question on cut

[geisj at pagestation.com (Jerry Geis)]

I am trying to use cut to tell me the suffix of a file.
for example: echo /home/silentm/log/file.machine.log | cut -d . -f 1-

I was expecting to get .log or log but I get the entire string echoed back.

doing the opposite gave me what I expected:
echo /home/silentm/log/file.machine.log | cut -d . -f 1
gives me
/home/silentm/log/file

I am trying to find a way to test if the file ends in .log?

How might I do that.

Thanks,

Jerry