namespace children ?namespace? ?pattern?
Returns a list of all child namespaces that belong to the namespace namespace. If namespace is not specified, then the children are returned for the current namespace. This command returns fully-qualified names, which start with ::. If the optional pattern is given, then this command returns only the names that match the glob-style pattern. The actual pattern used is determined as follows: a pattern that starts with :: is used directly, otherwise the namespace namespace (or the fully-qualified name of the current namespace) is prepended onto the the pattern.