Write a Ruby Script that simulates a simple four function calculator without a memory. The operations you should implement are:

+ - Add

- - Subtract

/ - Divide

* - Multiply

Q - Quit Program Error message must be displayed when invalid command is used or attempt to divide by zero. Use a single character as the command for each operation. Heres a sample of the calculator in use:

Enter First Operand: 0

Enter Command (+ - * / C Q): +

Enter Second Operand : 12

Result = 12

Enter First Operand: -4

Enter Command (+ - * / C Q): -

Enter Second Operand : 12

Result = -16

Enter First Operand: 10

Enter Command (+ - * / C Q): *

Enter Second Operand : 5

Result = 50

Enter First Operand: 13

Enter Command (+ - * / C Q): /

Enter Second Operand : 3

Result = 4.333333

Enter First Operand: 13

Enter Command (+ - * / C Q): \

Enter Second Operand : 3

******* ERROR : \ is not a valid command *******

Enter First Operand: 28

Enter Command (+ - * / C Q): /

Enter Second Operand : 0

******* ERROR : Cannot divide by zero *******

Enter First Operand: 15

Command (+ - * / C Q) Q

End