How can you ensure that only the PHP file can write to a specific directory and not others?

To ensure that only the PHP file can write to a specific directory and not others, you can utilize file permissions. Set the directory permissions to allow only the owner (PHP file) to write to it, while restricting write permissions for others. This can be achieved by setting the directory permissions to 700, which gives full permissions to the owner and no permissions to others.

// Set the directory path
$directory = '/path/to/directory';

// Set the directory permissions to allow only the PHP file to write to it
chmod($directory, 0700);