Printing Current User Name using PHP

I gave it my best try all day today to get this php code to print out the current user’s name at the top of my blog ~ very similar to the top line in the dashboard (Howdy, [User Name] | Profile | Log out).

I was able to get it to print out everything EXCEPT the name of the current user (It just prints “Howdy ” but no name. Also it doesn’t recognize my class that I am trying to add to the dividing “|”‘s. I just want to make them a different color using a class.

<span class="login_container">
	         <?php global $user_ID;
                        if ($user_ID) {
                            echo "Howdy "; echo $user_identity; echo '<class="login_light">' . " | ";
                            } 

                        wp_register('<class="login">'); {echo " | ";}

						if($user_ID) {
							echo '<class="login"><a href="' . site_url('wp-login.php?action=logout', 'login') . '">' . __('Log Out', 'atahualpa') . '</a>';
						} else {
							echo '<class="login"><a href="' . site_url('wp-login.php', 'login') . '">' . __('Log In', 'atahualpa') . '</a>';
						}
		    ?>

	    </span>

Any help would be much appreciated. Thank you.
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