In the context of PHP file deletion, how important is it to validate user input and implement additional security measures to prevent accidental data loss or unauthorized file removal?

It is crucial to validate user input and implement additional security measures when deleting files in PHP to prevent accidental data loss or unauthorized file removal. This can be achieved by verifying that the user has the necessary permissions to delete the file and sanitizing the input to prevent malicious file names.

<?php
$filename = $_POST['filename'];

// Validate user input and check permissions before deleting file
if (file_exists($filename) && is_writable($filename)) {
    unlink($filename);
    echo "File deleted successfully.";
} else {
    echo "Unable to delete file. Please check file permissions.";
}
?>