human
Considering the provided database schema and associated query, produce SQL code to retrieve the answer to the query. 
###Database Schema: PowerShell (Cmdlet), PowerShell (Alias), CMD.EXE / COMMAND.COM, Unix shell, Description
###Question: What are all values of CMD.EXE / COMMAND.COM for the unix shell echo?
gpt
SELECT CMD.EXE / COMMAND.COM FROM table WHERE Unix shell = echo