what is the 'l' permission?

[Jon Zeeff]

> >>-r-Sr-lr--   1 root     other        865 Nov 18 09:45 595918800.a
> >>
> >According to the AT&T 3B4000 & 3B15 Computer UNIX System V User's and
> >System Administrator's Reference Manual Section 1 (305-205),
> >the l in the group execution slot means that mandatory locking will
> >occur during access.

Can someone explain "mandatory locking" as used here.  I find that Sys V.3
allows two processes to open and write to a file with 'l' permisssions.






-- 
Jon Zeeff      		  		A month ago I modified broke into
umix!b-tech!zeeff		        your system and modified your kernel.
zeeff at b-tech.ann-arbor.mi.us		Have you proved me wrong?