How can PHP developers prevent users from uploading files without file extensions and ensure proper file handling?

To prevent users from uploading files without file extensions and ensure proper file handling, PHP developers can validate the file extension before allowing the upload. This can be done by checking the file's MIME type or using a whitelist of allowed file extensions. Additionally, developers should sanitize the file name to prevent any potential security vulnerabilities. 

// Validate file extension before allowing upload
$allowedExtensions = array('jpg', 'jpeg', 'png', 'gif');
$uploadedFile = $_FILES['file']['name'];
$extension = pathinfo($uploadedFile, PATHINFO_EXTENSION);

if (!in_array($extension, $allowedExtensions)) {
    // File extension is not allowed, handle the error accordingly
    die('Invalid file extension. Allowed extensions are: jpg, jpeg, png, gif');
}

// Sanitize the file name to prevent any potential security vulnerabilities
$cleanFileName = preg_replace("/[^a-zA-Z0-9.]/", "_", $uploadedFile);

Keywords

PHP file uploads file extensions validation error handling

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