How to login with email only no username in wordpress

It’s possible, you must change the filter for the name.

// remove the default filter
remove_filter( 'authenticate', 'wp_authenticate_username_password', 20, 3 );
// add custom filter
add_filter( 'authenticate', 'fb_authenticate_username_password', 20, 3 );
function fb_authenticate_username_password( $user, $username, $password ) {

    // If an email address is entered in the username box, 
    // then look up the matching username and authenticate as per normal, using that.
    if ( ! empty( $username ) )
        $user = get_user_by( 'email', $username );

    if ( isset( $user->user_login, $user ) )
        $username = $user->user_login;

    // using the username found when looking up via email
    return wp_authenticate_username_password( NULL, $username, $password );
}



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http://wordpress.stackexchange.com/questions/51678/how-to-login-with-email-only-no-username

One Url to another url via htaccess

RewriteRule ^article/?$ http://www.new-domain.com/article/ [R=301,NC,L] # Permanent Move

If the move is permanent, append “=301” to the “R” flag to have Apache tell the browser the move is considered permanent. Unlike the default “R”, “R=301” will also tell the browser to display the new address in the address bar.

This is one of the most common methods of rewriting URLs of items that have moved to a new URL (for example, it is in use extensively on this site to forward users to new post URLs whenever they are changed).

 

 

https://www.addedbytes.com/articles/for-beginners/url-rewriting-for-beginners/

Listing all information about the users browser

echo $_SERVER['HTTP_USER_AGENT'] . "\n\n";

$browser = get_browser(null, true);
print_r($browser);