In message <[EMAIL PROTECTED]>, "Paul A. Scott" writes:
>> I think you missed the fine point in the "kick everybody *else*
>> off" comment.
>
>Ahhh. I guess you mean that revoke() would change to do that. You're right,
>I did miss your point.
>
>> The point is you cannot serialize against other processes.
>
>But that's the point of serialization. Anyway, if init is the only process
>opening a tty,

revoke is used in most "login daemons", telnetd, getty and elsewhere.

There is no way you can close the race between:

        revoke("/dev/ttyfoo");
and
        open("/dev/ttyfoo");

Not even in init(8).  There is always the risk that another process
opens the device between the two.

-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
[EMAIL PROTECTED]         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe    
Never attribute to malice what can adequately be explained by incompetence.

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