Re: [PATCH v2] mk: filter duplicate configuration entries

[Christian Ehrhardt <christian.ehrhardt@canonical.com>]

Hi,
I came up with something very similar when looking for tac replacements
yesterday, but had no time to finish things.
But your suggestion is even shorter - I had found "sed -n '1{h;T;};G;h;$p;'
file" or "sed -n '1!G;h;$p'".
That removes the tac dependency, which I agree is a good thing.

To chain things up without a temp file one would need the "in-place"
features of sed&awk which I'm not sure they are available (awk >=4.1 and
only GNU awk).
sed -i is only used in validate-abi.sh which might not be used on all
platforms to count as "-i is there already so I can use it".
And I really don't want to break anyone due to that change, just naively
clean up the resulting config a bit.
Also we already have a temp file .config_tmp in the same scope and remove
it on our own.
So it is not that much different to create and remove a second one for that
section.

Thanks for both of your feedback, submitting v3 now ...


Christian Ehrhardt
Software Engineer, Ubuntu Server
Canonical Ltd

On Tue, Jul 5, 2016 at 9:47 PM, Thomas Monjalon <thomas.monjalon@6wind.com>
wrote:

> 2016-07-05 17:47, Ferruh Yigit:
> > On 6/30/2016 1:00 PM, Christian Ehrhardt wrote:
> > > +           tac $(RTE_OUTPUT)/.config_tmp >
> $(RTE_OUTPUT)/.config_tmp_reverse ; \
> > Now we are adding new binary dependency (tac) to build system
>
> tac can be replaced by sed '1!G;h;$!d'
>
>