Thoughts on Multi-Symlink Concept

Willem Jan Withagen wjw at digiware.nl
Sat Feb 22 23:06:53 UTC 2014


On 16-2-2014 6:16, Perry Hutchison wrote:
> Jordan Hubbard <jordan.hubbard at gmail.com> wrote:
> 
>> Even variant symlinks (/bin -> /${ARCH}/bin), which can expand
>> differently depending on the user context, have clearly
>> understandable semantics - you know that the symlink is going
>> to expand to exactly one file no matter what ARCH is set to.
> 
> s/file/pathname/
> 
> Depending on what ARCH is set to, the expanision may or may not
> point to any actual file (or directory, or ...)

Yes, please can we get these ....

Apollo Domain systems had those, and they were great.
Set SYSTYPE to BSD4 and get the BSD tree and all that came with it, or
SYSV to get the other stuff.

Would indeed work great for things like /bin or even
/usr/local/etc -> /${HOST}/usr/local/etc

I was running a special patch version 2.2 at one time, that had variant
replacement in the lookup-cache routines. But I never was able to figure
out a handy way to get the info back into the kernel. So I gave up. One
would need to get at the user environment of the process, and then parse
and scrutinize the ENV every time you need to use a replacement. So
probably libc is the place to put it, but then you get into trouble
again when somebody uses the not standard libc...

Also got a lot of flack from people suggesting it would create security
problems.... (I beg to differ)

But I would really like the timewarp back to 1985.

--WjW




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