Re: persistant psql feature suggestion

From: "Andrew Dunstan" <andrew(at)dunslane(dot)net>
To: "Matthew T(dot) O'Connor" <matthew(at)zeut(dot)net>, "James Pye" <jwp(at)rhid(dot)com>
Cc: <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: persistant psql feature suggestion
Date: 2003-06-28 21:44:35
Message-ID: 004401c33dbe$78986640$6401a8c0@DUNSLANE
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Another way is to put a little shim between the fifo and psql. Here's one I
quickly whipped up in perl (code stolen shamelessly from the perl man
pages). To run in background, invoke thus
( perl myperlfile myfifo | psql gatabase ) &

The only wrinkle I found was that I had to send the \q twice to make it
quit - I have no idea why.
andrew

------------------------------
use strict;

my $curpos;
my $fifofile = shift || usage();

$|=1;

open(FILE,$fifofile) || die $!;
for (;;)
{
for ($curpos = tell(FILE); $_ = <FILE>; $curpos = tell(FILE))
{
print $_;
}
sleep(1);
seek(FILE, $curpos, 0);
}

sub usage
{
print STDERR "usage: ",$0," fifofile\n";
exit 1;
}

----- Original Message -----
From: "Matthew T. O'Connor" <matthew(at)zeut(dot)net>
To: "James Pye" <jwp(at)rhid(dot)com>
Cc: <pgsql-hackers(at)postgresql(dot)org>
Sent: Friday, June 27, 2003 1:44 PM
Subject: Re: [HACKERS] persistant psql feature suggestion

> On Fri, 2003-06-27 at 03:21, James Pye wrote:
> > Greets,
> >
> > Just a thought for a psql enhancement, afiak, it is not easily possible
for persistent connections to a database in a shell script..
> > The ability for psql to remain in the background reading from stdin and
writing to stdout until explicitly killed. More specifically, so a shell
scriptor can have "persistent" connections to the database by calling psql
once(leaving it in the bg), and redirecting stdio through a
fifo(mkfifo)(sending queries by echo > fifo, and fetching results by cat
fifo).
> > When I have tried this in the past it will read the query, execute it,
and exit when the results are cat'd from the fifo.
>
> Not sure if it's exactly what you are looking for, nor how well it's
> still maintained, but....
>
> I believe there is a took out there called pgbash which is a modified
> version of bash that understands database queries natively. I think
> it's just what you are looking for.
>
> Check out: http://www.psn.co.jp/PostgreSQL/pgbash/index-e.html
>
> Looks like it was updated for 7.3
>
> Matthew
>
>
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