The way I have handled this is I put a icon (application) on every students desktop which they drag the file to. This launches a script that sets the permissions of the file to 755 and then copies it to the drop box folder. It pops up a message box saying the file was copied successfully (visual feedback is nice). Haven't yet experimented with having the script determine which class a student is in and consequently which dropbox subfolder to copy to. Otherwise, the directory permissions is set as James mentioned. which makes it a one-way trip for the students' files. It seems to work ok at present. Sincerely, Dave Hopkins <div>On 3/4/07, James P. Kinney III <<a href="mailto:jkinney@localnetsolutions.com">jkinney@localnetsolutions.com</a> > wrote:<blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">OK. A quick test was done. Make the directory group writeable and set the file mask for that directory to make all files -w- for the group. The teacher can still read and move the files but students can only drop them. They can't copy them or list them. Anything a bunch of kids can dream up, a dedicated bunch of old farts can squash. :) On Sun, 2007-03-04 at 20:59 -0600, Petre Scheie wrote: > It's not as convenient, but perhaps you could give each student her/his > own directory within /home/inbox, with permissions set to 770, and put > the teacher into each student's primary group so the teacher can get to > the files. Give each student's directory the same name as the student's > ID, e.g., bob's directory would be /home/inbox/bob. Modify your script > so that is automatically uses the caller's ID to specify the path to the > directory. This way, only the student and the teacher have access to > that student's work. It would be harder to hunt through all the > directories for the students' work, but you could write a script that > parses through all those directories and moves any files found to one > folder in the teacher's $HOME. Give the teacher an icon to call it with > sudo, call it something like "Gather up handed in assignments". > > HTH > > Petre > > Robert Arkiletian wrote: > > mkdir /home/inbox > > chmod 1773 /home/inbox (Not readable by others and sticky bit > > prevents overwriting) > > > > But if a clever kid happens to know the filename of another kid > > > > cp /home/inbox/filename ~ > > > > unfortunately works. Not good. > > ============================== > > My solution: > > Write a 1 line bashscript /usr/bin/handin > > > > cp -p $1 /home/inbox/ > > > > chgrp teacher /usr/bin/handin > > chmod 2755 /usr/bin/handin (setgid escalate priviliges to teacher group) > > > > now > > > > chgrp teacher /home/inbox > > chmod 1770 /home/inbox > > > > To hand-in a test students go > > handin filename > > > > But it does not work. I get > > > > cp: cannot stat `/home/inbox/filename': Permission denied > > > > Why? Apparently, setgid cannot change the group of the process to one > > which you don't already belong to. So I have to add the teacher group > > to all students, which defeats the purpose. So much for privilege > > escalation of setgid. I even tried using setuid. > > > > [root@server ~]# ls -ld /home/inbox/ > > drwxrwx--T 2 root root 4096 Mar 4 16:02 /home/inbox/ > > [root@server ~]# ls -l /usr/bin/handin > > -rwsr-xr-x 1 root root 79 Mar 3 14:40 /usr/bin/handin > > > > I get the same stat Permission denied error. Any suggestions? > > > > > > _______________________________________________ > K12OSN mailing list > <a href="mailto:K12OSN@redhat.com">K12OSN@redhat.com</a> > <a href="https://www.redhat.com/mailman/listinfo/k12osn">https://www.redhat.com/mailman/listinfo/k12osn</a> > For more info see < <a href="http://www.k12os.org">http://www.k12os.org</a>> -- James P. Kinney III CEO & Director of Engineering Local Net Solutions,LLC 770-493-8244 <a href="http://www.localnetsolutions.com">http://www.localnetsolutions.com </a> GPG ID: 829C6CA7 James P. Kinney III (M.S. Physics) <<a href="mailto:jkinney@localnetsolutions.com">jkinney@localnetsolutions.com</a>> Fingerprint = 3C9E 6366 54FC A3FE BA4D 0659 6190 ADC3 829C 6CA7 _______________________________________________ K12OSN mailing list <a href="mailto:K12OSN@redhat.com">K12OSN@redhat.com</a> <a href="https://www.redhat.com/mailman/listinfo/k12osn">https://www.redhat.com/mailman/listinfo/k12osn </a> For more info see <<a href="http://www.k12os.org">http://www.k12os.org</a>> </blockquote></div>