How to determine the user that called a stored proc 1

[ddiamond]

My platform is AS400 V5R4 DB2.

Is it possible for a sql stored procedure or stored function to determine what userid executed it? For example in oracle you could use the following select:

select user from dual ;

Is there anything equivalent for DB2?

 

[Mercury2]

The UserId is in the USER special register. The data type of the special register is VARCHAR(18).

 

[ddiamond]

Thanks Mercury2. That was easy.