What are the best practices for using file_put_contents() and file_get_contents() in PHP to ensure data integrity and security?

When using file_put_contents() and file_get_contents() in PHP, it is important to ensure data integrity and security by properly sanitizing and validating input data. To prevent potential security vulnerabilities such as directory traversal attacks, it is recommended to use absolute file paths and restrict access to sensitive files. Additionally, using file locking mechanisms can help prevent data corruption in case of simultaneous write operations.

// Example of securely using file_put_contents() to write data to a file
$file = '/path/to/your/file.txt';
$data = 'Hello, World!';

// Ensure file path is absolute and restrict access to sensitive files
if (strpos($file, '/path/to/your/') === 0) {
    // Use file locking to prevent data corruption during simultaneous write operations
    if ($handle = fopen($file, 'w')) {
        if (flock($handle, LOCK_EX)) {
            file_put_contents($file, $data);
            flock($handle, LOCK_UN);
        }
        fclose($handle);
    }
}