How do I change the post title's link on the posts page?

Question

I created a plugin that if the post is in a certain category, it will change the content to display a login message if the user is not logged in. How can I change the post title's link from my plugin?

Note: My code is at https://github.com/NerdOfLinux/MemberOnly/

If you know the plugin Ultimate Member, I want something similar to their custom post settings to only allow logged in users to access the post, and redirect users who are not logged in to the login page.

Answer 1

Use the post_link filter hook:

add_filter( 'post_link', 'wpse_change_post_link', 99, 3 );

function wpse_change_post_link( $url, $post, $leavename = false ) {
    // Can't fill these conditions since you didn't specify them...
    if ( 'my_post_type' === $post->post_type ) {
        $url = ''; // Your new URL...
    }

    return $url;
}