What are the best practices for handling file permissions in PHP applications?

File permissions are crucial for securing files in a PHP application. It is important to set appropriate permissions to ensure that sensitive files are not accessible by unauthorized users. Best practices include setting file permissions to restrict access based on the principle of least privilege, avoiding using overly permissive permissions, and regularly auditing and updating file permissions.

// Set file permissions to restrict access
chmod("sensitive_file.txt", 0600);