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Date:	Mon, 14 Jun 1999 09:23:54 -0400
From:	Elliott Hughes <Elliott.Hughes@genedata.com>
Message-Id: <199906141323.PAA1469399@relay.ch.genedata.com>
To:	Elliott Hughes <Elliott.Hughes@genedata.com>,
	Tim Goodwin <tjg@star.le.ac.uk>
Subject: Re: backgrounded jobs
Cc:	rc@hawkwind.utcs.toronto.edu

> Does this suffice?
> fn prompt {if(!~ $apid $lastapid){echo kill $apid;lastapid=$apid}}

i suppose so. it's a bit uglier, because rc automatically outputs the
pid, but i can live with it.

> I didn't really give much thought to this; just left the "bug" in the
> man page.  But doesn't this function come close? ...

that's nasty, though, when the builtin requires so little alteration.
here's a snippet from my local rc:

/* drop first n (default 1) items of variable xs (default $*) */

static void b_shift(char **av)
{
	int n = (av[1] == 0 ? 1 : a2u(av[1]));
	List *xs, *dollarzero;

	if (av[1] != 0 && av[2] != 0 && av[3] != 0) {
		arg_count("shift");
		return;
	}
	if (n < 0) {
		badnum(av[1]);
		return;
	}
	if (av[1] == 0 || av[2] == 0) {
		xs = varlookup("*")->n;
		dollarzero = varlookup("0");
	} else {
		xs = varlookup(av[2]);
	}
	
	while (xs != 0 && n != 0) {
		xs = xs->n;
		--n;
	}
	
	if (av[1] == 0 || av[2] == 0) {
		varassign("*", append(dollarzero, xs), FALSE);
	} else {
		varassign(av[2], xs, FALSE);
	}
	set(TRUE);
}

note that i don't consider dropping items from an empty list to
be an error, in contrast to Byron's rc. i don't know why he chose
to make it behave like that (Duff's doesn't, and neither do any
functional programming languages I can think of).

	-e

-- 
"Act Swiss. Be Global." -- ABB Werbung, 1999.