starting the postmaster

I just upgraded to RedHat 7.2 and I'm having a problem starting the postmaster with the -i argument for tcpip.

The /etc/rd.d/init.d/postgresql file has a line in it like this:

su -l postgres -s /bin/sh -c "/usr/bin/pg_ctl -D $PGDATA -p /usr/bin/postmaster start > /dev/null 2>&1" < /dev/null

if I insert an -i before the -D... or after it... or behind the -p or where ever it fails.

have been messing with the script... trying different things that I find in the documentation, some of it from my imagination. Some of it works... but hangs the boot process at startup

What's the correct way to do this?

thanks,
Brian