Subject: Re: kernel vs boot-program
To: None <>
From: Ty Sarna <>
List: tech-kern
Date: 03/14/1994 23:32:00 wrote:
> Where do you do the expansion?  Only in symbolic links?  That way the changes
> fit "neatly" into the fs-independent namei code and it suddenly works across
> all fs types.

Currently the expansion happens in all filenames, not just in symbolic
links. This is consistent with AFS (which is my goal) and provides
better consistency. Only four variables are expanded: @sys, @host,
@machine, and @arch. @sys is the most commonly used, and is replaced
with a "sysname", ie i386_netbsd09a or what have you. Again, like AFS.
There are not environment expansions, so there are no security concerns,
and no worries about getting them set in the first place.

Like fork(), filename component expansions in the kernel may seem ugly
and unatural to some, but once you've actually tried it you appreciate
the elegance of the solution.  @sys in particular makes multi-arch
administration a dream.  It's ever so much easier and cleaner than
automounter hacks, tangled jungles of symbolic links, etc.

Ty Sarna                 "As you know, Joel, children have always looked        up to cowboys as role models. And vice versa."