How can file permissions impact PHP scripts and what are best practices for handling them?

File permissions can impact PHP scripts by restricting or allowing access to files and directories. It is important to set appropriate permissions to ensure that sensitive files are not accessible by unauthorized users. Best practices include setting permissions to the minimum necessary level for functionality, avoiding giving global write permissions, and regularly reviewing and updating permissions as needed.

// Example of setting file permissions to restrict access
chmod("/path/to/file.php", 0644);