What Are Last Steps Performed When PostgreSQL Starts?

We are running PostgreSQL 8.1.4 on Red Hat Enterprise Linux 4.0 platforms
that are deployed worldwide.

In our most recent release, we started using a Java tool called IZPack to
install and start up our application, including PostgreSQL. We are finding
that we need to slow down this Java tool as it installs our application,
since it appears the tool does not wait for each step in the install script
to complete before executing the next step. This is affecting a successful
install of PostgreSQL.

QUESTION: what are the few last steps that PostgreSQL does when it starts
up? I am looking for things that I can check to be sure it has completed
installation (from a script) before allowing the script to proceed to the
next step, like:
  - opening a socket
  - creating a PID file
  - etc.