WordPress Snippet

*post_statusを変更する

<?php
$my_post= array( 'ID'=> 1502,'post_status'=> 'private' );
wp_update_post($my_post);
?>

独自のステータスを作成する

function my_custom_post_status(){
 register_post_status( 'unread', array(
 'label'=> _x( 'Unread', 'post' ),
 'public'=> true,
 'exclude_from_search'=> false,
 'show_in_admin_all_list'=> true,
 'show_in_admin_status_list'=> true,
 'label_count' => _n_noop( 'Unread <span class="count">(%s)</span>', 'Unread <span class="count">(%s)</span>' ),
 ) );
}
add_action( 'init', 'my_custom_post_status' );

http://codex.wordpress.org/Function_Reference/register_post_status(@codex)