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Re: [PLUG] Shell scripting?
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On Wed, 21 Apr 2010, Randall A Sindlinger wrote:
> On Wed, Apr 21, 2010 at 09:49:12AM -0400, Paul L. Snyder wrote:
> >
> > Invoking bash as sh (that is, via the link) changes its behavior.
> > (It's the equivalent of invoking with the --posix option.) It doesn't
> > result in a perfect emulation of the historical Bourne shell behavior,
> > but it shifts a few things around so it's a bit closer.
> I never read the "INVOCATION" section of the bash man page before.
> I had no idea. I can imagine an interview question now of "when
> is a symlink not just a symlink". :-P
That is the design philosophy behind busybox...mash a bunch of utilities
into a single executable that changes its behavior depending on the name
by which it is invoked.
If you're writing a shell script and want to try something like this
yourself, the name the script was invoked under is stored in the $0
variable.
> After reading that section, either I'm misunderstanding it, or there's
> actually an even yet more subtle difference to invoking bash as /bin/sh
> vs invoking it with --posix.
You're right, my memory was fuzzy. It also changes some other start-up
behaviors. I'll leave the gory details to JP. ;)
Paul
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