How can file permissions and directory access impact the successful inclusion of PHP files in a web server environment?

File permissions and directory access can impact the successful inclusion of PHP files in a web server environment because if the permissions are not set correctly, the web server may not be able to read the files or access the directories where the PHP files are located. To solve this issue, you need to ensure that the file permissions are set to allow the web server to read the files and that the directories have the necessary permissions for the web server to access them.

// Set file permissions to allow the web server to read the file
chmod("example.php", 0644);

// Set directory permissions to allow the web server to access it
chmod("directory", 0755);