tip shell escape (4.3BSD)

[Dan Lanciani]

In article <600 at varian.UUCP>, david at varian.UUCP (David Brown) writes:
> I've been having problems using tip on 4.3BSD.  When I try to use any
> tilde command that requires forking a shell (~!, ~$, etc.), I get:
> 
> 	/bin/csh: permission denied
> 
	This is a "feature" of the C-shell.  If on interactive startup
it finds that its real uid != its effective uid or its real gid !=
its effective gid it prints this unhelpful message and exits.  I assume
this is supposed to prevent evil hackers from getting privileged shells.
Of course, all evil hackers use sh so nothing is gained by the hack.
It would make much more sense to fix the program (tip in this case) than
to break the shell.  Note that this also makes setuid C-shell scripts
fail.

					Dan Lanciani
					ddl at harvard.*