BLOX dynamic urls with robots.txt

[bo0oost]

Say for example I have a file that google indexes called:

[test.com...]

How can I block all of the dynamic possibilities (C=1, C=2, etc).

I have searched and found different answers:

Disallow: /widgets.php?

and also

Disallow: /widgets.php?C=*

Which would be correct in the robots.txt file, or would they both be correct?

Thanks in advance.

[goodroi]

Please note this is google specific robots.txt advice since wildcards are not officially supported by the robots.txt standard.

Since your variations all seem to have C=. You can use this line to block all google from all urls with C=.
Disallow: /*C=*