Re: Add PostgreSQL home page to --help output

> On 12 Feb 2020, at 11:54, Peter Eisentraut <peter.eisentraut@2ndquadrant.com> wrote:
>
> On 2020-02-11 10:34, Daniel Gustafsson wrote:
>> Pardon my weak autoconf-skills, what does the inverted brackets (]foo[ as
>> opposed to [foo]) do in the below?
>> -Please also contact<pgsql-bugs@lists.postgresql.org>  to see about
>> +Please also contact <]AC_PACKAGE_BUGREPORT[> to see about
>
> AC_PACKAGE_BUGREPORT is an Autoconf macro, set up by AC_INIT.  The call above is in the context of
>
> AC_MSG_ERROR([[ ... text ... ]])
>
> The brackets are quote characters that prevent accidentally expanding a token in the text as a macro.  So in order to
getAC_PACKAGE_BUGREPORT expanded, we need to undo one level of quoting. 
>
> See also
<https://www.gnu.org/savannah-checkouts/gnu/autoconf/manual/autoconf-2.69/html_node/M4-Quotation.html#M4-Quotation>for
moreinformation. 

Aha, that's what I was looking for in the docs but didn't find.  Thanks for
sharing!

cheers ./daniel