block permission in Drupal

is it possible in Drupal to show开发者_如何学JAVA a menu just to a special username?

Yes, you can do it without extra modules:

1. First, create a new role (in "Administer > User Management > Roles")

2. then assign this new role to the user you want to show the block to (in "Administer > User Management > Users")

3. then in the block's properties (at "Administer > Blocks"), select only that role in visibility options.