Add urls

<?php

add_action('admin_menu', 'campos_fuentes');
function campos_fuentes() {
        add_meta_box('aniadirfuntes','Fuentes','func_camp_fuentes','post','normal','high');
}

global $wpdb, $post;

function func_camp_fuentes() {
        $value1  = (get_post_meta($post->ID, aniadirfuntes, true));
        echo '<input type="text" name="fuente[]" id="aniadirfuntes" value="'.htmlspecialchars($value1).'" style="width: 200px;" />';
}


function aniadirfuentes(){
       $fuente=$_POST['fuente'];

       foreach($fuente as $url ) {
           $salidaenlace=parse_Url($url, PHP_URL_HOST);
           print '<a href='.$url .'>'.ucfirst($salidaenlace).'</a>';
           echo ", ";

       }
}

add_filter ('the_content', 'aniadirfuentes');

?>