301 redirect from old URL structur to new

Question

I recently updated the permalink structure of a website from /%postname%/ to /%category%/%postname%/ this is obviously causing 404 errors. Instead of writing 301 redirects for each post is there any way to do this in a more automated fashion, within WordPress? I essentially want to programmatically 301 redirect the URIs from the old permalink structure to the new one.

Answer 1

You can make a catch on 404 in wordpress with filter 404_template

Or you can use redirection plugin: http://wordpress.org/plugins/redirection/screenshots/ with Regex.

Can you follow the link in this Question: Catch 404 after changing permalink structure from /%postname%/ to /%category%/%postname%/

Answer 2

/**
 * Redirect a "/%postname%/" permalink structure to the their new URL.
 * 
 * @link http://wordpress.stackexchange.com/q/136306/1685
 */
function wpse_136306_redirect() {
    global $wp;

    // Check that we've hit a 404 for a non-empty permalink without slashes
    if ( is_404() && strlen( $wp->request ) && strpos( $wp->request, '/' ) === false ) {
        // Attempt to find a post that matches the request.
        $posts = get_posts(
            array(
                'posts_per_page' => 1,
                'name' => $wp->request,
            )
        );

        if ( $posts && $url = get_permalink( $posts[0]->ID ) ) {
            // All good, let's redirect to the new URL.
            wp_redirect( $url, 301 );
            exit;
        }
    }
}

add_action( 'template_redirect', 'wpse_136306_redirect', 1 );

Answer 3

If you are OK with a Wordpress plugin , you can use the WP redirection plugin.

Regular expressions are your friends https://redirection.me/support/redirect-regular-expressions/

In the Source URL, set .*

In Target URL, set /category/$1 . The tricky part is your category is a variable.