Re: /bin/sh as an alternative
On Fri, 16 Jan 1998, Adrian Bridgett wrote:
> On Fri, Jan 16, 1998 at 10:40:43AM +1100, Hamish Moffatt wrote:
> > On Fri, Jan 16, 1998 at 12:08:47AM +0100, Remco Blaakmeer wrote:
> > > Yes, I can only agree. But is bash actually completely POSIX-compliant
> > > (and nothing more than that) when called as /bin/sh ?
> >
> > It would appear not:
> >
> > sh-2.01$ echo hello {there,world}
> > hello there world
>
> In fact even being called as "sh --posix" it does this. I'm fairly sure that
> there is an option to turn brace expansion off though.
>
> However is this being non-POSIX or merely an extension ontop of POSIX? I
> _like_ brace expansion and would be a bit miffed (to say the least) if it
> got turned off by default. A quick check shows that ksh also does brace
> expansion, but (pd)ksh doesn't.
If a shell says "when called as sh, I am POSIX-compliant", can we file a
bug to any non-POSIX feature it has when called as sh? Scripts that use sh
might depend on brace expansion not to happen.
> The original policy was more "your scripts shouldn't use non-POSIX features
> if they are run using /bin/sh" than anything else.
Yes, but policies can be adapted. The above line should remain in the
policy, of course.
> I can't check with the original post, but personally I think that if a
> script *does* use bash features then in addition to beginning "#!/bin/bash"
> it should Depend: on bash. Eventually we could just have a POSIX compliant
> shell in /bin and stop requiring bash (obviously this is a long term goal).
No, packages shouldn't depend on essential packages. Almost every package
needs bash for scripts etc. (even if it is only for {pre,post}{rm,inst}).
Remco
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