pg-bulkload

How do I specify columns when loading new rows into PostgreSQL using pg_bulkload

I'm experimenting with using the pg_bulkload project to import millions of rows of data into a database. However, none of the new rows have a primary key and only two of several columns are avalable in my input file. How do I tell pg_bulkload which columns I'm importing and how do I generate the primary key field? Do I need to edit my...