Bad login user id(sco-unix)

[Eamonn McManus]

halpin at mitisft.Convergent.COM (Chris Halpin) writes:
>The luid is an additional uid associated w/every process that is set at 
>login time and CAN NEVER be changed (changes to the kernel include a new 
>system call - setluid()). ...
>The only way to change your luid under SCO UNIX/Securware
>is to logout and login again.

This is only true if you limit yourself to the official kernel interface.
It's perfectly possible and indeed useful to defeat the stupidity of login
uids by opening /dev/kmem and changing the value there.  We recently
posted a replacement su for SCO Unix that does this.  The same function
could be used in a replacement login or cron.

>The luid also
>creates problems with cron (you need to shutdown to restart cron since it
>needs to be run w/no luid set so that is may run its jobs as any user it 
>chooses).

Another option is to run cron from /etc/inittab, though this is rather
painful to set up.  Since cron forks into the background, you have to have
a dummy process that init is waiting for; you can then kill both the
background cron and this process when you want to restart cron.  It's much
easier to use a replacement cron.
--
Eamonn McManus <em at dce.ie>
Charles Bryant <ch at dce.ie>