psql command error.

Hi,

I am stuck with an error as follows. I am trying to create a user with
'createuser' command. Also the same error is thrown even when I am trying to
run the 'psql' command.

$ createuser uss
Shall the new user be allowed to create databases? (y/n) y
Shall the new user be allowed to create more new users? (y/n) n
psql: connectDBStart() -- connect() failed: No such file or directory
Is the postmaster running locally
and accepting connections on Unix socket '/tmp/.s.PGSQL.5432'?
createuser: creation of user "uss" failed

Administrator(at)ANILJ ~
$ psql
psql: connectDBStart() -- connect() failed: No such file or directory
Is the postmaster running locally
and accepting connections on Unix socket '/tmp/.s.PGSQL.5432'?

Administrator(at)ANILJ ~
$

I searched the directory /tmp/, but the .S.PGSQL.5432 file doesn't exist.

regds,
-anil.