proper way to determine arch of *installed* OS, not processor?

[Oliver Grawert]

hi,
Am Freitag, den 06.05.2011, 11:14 -0400 schrieb Robert P. J. Day:
> what is the proper incantation to determine the word size of the
> installed OS?  that is, if i've installed the 32-bit version of ubuntu
> on a 64-bit system, i want to know that the OS is 32 bits, even as the
> processor is 64 bits.  i'm sure it's some option of "uname", but i
> don't have such a system lying around to test it.  thanks.
if its a dpkg based system and you really care about OS and not HW, why
not use:

dpkg --print-architecture

32bit will print i386
64bit will show amd64

ciao
	oli