tech-userlevel archive

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Old Index]

Re: Proposal for write(1) addition

> pututxline() runs a setuid program to update utmp if needed, so it is
> transparent to the user.

Well, mostly transparent.  But it could just as easily - and
approximately as transparently - send a packet to a daemon instead;
there's nothing sacred about utmp_update.

> No, ptyfs has nothing to do with utmp, and yes, if you want to use
> ptys properly without requiring root, you need ptyfs.

> You also avoid the scan the ptys code and [...].  I don't see any
> advantages using the old BSD ptys, do you?

One potential major advantage and one potential minor advantage.

The major one is compatability.  Code that Just Works all the way from
when ptys were first invented up to now.  Avoiding the "another system,
another idiosyncratic `you must do *this* dance to make ptys work'"
#ifdef (or equivalent) hell - worse, in this case, because in addition
to code authors having to deal with the different API, the end system's
admin has to get something right too.

Is that worth being mired in the past, shackled to accidents of the
first implementation?  Sometimes it is; sometimes it isn't - this is
why I called it a _potential_ advantage.  The only real problem I see
here is that NetBSD is (apprently) not letting admins make that call
for themselves.  (Providing ptyfs for cases where it's a right answer
is good.  Requiring its use for ptys to work, not so much.)

It's true that NetBSD used to provide no more choice.  But to switch
and _still_ provide no choice is kind of the worst of both worlds: you
lose compatability and you don't gain the flexibility of multiple

> [...] and the exposure of the control node.

This is the minor one.

I'm not convinced losing the ability to expose the master-side device
is a good thing.  (Certainly losing the requirement to expose it is;
it's losing the ability to that I'm not so sure about.)  I have no
specific use case; it just feels like preventing stupid things at the
price of preventing clever things.

/~\ The ASCII                             Mouse
\ / Ribbon Campaign
 X  Against HTML      
/ \ Email!           7D C8 61 52 5D E7 2D 39  4E F1 31 3E E8 B3 27 4B

Home | Main Index | Thread Index | Old Index