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Hi.
Arthur Krewat <krewat(a)kilonet.net>:
There's also the setgid bit on directories,
that when files are created,
they will be in the group that the parent directory has on it.
IIRC this was a Sun
invention. It was in SunOS 4.x, and may even have
been in SunOS 3.x.
Also, I don't think it's been
mentioned, but there's the setuid bit on
directories - otherwise known as the sticky bit. When set, even if you
have rights to "write" the directory (meaning, delete files), you can't
delete those owned by other users. Useful for /tmp
Also a SunOS invention, IIRC.
I have no idea what the timeline is for either of
these features :)
Timeline is late 80s, SunOS 4.0, I believe. (Larry? :-)
These ideas later propogated into SVR4 / Solaris, Linux and most (if not all)
the other proprietary Unixes.
Makes a lot of sense. I just fired up my Consensys SVR4.2 VirtualBox
guest, and sure enough, neither the sticky bit, nor setgid work on
directories.
My first commercial experience with UNIX as a consultant was SunOS. I
had worked on Version 6 earlier, but that was purely personal and never
more than messing around with a uVAX a friend had brought home from work.
thanks for the info!
art k.