POSIX bashing

Doug Gwyn gwyn at smoke.brl.mil
Mon Mar 11 08:42:09 AEST 1991


In article <3419 at unisoft.UUCP> greywolf at unisoft.UUCP (The Grey Wolf) writes:
>I think that POSIX is an attempt at an implementation of a bare-bones OS.
>There are too many things there which are simply done wrong.

POSIX is not an implementation of anything; it's a set of standards
that allow people to specify certain minimal levels of functionality
when they purchase computer systems.  In particular, IEEE Std 1003.1
conformance guarantees that programs written to not step beyond the
bounds of what is specified by that standard will operate correctly
in a wide variety of different (POSIX-compliant) environments.

I'm not aware of very many real problems with IEEE Std 1003.1.

>Of course, one could argue that a standard should not try to define too
>much...but I think POSIX purposely decided to look more like System V and
>ignore all the interesting bits that made BSD better.  Why, I'm not sure.

As a member of the original P1003 working group, I can tell you that
the 1984 /usr/group Standard, minus the portion adopted by X3J11,
formed the starting point for Std 1003.1.  It is fairly obvious why
an organization of commmercial UNIX users and vendors (/usr/group)
would have followed UNIX System V more closely than 4BSD.  In the
course of preparing Std 1003.1, P1003 was careful to consider BSD
features as well as System V features, among other possibilities.
The final standard was not an exact match to ANY existing system,
but it did specify a fairly high level of functionality that could
be met with relative ease by commercial vendors.

>It's truly a pity that System V has more marketing clout; BSD is just SO
>much more usable.

In my opinion, having used both systems extensively, a raw UNIX
System V Release 2 environment and a raw 4.3BSD environment are
both not up to my personal standards of usability, although in
different ways.  Combined environments are better, and enhanced
shell features and nice bitmapped terminal features help too.
At the programming interface level, which is what Std 1003.1 was
addressing, the System V terminal handler interface (which in a
modified form was adopted by 1003.1) is much better than 4.3BSD's,
while other 4BSD features are being adopted in extensions to 1003.1.



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