at files and permissions

Brandon S. Allbery allbery at ncoast.ORG
Mon Jul 10 01:42:40 AEST 1989


As quoted from <13809 at ncoast.ORG> by allbery at ncoast.ORG (Brandon S. Allbery):
+---------------
| As quoted from <669 at lzaz.ATT.COM> by hutch at lzaz.ATT.COM (R.HUTCHISON):
| +---------------
| | About "at" requiring "root" permission, I guess it needs it to write
| | into the "atjobs" directory.
| +---------------
| 
| at needs root permissions so it can setuid() itself to the owner of the at
| job file, so it can execute the job as the user who submitted it.
+---------------

Whoops!  Open mouth, insert foot....  ;-) The run-jobs side of "at" needs root
for that -- but the run-jobs side is cron.  "at" needs root permissions to
write to /usr/lib/cron/FIFO and thereby notify cron that something has
changed.  (FIFO is writable only be root, again for security reasons.)

Gotta stop posting news before my first cup of coffee in the morning ;-)

++Brandon
-- 
Brandon S. Allbery, moderator of comp.sources.misc	     allbery at ncoast.org
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