I have set up Postgre database on my linux OS. It is working fine. The
problem is that i have created a user suppose 'gagan'.
Now what changes should i make in the pg_hba.conf and pg_shadow files
inorder to make password authentification for 'gagan' while accessing the
database from local unix socket.

presently i have following line in my pg_hba.conf file :
local all trust

regards
Gagan.