Re: Interesting things from the Plan 9 rc manpage

[Paul Haahr <haahr@mv.us.adobe.com>]

> A new process would share the
> namespace of its parent, including /env, so there's no work that needs
> to be done by any party.

yes, but a shell typically reads its entire environment on startup, and
all those readdir(), open(), read(), and close() operations can't be free.
on the other hand, if they don't cache the environment in the shell,
every reference to an environment variable has to do 3 system calls
(open, read, close), which is painful in my mind, but maybe rob's right
when he says you shouldn't worry about system call overhead.

thinking about it, they probably have to use the latter approach, because
otherwise you can't take advantage of the sharing of environments between
processes that plan 9 offers.

anyway, this is all idle speculation.