[SUGGESTION] Some lfs functionality in os library, please!

[Dirk Laurie <dirk.laurie@...>]

Every time I require lfs, I ask myself: why is this stuff not in the
os library?

I understand that not all systems support everything that lfs
has. And that Lua is very platform-independent.

But the goal of platform-independence does not stop Lua
from offering os.execute, which invites the user to write
platform-dependent code, and io.popen, which "is system
dependent and is not available on all platforms".

The absence of functions so basic that even CP/M and PC-DOS
had them is the one thing that stops Lua from breaking into
the Perl/Python cartel of scripted system programming.

If all of lfs is too much, here is my order of preference:

1. dir
2. chdir, mkdir, rmdir, currentdir
3. attributes, setmode, touch
4. lock, unlock, lock_dir
5. link, symlinkattributes