> netstat -nap | grep mysql
tcp6  0    0 :::3306   :::*       LISTEN        80185/mysqld
unix  2    [ ACC ]    STREAM     LISTENING     2499807  80185/mysqld      /var/run/mysqld/mysqld.sock
unix  3    [ ]        STREAM     CONNECTED     2678908  109866/mysql
unix  3    [ ]        STREAM     CONNECTED     2678296  80185/mysqld      /var/run/mysqld/mysqld.sock
unix  3    [ ]        STREAM     CONNECTED     2677308  80185/mysqld      /var/run/mysqld/mysqld.sock
unix  3    [ ]        STREAM     CONNECTED     2674988  109818/mysql

mysql> use mysql;
mysql> select user, host from user where user='testdbuser';
+------------+----------------+
| user       | host           |
+------------+----------------+
| testdbuser | %              |
+------------+----------------+