Programs on our web server machine recently started complaining aboutbeing unable to set up semaphores (well, once we figured out what theerror message meant). This rapidly sent us on an expedition into theunderdocumented mists of the kernel.sem sysctl, and so I'll writedown what I've learned about what I think is going on.

In the grand style of System V IPC in general, what programs allocateis not semaphores, but semaphore arrays (officially called 'semaphoresets'). A semaphore

Here's something that I am surprised is not already in the Pythonstandard library: a simple module to generate and assemble HTMLfragments (or if you prefer, general XML fragments), up to and includingfull HTML pages.

I find it especially surprising because not only is this somethingthat a lot of people wind up needing to do sooner or later (considergenerating error pages from inside a simple CGI program), but there'seven a very common simple model for it that everyone seems to writetheir

I know, NFS has a lot of new security features in both the more or lessmythical NFS v4 and in NFS v3 with some hacks. The problem is that theyall give me the wrong sort of security (as far as I can tell); likeother real network filesystems, they're all focused on authenticatingthe users. What I want is good authentication of the hosts.

(The problem with user-based authentication is that it takes out allforms of setuid . This forces a really

Given both the need for certificate authorities and the practical weaknesses that they have, it would be niceif it was easy to drop a CA without causing massive havoc. The moststraightforward way to implement this is to allow SSL certificates to besigned by more than one authority, and to be considered valid if any ofauthorities is trusted.

The problem with this is economic. Each CA is going to have to chargeyou their own payment in order to sign your certificate, which meansthat most people will never buy this