sticky bit obsolete?

[Guy Harris]

> To add some incentive for a discussion here, the most recent
> System V Interface Definition, Issue 2 (the two-volme set),
> (Bob hasn't seen this, by the way) has a change for the definition of
> access permission bits for a file.  For CHMOD(BA_OS) (chmod system call):
>   "Issue 1 identified the access permission bit 01000 as "save text
>   image after execution"; Issue 2 indicates it as "reserved"".
> Everywhere else I've seen they have changed every description of the
> permission bit 01000 to "reserved".
> I think this means that a conforming implementation CAN'T use that
> access bit to mean anything -- does anyone have a different interpretation?

Yes.  I interpret it as meaning conforming systems need not use this to mean
"save text image after execution", if for example they don't have such a
concept.  If conforming systems can't use that bit to mean anything, no
conforming systems exist; I sincerely doubt that AT&T-IS wants to be in the
position that the OS of their machines doesn't conform to the SVID....
Applications written based on the specifications of the SVID should not use
this bit, as its meaning is implementation-dependent.
-- 
	Guy Harris
	{ihnp4, decvax, seismo, decwrl, ...}!sun!guy
	guy at sun.com (or guy at sun.arpa)