postmaster start problem

I killed the postmaster with kill -9. And when I restart the postmaster with default port, following error happened :

# nohup postmaster -i -S
FATAL: StreamServerPort: bind() failed: Address already in use
        Is another postmaster already running on that port?
        If not, remove socket node (/tmp/.s.PGSQL.5432) and retry.
/usr/local/pgsql/bin/postmaster: cannot create UNIX stream port

I couldn't find the /tmp/.s.PGSQL.5432 to remove it.

What I can do to restart the postmaster wiht port 5432 ?

Sorry for my bad English.

Thanks