ash documentation

Sven Mascheck mascheck at
Mon May 9 18:11:08 UTC 2011

On Mon, May 09, 2011 at 01:28:17AM +0200, Denys Vlasenko wrote:
> On Saturday 07 May 2011 13:40, Sven Mascheck wrote:

> > Are bash features only added to minimize surprises, that is, to grok
> > existing scripts, and not so much to be used "as documented"?
> I don't understand.
> Bash compat features added to make Linux users' lives easier -
> so that they can use same scripts on "big" Linux installations
> and on "small", busybox-based ones Linux machines.

I guess that's exactly what I meant with "to minimize surprises".

> bash is the de-facto Linux standard shell. I think practicality
> trumps "but it's not a standard feature!!!" zealotry a-la dash.
> Therefore, emulating some bashisms is a good thing.

I'm curious: have you (e.g. by user feedback) already experienced
effects due to ubuntu and debian having moved to dash as /bin/sh?

> for those who don't want to have bash-specific code compiled in,
> CONFIG_ASH_BASH_COMPAT can be unset.

That's a good motivation to return to the source, thanks.
(Do you suggest a certain way to learn the other fixes/features
 or is just following the git log the way to go?)

> > (how to debug subtle problems then?)
> I don't understand.

for the record:
I had wondered about the (unusual?) case where a user
experiences unexpected behaviour (for him) in a script and
has to find out whether he made an error, misunderstood the
language or found a bug.  The reference manual if available
would be the usual start then.


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