From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Stefan Monnier Newsgroups: gmane.emacs.devel Subject: Re: proced: ppid of process ID 0 can be 0 Date: Tue, 23 Dec 2008 21:34:56 -0500 Message-ID: References: <18765.19040.568030.246241@tfkp04.physik.uni-erlangen.de> <18765.29820.997276.703222@tfkp04.physik.uni-erlangen.de> <18765.51840.943986.608296@tfkp04.physik.uni-erlangen.de> <87wsdqjzar.fsf@kobe.laptop> NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: ger.gmane.org 1230086116 13079 80.91.229.12 (24 Dec 2008 02:35:16 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Wed, 24 Dec 2008 02:35:16 +0000 (UTC) Cc: lekktu@gmail.com, Eli Zaretskii , Roland.Winkler@physik.uni-erlangen.de, emacs-devel@gnu.org To: Giorgos Keramidas Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Wed Dec 24 03:36:21 2008 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([199.232.76.165]) by lo.gmane.org with esmtp (Exim 4.50) id 1LFJbg-0002te-G8 for ged-emacs-devel@m.gmane.org; Wed, 24 Dec 2008 03:36:20 +0100 Original-Received: from localhost ([127.0.0.1]:35044 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1LFJaT-0003c1-OV for ged-emacs-devel@m.gmane.org; Tue, 23 Dec 2008 21:35:05 -0500 Original-Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1LFJaP-0003bd-2A for emacs-devel@gnu.org; Tue, 23 Dec 2008 21:35:01 -0500 Original-Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1LFJaN-0003az-In for emacs-devel@gnu.org; Tue, 23 Dec 2008 21:35:00 -0500 Original-Received: from [199.232.76.173] (port=39435 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1LFJaN-0003aw-BY for emacs-devel@gnu.org; Tue, 23 Dec 2008 21:34:59 -0500 Original-Received: from ironport2-out.pppoe.ca ([206.248.154.182]:28307 helo=ironport2-out.teksavvy.com) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1LFJaL-000876-QQ; Tue, 23 Dec 2008 21:34:57 -0500 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AsgEABsvUUlFxKfZ/2dsb2JhbACBbLxFWJFjhkKBYg X-IronPort-AV: E=Sophos;i="4.36,274,1228107600"; d="scan'208";a="31438382" Original-Received: from 69-196-167-217.dsl.teksavvy.com (HELO pastel.home) ([69.196.167.217]) by ironport2-out.teksavvy.com with ESMTP; 23 Dec 2008 21:34:56 -0500 Original-Received: by pastel.home (Postfix, from userid 20848) id 5A8B98780; Tue, 23 Dec 2008 21:34:56 -0500 (EST) In-Reply-To: <87wsdqjzar.fsf@kobe.laptop> (Giorgos Keramidas's message of "Wed, 24 Dec 2008 00:34:52 +0200") User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.0.60 (gnu/linux) X-detected-operating-system: by monty-python.gnu.org: Genre and OS details not recognized. X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Original-Sender: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.devel:107260 Archived-At: >>>> More to the point: even if we could distinguish the "no ppid" from >>>> "unkown ppid", it's unclear how Elisp code could make use of it. >>> Lisp code cannot, but a primitive written in C can. >> >> Like what can it do? > It can differentiate between FreeBSD 4.3 and FreeBSD 7.2 if they use a > different style of `process root', or between Linux 1.2.X, 2.4.X and > 2.6.X. Right now, Emacs sets `system-type' to "berkeley-unix" on more > than one BSD system. They might be easier to detect at C level. That's not what I'm asking. I'm asking: what can C code (or Elisp code for that matter) do when the ppid is somehow not found (i.e. there's no ppid available, but the process might have a parent). Stefan