How to check whether PostgreSQL server is up and running?

Hi,

After having various error message in starting PostgreSQL version 8.2.11; finally uninstalled/deleted it. Now trying my luck on  8.3.7, but things haven't changed for me.
When I try to check that postmaster server is running or not? I get the following error:
$ postmaster -D /usr/local/pgsql/data
LOG:  could not translate host name "localhost", service "5432" to address: Name or service not known
WARNING:  could not create listen socket for "localhost"
FATAL:  could not create any TCP/IP sockets
.......................................................................
Similarly when I try to start postgres server with
[postgres(at)callisto postgresql-8.3.7]$ pg_ctl -D pg8 start
postgres cannot access the server configuration file "/usr/local/pgsql/postgresql-8.3.7/pg8/postgresql.conf": No such file or directory
server starting

Have no idea what's wrong and where the problem is? Do I need to change/edit some of Environment variable settings or what? Or should I reinstall PostgreSQL with Yum?? Or should give up using PostgreSQL and switch to some other DB like MySQL etc... No idea what to do.....?

Thanks in advance for help.

-Jan Muhammad