POSIX is finally removing the inane requirement that all of the
standard utilities built into the shell (except for the special
builtin utilities - those are ones like break : set ...) be also
implemented as file system commands.
We have never bothered with that requirement, and have consistently
refused to do so (even though handling it is, and always has been,
relatively trivial - at least on systems supporting #! executable
scripts) as the requirement was so completely useless.
For the built in commands this matters to (cd, umask, ...) this
requirement is now being deleted, the only command that's generally
required to be built in to work fully, which will require a file
system equivalent, is kill(1) which isn't a problem at all (having
that one available to exec can actually be useful, and it has also
always been available that way).
See:
https://austingroupbugs.net/view.php?id=1600
This isn't yet in any draft (not even an unavailable one), but will be.
kre
ps: of course, removing the requirement doesn't preclude systems from
providing any (or all) of the relevant commands as file system (execable)
commands, if they want to.
