[BusyBox] POSIX conformance

[Glenn McGrath]

I just went through SuS to see how busybox fares, we have 48 of 66
required command (not counting shell commands at the bottom)

I think basic POSIX compatability is achievable in the medium to long
term.

We probably have all the commands of the UP (User Portability) option.
(from a quick glance)

There are other options of POSIX conformance that are beyond the scope
of busybox.
i.e.
CD - C Development
FD - Fortran Development
FR - Fortran Runtime
SD - Software Development

Not sure about this one.
BE - Batch Environment

With the exception of those options, we fill out a few commands of XSI
(Extension) conformance.

Some details on basic POSIX conformance.


Required, missing from busybox
==============================
cksum
comm
diff
ed
file
getconf
iconv
join
locale
localdef
lp
mailx
man
nohup
paste
pathchk
pax
pr

Required, at least partially available in busybox
=================================================
(i didnt check supported options or functionality)
ar
awk
basename
bc
cat
chgrp
chmod
chown
cmp
cp
cut
date
dd
dirname
echo
env
expr
find
fold
grep
head
id
ln
logger
logname
ls
mkdir
mkfifo
mv
od
printf
rm
rmdir
sed
sh
sleep
sort
stty
tail
tee
test
touch
tr
tty
uname
uniq
wc
who


They following look ok, probably depends which shell is used.

Shell Commands - Special-Builtin
================================
break
colon (: command)
continue
dot (. command)
eval
exec
exit
export
readonly
return
set
shift
times
trap
unset

Shell Commands - Shouldn't use PATH 
===================================
cd
command
false
fg
getopts
kill
pwd
read
true
umask
wait



Enjoy

Glenn