Error Trapping -duplicate keys

Help:

I'm using Perl to insert data from a log file, what I am doing is this
(Pseudocode):

If NOT (INSERT INTO myTABLE)
THEN UPDATE myTABLE
endIf

Now the code I have works except I get a console message:

DBD::Pg::st execute failed: ERROR: Cannot insert a duplicate key
into unique index visitor_pkey at ./inslog.pl line 147, <> chunk 4.

So, my question is how to I trap this error, keep it from being display as
it is not really an error if the insert fails?

Many thanks!

S. Douglas Smith Sr.
-------------------------------------------------------------------------------------------------

"Simplicity is the most difficult thing to secure in this world; it is the
last limit of experience, and the last effort of genius." George Sand