postmaster start options on RedHat 7.2

I would like to add a couple of startup options to postgresql on my system,
but am having difficulty modifying the RedHat startup scripts (in
/etc/rc.d/init.d)

I would like to add -i to allow network connections and -l for ssl traffic

I think the line to modify is:
su -l postgres -s /bin/sh -c "/usr/bin/pg_ctl  -D $PGDATA -p
/usr/bin/postmaster start  > /dev/null 2>&1" < /dev/null

I tried
su -l postgres -s /bin/sh -c "/usr/bin/pg_ctl  -D $PGDATA -p
`/usr/bin/postmaster -i` start  > /dev/null 2>&1" < /dev/null
and
su -l postgres -s /bin/sh -c "/usr/bin/pg_ctl  -D $PGDATA -p
'/usr/bin/postmaster -i' start  > /dev/null 2>&1" < /dev/null
and
su -l postgres -s /bin/sh -c "/usr/bin/pg_ctl  -D $PGDATA -p
/usr/bin/postmaster -o "i" start  > /dev/null 2>&1" < /dev/null

with no luck


Suggestions?