How can permissions affect PHP file inclusion and access?

Permissions play a crucial role in PHP file inclusion and access. If a file has restrictive permissions set, PHP may not be able to include or access it, leading to errors or security vulnerabilities. To resolve this, ensure that the files being included have appropriate permissions set to allow PHP to access them.

// Set appropriate permissions for the file to be included
chmod("included_file.php", 0644);

// Include the file with the correct permissions set
include("included_file.php");