> A quick test shows that ksh93's "0" is the status of the "echo a".
>  $ echo `cmp -s /etc/group /etc/group; exit 3` >`echo /dev/tty; exit 2` $?
>  0
>  $ echo `cmp -s /etc/passwd /etc/group; exit 3` >`echo /dev/tty; exit 2` $?
>  1
>  $ echo `if cmp -s /etc/passwd /etc/grope; then exit 3; else exit 4; fi` $?
>  2
> These results are... counterintuitive.

Erm badly broken?  It looks as though 'exit n' isn't setting the result!
> 
> > x=$(echo var >&2) : >/dev/null$(echo redir >&2) $(echo arg >&2)
> 
> All but V7 sh agree:
>  arg
>  var
>  redir

The posix spec says arg, redir, var for normal commands but allows
arg, var, redir for 'special builtins' (which include : but not echo).
> 
> Apparently not... but for
> 
>  $ (exit 2)
>  $ a=a
>  $ echo $?
> 
> all do produce
>  0

That is the behaviour that posix requests.


	David

-- 
David Laight: david@l8s.co.uk