2006-08-27, 15:29(+02), Michal Nazarewicz:
> Stephane CHAZELAS <this.address@is.invalid> writes:
>
>> Neither ash, bash or zsh are the Bourne shell. [...] You can find
>> a Bourne shell as the /bin/sh of Solaris [...]
>
> You're right; I've checked that on SunOS 5.10 and it've printed 0.
>
>> The Bourne shell doesn't have $((...)), and there's no standard
>> specifying the Bourne shell.
>
> I get more and more confused as far as standards are concerned. Some
> time ago I've downloaded "The Open Group Base Specifications Issue 6
> IEEE Std 1003.1, 2004 Edition" and checked all my scripts whether the
> conform to that standard and now it appears they will all crush and
> burn on some unix platforms.
[...]

Those standards specify the POSIX sh which is based on a subset
of ksh which is itself based on the Bourne shell.

sh over the time was a Thomson shell, then a Bourne shell, then
a POSIX shell. Where before they were implementations, now it is
a standard, and several sh implementations (bash, ksh, new
ashes...) implement that standard.

--
Stéphane