Subject: Re: [PATCH 7/8] Makefile: stop having command-list.h depend on a wildcard

From: Junio C Hamano <[email-masked]>
Date: Thu, 21 Oct 2021 11:24:33 -0700

Jeff King <[email-masked]> writes:

> On Wed, Oct 20, 2021 at 08:39:58PM +0200, Ævar Arnfjörð Bjarmason wrote:
>
>>  get_synopsis () {
>> +	head -n 10 "Documentation/$1.txt" |
>>  	sed -n '
>>  		/^NAME/,/'"$1"'/H
>>  		${
>>  			x
>>  			s/.*'"$1"' - \(.*\)/N_("\1")/
>>  			p
>> -		}' "Documentation/$1.txt"
>> +		}'
>>  }
>
> By the way, I'm not sure about the utility of this change. It reduces
> the number of lines that sed looks at, but at the cost of an extra
> process. That's probably a net loss. And if we did want to limit the
> data sed covers, doing "pq" after we matched would be simpler.

Doesn't the above

 - slurp the lines into hold space while we are in the synopsis
   part;
 - otherwise keep reading and discarding;
 - and do the processing at end

So presumably, instead of waiting till the end, can't we immediately
process the thing and exit?

I guess your "'pq' after we matched" is saying the same thing.  I
agree that extra process with an ad-hoc limitation of 10 does leave
a bad taste in my mouth.