On 12/21/21 11:23 PM, jason-tuhs(a)shalott.net wrote:
As an end user, you would not care.
That tends to explain why I've not personally cared.
As a vendor or distributor, you would care. Anyone
doing an OS or other
software distribution (think the BSDs, of course; but also think Apple
or Microsoft) needs to care. Anyone selling a hardware device with
embedded software (think switches/routers; think IOT devices; think
consumer devices like DVRs; etc) needs to care. GPL (or similar
"virally" licensed) software carries legal implications for anyone
selling or distributing products that contain such software; and this
can be a motivation to use software with less-restrictive license terms.
My limited understanding is that the GPLed parts of the product must be
made available. But I'm not aware that using GPLed parts means that
/everything/ /else/ must also be made available.
Also, I believe /made/ /available/ means that it must be accessible or
provided when asked. Thus it does not mean that the GPLed code needs to
be shipped with the product.
I'm aware of a few random features that are in
ksh93 but not other
shells (random, trivial, example that I saw just today*: "printf
%(FORMAT)T"). That said, my first impulse would have been to say no,
there aren't any meaningful (technical) advantages to ksh over bash --
except that it seems there's still some amount of active development
going on in ksh:
The biggest motivation I had in a previous job was to make sure that my
account's shell was set to a shell that lived on the root file system.
I could easily have that shell test to see if my preferred shell was
available and start or exec it. That way I could still log in if the
file system with my preferred shell was not mounted. As if I needed to
address the underlying issue that was preventing the desired shell from
being accessible. E.g. /usr/bin/bash wasn't available b/c /usr wasn't
automatically mounted at boot.
So I guess, for some people at least, there are indeed
reasons to prefer
it, including (according to users in those github issues) performance.
At my last job I helped administer some systems that didn't have any
shells other than was was in the base OS installation. (We won't talk
On the licensing front, the GPL is an issue for bash;
but zsh is
available as a more modern, fully-featured shell that avoids any GPL
issues. This is why Apple switched the default shell in OSX from bash
to zsh: they wanted to avoid the GPLv3. Previously, they had been
shipping the last GPLv2 version of bash, which was from 2006. According
to this blog, they've been avoiding any GPLv3 code and actively working
to remove even GPLv2 code in OSX for quite a while:
That makes sense.
* bash seems to recognize %(FORMAT)T, but only takes
epoch seconds as an
argument. ksh93 takes anything vaguely date-like. zsh and pdksh don't
recognize it at all.
Thank you for the informative reply Jason.
Grant. . . .
unix || die