Re: [tlug] Bashing away at Unix

["SL Baur" <steve@example.com>]

On 3/14/08, Nguyen Vu Hung <vuhung16plus+shape@example.com> wrote:
> 2008/3/14, Stephen J. Turnbull <stephen@example.com>:
>  >  Note the "under certain conditions".  For example, if as root you do
>  >
>  >  ln -s /bin/bash ~/sh
>  >  ~/sh
>  >
>  >  I'll bet you bash reads .profile, and you can verify it with strace,
>  >  too.

Yes.  When zsh is invoked as sh, it turns off *all* zsh extensions and
behaves as a conformant POSIX shell.

> It didn't reproduce in CentOS release 5 (Final)

I'm not surprised.  Bash has never cared much for standards compliance
and bash scripts which assume /bin/sh is symlinked to bash have been
the bane of Linux for ages.

Ksh also behaves somewhat differently if invoked as /bin/sh and that is
what I meant when I wrote "under certain conditions".

Truth be told, the reliance of Unix user space on a specific meaning of
/bin/sh is no different than the reliance of Microsoft Windows user space
on a user browser == Internet Explorer.  Although it's somewhat amusing
that they tend to "innovate", badly our best features and copy our worst
mistakes.  As Henry Spencer once wrote, "he who does not undertand
Unix is doomed to reimplement it badly".

-sb