The normal operation of our servers is to have tcpip_sockets enabled,

The normal operation of our servers is to have tcpip_sockets enabled,
but occasionally I may need to shut down the server and restart it
w/o tcpip sockets. Postmaster has the -i option to turn on tcpip
connections, but it wasn't immediately clear how to easily or
temporarily turn it off (when it's been enabled in postgresql.conf).

In fact, it wasn't clear to me until digging in to postmaster.c that
I could pass '-c tcpip_socket=false' or '--tcpip_socket=false'.
(And then of course when I looked more closely at the man page I
realized I'd missed the proper part of the documentation.) What I'd
been looking for is a flag that would have the opposite effect of
'-i', and it's conceivable that others will be looking for specific
flags to do the opposite of '-F' and '-S'.

I was preparing to add options to postmaster until I realized that
maybe the solution is just to add some documentation.

If you'd rather have 1 character options to accomplish this, I'd be
happy to do that-- adding those 9 lines of code is definitely within
my ability. :)  (Although, the "right" letter to be the opposite of -S
isn't clear to me, since -s is already taken.)

Ron Snyder.