Specifying (set of random) port numbers for the help HTML server (Was: Re: Fixing html help port in 2.10)

On Fri, Oct 16, 2009 at 7:54 AM, Duncan Murdoch <murdoch at stats.uwo.ca> wrote:

On 10/16/2009 10:39 AM, Dieter Menne wrote:

I noted that the new html-help in 2.10 under Windows uses a random port on
my
computer.
This cause a problem, because when I create a link such as:

http://127.0.0.1:28027/library/stats/html/addmargins.html

this is for one-time use only. Is it possible to fix the port?

Not currently.  If you look in tools:::startDynamicHelp you can see how it
is set up; you could duplicate that setup as a temporary workaround.  You
might be better off to build R with static help instead.  What is the
application where you want to be able to give out links?  Perhaps we could
consult an environment variable or option() to choose the port instead of
leaving it completely random.

The reason it is random is the worry that multiple R instances on the same
machine might collide.  All processes on the machine see the same ports.

Related:
I'd like to suggest an option/environment variable that specifies the
set of port numbers sampled from, e.g. 6800:6850 or similar.

The reason is that in some places, the user don't have admin
privileges on the computer and most/all ports are blocked from running
servers, and there is a sysadm that needs to approve each port to be
unblocked.  With such a security polices it is possible to have the
smaller set of port number unblocked (but not the full 0-65535 range).
 This applies at least to "regular users" on Windows.

My $.02

/Henrik

Duncan Murdoch