WP: Insert File into Wordpress Media Library PHP

http://cube3x.com/2013/03/upload-files-to-wordpress-media-library-using-php/

<form action="upload_file.php" method="post" enctype="multipart/form-data">
    <label for="file">Filename:</label>
    <input type="file" name="myfile" id="myfile">
    <input type="submit" name="submit" value="Submit">
</form>

<?php
if ( ! function_exists( 'wp_handle_upload' ) ) require_once( ABSPATH . 'wp-admin/includes/file.php' );
$uploadedfile = $_FILES['myfile'];
$upload_overrides = array( 'test_form' => false );
$movefile = wp_handle_upload( $uploadedfile, $upload_overrides );
if ( $movefile ) {
    //file is uploaded successfully. do next steps here.
}

if ( $movefile ) {
    $wp_filetype = $movefile['type'];
    $filename = $movefile['file'];
    $wp_upload_dir = wp_upload_dir();
    $attachment = array(
        'guid' => $wp_upload_dir['url'] . '/' . basename( $filename ),
        'post_mime_type' => $wp_filetype,
        'post_title' => preg_replace('/\.[^.]+$/', '', basename($filename)),
        'post_content' => '',
        'post_status' => 'inherit'
    );
    $attach_id = wp_insert_attachment( $attachment, $filename);
}

?>