Re: Detecting invocation as /bin/sh ?

[Alexandre Ferrieux]

On Monday, September 29, 2014 9:51:45 PM UTC+2, Chet Ramey wrote:
> > 
> > So it seems the order is wrong. As a consequence, and this is confirmed by 
> > experience, the #!/bin/sh prefix behaves as featuristic bash.
> > My suggestion then is to undo that mistake.
> 
> Posix mode was never intended to turn bash into a shell that provides only
> what Posix specifies and nothing more.  It makes bash conform to Posix by
> changing things where the default mode differs from what Posix specifies.
> Posix allows this, and allows extensions, and every shell that claims
> Posix conformance (except perhaps `posh') offers extensions beyond minimal
> Posix features.

Forget about posix mode then: bash -p (privileged) offers a lean-and-mean 
variant which pretty much satisfies anybody needing "just sh". However, there 
is no way to store an option in a symbolic link, so all distributions doing "sh 
-> bash" are bound to perpetuate the danger (of "eval-from-the-env"). So it 
would seem normal for some of them to move away from bash as the default sh.

-Alex