new row in text area

i have a textarea where i want to do when a user is writing something and pressing enter to take him to a new line and after publishing to look exactly as he wrotes
i’m new to this, i think this is the line

if ($type=='long text'){
                print '<textarea type="text" class="form-control"  id="'.$slug.'"  size="0" name="'.$slug.'" rows="5" cols="42">'.$custom_fields_array[$slug].'</textarea>';
           }else{
                print '<input type="text" class="form-control"  id="'.$slug.'" size="40" name="'.$slug.'" value="'.$custom_fields_array[$slug].'">';