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: How many values of powershell (cmdlet) are valid when unix shell is env, export, set, setenv?
gpt
SELECT COUNT PowerShell (Cmdlet) FROM table WHERE Unix shell = env, export, set, setenv