This is A functions to register a Custom post in wordpress.
add_action( 'init', 'sonia_custom_post' );
function sonia_custom_post() {
register_post_type( 'post_name',
array(
'labels' => array(
'name' => __( 'Sonia' ),
'singular_name' => __( 'sonia' ),
'add_new_item' => __( 'Add New post' )
),
'public' => true,
'supports' => array('author', 'thumbnail', 'title', 'editor', 'custom-fields'),
'has_archive' => true,
'rewrite' => array('slug' => 'post-item'),
)
);
}