Re: Enhancement to psql command, feedback.

On Wed, May 9, 2018 at 8:17 AM, Ron <ronljohnsonjr(at)gmail(dot)com> wrote:

> On 05/09/2018 02:59 AM, John McKown wrote:
>
> I just wanted to throw this out to the users before I made a complete fool
> of myself by formally requesting it. But I would like what I hope would be
> a minor change (enhancement) to the psql command. If you look on this page,
> https://wiki.postgresql.org/wiki/Shared_Database_Hosting ,
> you will see a number of example which look like:
>
> psql -U postgres template1 -f - << EOT
>
> REVOKE ALL ON DATABASE template1 FROM public;
> REVOKE ALL ON SCHEMA public FROM public;
> GRANT ALL ON SCHEMA public TO postgres;
> CREATE LANGUAGE plpgsql;
>
> EOT
>
>
> To me this looks similar to a UNIX shell script.
>
>
> Because it *is* a Unix shell script. The "<< EOT" is part of a heredoc,
> which is designed to keep everything in one place instead of needing a
> second file for the SQL commands.
>
> https://en.wikipedia.org/wiki/Here_document
>
> (The concept is as old as computing. Anyone who's worked on mainframes or
> proprietary minicomputers from DEC will instantly recognize it.)
>

​Yes, I use HERE docs in my shell scripts. I was just, sort of, wanting to
avoid that by making a "slight" change to the psql program to ignore the
first (and only the first) line of any file referenced​ via a "-f". This is
NOT any kind of critical necessity. I just think it would be "nice" simply
because _I_ have a habit of use the "magic" #! at the start of the first
like in order to have other "languages" (such as python, perl, gawk), be
invoked with the script file name as a parameter. One reason to avoid a
HERE doc is from what I've learned about how BASH at least implements them.
The BASH shell sees the HERE document and copies it into a "temporary" disk
file. It then opens this file and supplies that file descriptor to whatever
is being fed the HERE document as input. So, in effect, using a HERE
document, at least in BASH, does a lot more I/O to the disk system.

Again, this is just a discussion point. And I'm quite willing to admit
defeat if most people don't think that it is worth the effort.

>
>
> --
> Angular momentum makes the world go 'round.
>

--
We all have skeletons in our closet.
Mine are so old, they have osteoporosis.

Maranatha! <><
John McKown