Greg A. Woods said:

>No, not on any AT&T UNIX System V Release 4.0 or newer (or SunOS-5.x).
>
>Those systems all support setgroups(2) and so far as I've ever seen the
>login program on all derrivatives of those systems always calls
>setgroups() when you login making your session have the privileges of
>all the groups you are a member of at that time (up to the maximum
>number allowed by the kernel, NGROUPS_MAX, of course).

That's not what I see here on my network on Solaris 2.6 and Solaris 8.

rattler> id -a
uid=1001(rmk) gid=10(staff) groups=10(staff),777(foo)
rattler> ls -l hello
-rw-r-x---   1 root      foo         5924 Apr 26 16:53 hello
rattler> ./hello
ksh: ./hello: cannot execute
rattler> /usr/bin/newgrp foo
$ id -a
uid=1001(rmk) gid=777(foo) groups=10(staff),777(foo)
$ ./hello
hello,world

Also, ksh and sh have their own wierd builtin newgrp.
-- 
Rick Kelly  rmk@rmkhome.com  www.rmkhome.com