From owner-freebsd-questions@FreeBSD.ORG  Tue Feb 12 16:10:46 2013
Return-Path: <owner-freebsd-questions@FreeBSD.ORG>
Delivered-To: freebsd-questions@freebsd.org
Received: from mx1.freebsd.org (mx1.FreeBSD.org [8.8.178.115])
 by hub.freebsd.org (Postfix) with ESMTP id 8F43D9FD
 for <freebsd-questions@freebsd.org>; Tue, 12 Feb 2013 16:10:46 +0000 (UTC)
 (envelope-from freebsd-listen@fabiankeil.de)
Received: from smtprelay04.ispgateway.de (smtprelay04.ispgateway.de
 [80.67.18.16]) by mx1.freebsd.org (Postfix) with ESMTP id 34C34EBA
 for <freebsd-questions@freebsd.org>; Tue, 12 Feb 2013 16:10:45 +0000 (UTC)
Received: from [78.35.129.207] (helo=fabiankeil.de)
 by smtprelay04.ispgateway.de with esmtpsa (SSLv3:AES128-SHA:128)
 (Exim 4.68) (envelope-from <freebsd-listen@fabiankeil.de>)
 id 1U5IQ1-0007RW-ON; Tue, 12 Feb 2013 17:09:17 +0100
Date: Tue, 12 Feb 2013 17:06:54 +0100
From: Fabian Keil <freebsd-listen@fabiankeil.de>
To: Devin Teske <Devin.Teske@fisglobal.com>
Subject: Re: Was I Sourced?
Message-ID: <20130212170654.6a649d2c@fabiankeil.de>
In-Reply-To: <13CA24D6AB415D428143D44749F57D7201EA755A@ltcfiswmsgmb21>
References: <511A5771.9020208@tundraware.com>
 <13CA24D6AB415D428143D44749F57D7201EA755A@ltcfiswmsgmb21>
Mime-Version: 1.0
Content-Type: multipart/signed; micalg=PGP-SHA1;
 boundary="Sig_/KZrwQe_Fu5D+npVn4AdUVaS"; protocol="application/pgp-signature"
X-Df-Sender: Nzc1MDY3
Cc: Tim Daneliuk <tundra@tundraware.com>,
 FreeBSD Mailing List <freebsd-questions@freebsd.org>
X-BeenThere: freebsd-questions@freebsd.org
X-Mailman-Version: 2.1.14
Precedence: list
List-Id: User questions <freebsd-questions.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/options/freebsd-questions>, 
 <mailto:freebsd-questions-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-questions>
List-Post: <mailto:freebsd-questions@freebsd.org>
List-Help: <mailto:freebsd-questions-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-questions>, 
 <mailto:freebsd-questions-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Tue, 12 Feb 2013 16:10:46 -0000

--Sig_/KZrwQe_Fu5D+npVn4AdUVaS
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: quoted-printable

"Teske, Devin" <Devin.Teske@fisglobal.com> wrote:

> On Tue, 12 Feb 2013, Tim Daneliuk wrote:
>=20
> > Is there a way for script to determine whether is was sourced
> > or forked off as a subprocess when it was invoked?
> >=20
>=20
> Not that I'm aware of.

sysutils/zogftw, which has to find and parse itself to
generate the verbose help, does the following:

    zogftw_location=3D"$0"

    if [ "zogftw" !=3D $(basename "${zogftw_location}") ]; then
        # Looks like zogftw has been sourced.
        # Try to get the zogftw location through the PATH.
        zogftw_location=3D"$(which zogftw)"
    fi

The check is expected to fail if the user renamed the shell to
zogftw, or the script to something else, but that's unlikely to
happen by accident and the functionality is not essential anyway.

A more reliable method might be investigating $$ and its parents
with ps and friends, but it would also require a lot more code.

I don't remember ever having never seen a ps-based check in the
real world and my impression is that looking at $0 is "best practice"
if the check doesn't have to be perfect.

Fabian

--Sig_/KZrwQe_Fu5D+npVn4AdUVaS
Content-Type: application/pgp-signature; name=signature.asc
Content-Disposition: attachment; filename=signature.asc

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.19 (FreeBSD)

iEYEARECAAYFAlEaaKYACgkQBYqIVf93VJ0d8QCgifpZzsb069VgZ6dSLdiYO6d4
XjYAn05BhTQMJ/3x3+rLePwNpM4/Z4J3
=fHzq
-----END PGP SIGNATURE-----

--Sig_/KZrwQe_Fu5D+npVn4AdUVaS--