FTPS for better performance and security, and implement proper input validation and security measures to prevent potential attacks.

// Example of using SFTP to upload a file securely
$connection = ssh2_connect('example.com', 22);
ssh2_auth_password($connection, 'username', 'password');

$sftp = ssh2_sftp($connection);
$stream = fopen("ssh2.sftp://$sftp/path/to/remote/file", 'w');

$localFile = 'path/to/local/file';
$fileContent = file_get_contents($localFile);

fwrite($stream, $fileContent);
fclose($stream);