Applications Messaging Standard

[Alasdair Allan]

Mark Taylor wrote:
> However, I think the two points that John raises are important  
> ones, especially the one about what you do on a multi-user machine,  
> or more generally, if the well-known port earmarked for the service  
> is already in use.

This is a crucial point, we can't assume that the user can talk to a  
"general user" daemon, we aren't looking at a service here.  
Everything has to take place in user space, so we can't assume that  
the 'hub' is up and running continuously. We have to assume that the  
hub is (mostly) started by the user in some fashion, there may be  
multiple users on the same machine. The "well known" port may be in  
use, so there has to be some way to communicate this to the user, and  
to applications looking to connect to that user's hub (not somebody  
else's hub that's running on the same machine, but the hub that the  
user started)...

> My feeling is still that the file-based approach, while inelegant,  
> presents fewer problems in practice than the socket-based one, but  
> I am prepared to have my opinion changed.

I don't see any way around using a file to solve this problem, I'd  
welcome persuasion, but a file based approach to communicate this one  
piece of vital information seems to be the only way around it.  
Everything else, of course, should go down the wire.

Al.