WordPressで一番親のディレクトリ名を取得する。サブディレクトリインストール型対応。

gistfile1.php

<?php
/**
 * get_second_directory
 */
function get_second_directory() {
	if ( $_SERVER['REQUEST_URI'] ) {
		$home_url = home_url();
		$home_url = explode( '/', $home_url );
		$REQUEST_URI = $_SERVER['REQUEST_URI'];
		$REQUEST_URI = preg_replace( '/^(.*)?\?.*$/', '$1', $REQUEST_URI );
		$REQUEST_URI = trim( $REQUEST_URI, '/' );
		$directories = explode( '/', $REQUEST_URI );
		$over = 0;
		if ( count( $home_url ) >= 4 ) {
			$over = count( $home_url ) - 3;
		}
		foreach ( $directories as $directory ) {
			if ( $directory ) {
				if ( $over ) {
					$over --;
					continue;
				}
				return $directory;
			}
		}
	}
}