What best practices can PHP developers follow to ensure smooth functioning of their scripts even after changes in file permissions by the hosting provider?

When hosting providers change file permissions, PHP scripts may encounter issues accessing or modifying files. To ensure smooth functioning, PHP developers can use the `chmod` function to set appropriate permissions for files and directories within their scripts. By explicitly setting permissions within the code, developers can maintain control over file access regardless of changes made by the hosting provider.

// Set file permissions using chmod
$filename = 'example.txt';
$permissions = 0644; // Set appropriate permissions for the file

if (file_exists($filename)) {
    chmod($filename, $permissions);
} else {
    echo 'File does not exist.';
}