Might this be a firewall-like issue and nothing to do with html or R? If I understand the 2.10 help system, it operates by starting R as an http server - effectively a web server, operating on the local machine (127.0.0.1) with an unusual IP port (which doesn;t seem to be consistent from one run to the next, perhaps because it's taking a randomly or first available port in the high range). That established R as the default server for http requests made to the machine with the particular port specified, yes?
The 'obvious' OS-related thing that could break this is a firewall restriction on access to http on ports other than 80 and 8080, the typical default ports. That could arise either because of incoming or outgoing IP port resrtrictions; the firewall could either stop an application asking for an odd port, or could stop R serving it. It's unusual for a firewall to prevent access to th elocal host (127.0.0.1) but it might be worth checking. It could be fixed (or at least checked) by looking at the firewall settings to see whether there were any port-specific restrictions (eg 'only allow http on ports 80 and 8080' or equivalent). Another possibility is to check the browser and OS http proxy options; if they are set to point to a proxy _every time including local access requests_ you'll presumably have similar problems. Incidentally, i haven;t yet broached the idea of R acting as an http server every time it calls help with our IT security folk; I'm rather afraid of the possible consequence. Call me paranoid if you like ... but the depth of explanation they might require could be daunting. Steve Ellison >>> Duncan Murdoch <[email protected]> 04/02/2010 00:45:21 >>> On 03/02/2010 7:17 PM, Jonathan wrote: > Duncan: > I suspect that you're right about the file association having been the > issue. .html files were not associated with either browser. However, I > fixed that by associating .html files with Firefox, but R still gave me the > same error! If that was the problem, R didn't realize the association had > been changed. > > I tried uninstalling R and reinstalling R, thinking maybe it takes a > snapshot of associations once (at install), and keeps its own internal table > (even though that didn't sound all that intuitive). No luck; R still > persisted in being unable to open help files. R knows nothing about the associations. They are handled by the Windows shell functions. And it's not .html files; Windows recognizes that the URL is a URL, and sends it to whichever browser has registered itself to handle them. So you might fix things by deleting and re-installing Firefox, telling it to install itself as the default browser. (Or tell IE to reinstall itself as the default, if you really want to do that.) You can also set up a shortcut to a URL ("New shortcut" from the context menu on the desktop) and give it the URL that R tried. This isn't a solution at all, since the URL only works for the current R session unless you set it to a fixed one with options(help.ports=12345), but it might give some more insight into what's wrong. Duncan Murdoch > > Then I rebooted my machine. I'm still getting the same error. > Any other ideas? > > Thanks, > Jon > > On Wed, Feb 3, 2010 at 5:57 PM, Duncan Murdoch <[email protected]> wrote: > >> On 03/02/2010 5:14 PM, Jonathan wrote: >> >>> Rich: >>> Both IE and Firefox are unable to find the link you supplied. However, >>> that's only because I've restarted my R session since I pasted the error >>> output (and it appears that each time I restart R, the URL is slightly >>> different). This time, I get: >>> >>> ?sum >>> starting httpd help server ... done >>> Error in shell.exec(url) : >>> access to 'http://127.0.0.1:31836/library/base/html/sum.html' denied >>> --- >>> If I paste the new URL into either browser, I can read the entry without >>> issue. This is what I've been doing to read help entries, but it's >>> tedious >>> to copy and paste the URL into a browser every time I want to read the >>> entry >>> for a particular function.. >>> >>> Happy to hear any other ideas! >>> >>> >> What happens if you paste that into the "Run" box on the start menu? It >> looks to me as though the association between URLs and your browser is >> broken. >> >> Another likely problem is antivirus software. If you can temporarily turn >> it off, see if that helps. >> >> Duncan Murdoch >> > ______________________________________________ [email protected] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code. ******************************************************************* This email and any attachments are confidential. Any use...{{dropped:8}} ______________________________________________ [email protected] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
