WP_Rewrite::set_permalink_structure( string $permalink_structure )

1962	public function set_permalink_structure( $permalink_structure ) {1963		if ( $this->permalink_structure !== $permalink_structure ) {1964			$old_permalink_structure = $this->permalink_structure;1965			update_option( 'permalink_structure', $permalink_structure );1966 1967			$this->init();1968 1969			/**1970			 * Fires after the permalink structure is updated.1971			 *1972			 * @since 2.8.01973			 *1974			 * @param string $old_permalink_structure The previous permalink structure.1975			 * @param string $permalink_structure     The new permalink structure.1976			 */1977			do_action( 'permalink_structure_changed', $old_permalink_structure, $permalink_structure );1978		}1979	}