Is there a way to distinguish user switching from regular logins?

[therealgilles]

I would like to keep tracks of regular user logins and filter out user switching logins. Is there a way to do that? Thanks for any advice :)

[johnbillion]

Yep this is possible. If you use the authenticate filter or the wp_login action then those only fire when a user actually logs in, not when a user switches.

If you use the set_auth_cookie action then that will also fire when a user switches. In that case I don't believe you can determine at that point whether the user is logging in or switching because the corresponding $_COOKIE values won't be updated at that point.