On 20 July 2017 at 18:44, Joe Zeff <joe(a)zeff.us> wrote:
On 07/20/2017 02:30 PM, George N. White III wrote:
> On 20 July 2017 at 17:41, Joe Zeff <joe(a)zeff.us <mailto:joe@zeff.us>>
> wrote:
>
> On 07/20/2017 05:31 AM, George N. White III wrote:
>
>
> Rigid adherence to a standard is often overkill. Bashisms have
> been a
> practical problem for systems that use dash for /bin/sh.
>
>
> My understanding is that when bash is invoked as sh, it acts exactly
> as sh itself would, so that only those builtin commands that are in
> sh are available. Judging by what you write, this seems not to be
> the case any more.
>
>
> I don't recall the details, but problem scripts may well have had "#!
> /bin/bash" before the decision
> to use dash.
>
>
If so, the scripts should have been run using bash, not dash. In any
event, if bash is specified, /bin/sh shouldn't ever be invoked.
A policy change required system scripts to use dash. The change was made
to reduce startup time and exposure to bugs in bash. The problems came
because it was not simply a matter of changing :bash" to "dash" -- some
scripts
needed to have bashisms removed.
--
George N. White III <aa056(a)chebucto.ns.ca>
Head of St. Margarets Bay, Nova Scotia