I am using Debian and my Postgresql was installed through the Debian package during the Debian installation.
Everything should be in default settings, after searching from google, the data directory is
/var/lib/postgresql/8.4/main
Then I type initdb -s to show the internal settings for reference. But it show me
initdb: no data directory specified
So, I follow the instructions at "postgresql.org/docs/8.4/interactive/creating-cluster.html" (sorry,new guys can't use url link, this site rule, add www. at the front pls) and try initdb -s again, but give me the same result.