How to check automatically if CVS update gave error or failed

[Ashutosh]

Hello friends,

I am automating a task where CVS update gives errors or fails. My goal
is to silently check if there is any error in CVS update. If there is
no error do nothing. But if there is any error, sent email
notification and take corrective action to perform CVS update again.

I am executing cvs update command in .sh script.

I am willing to know is this automation possible?
If Yes can you please provide any hint?

Thanks in advance,

Regards
Ashutosh