From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on inbox.vuxu.org X-Spam-Level: X-Spam-Status: No, score=-3.3 required=5.0 tests=DKIM_SIGNED,DKIM_VALID, MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED,UNPARSEABLE_RELAY autolearn=ham autolearn_force=no version=3.4.4 Received: (qmail 15544 invoked from network); 18 May 2021 18:52:17 -0000 Received: from zero.zsh.org (2a02:898:31:0:48:4558:7a:7368) by inbox.vuxu.org with ESMTPUTF8; 18 May 2021 18:52:17 -0000 ARC-Seal: i=1; cv=none; a=rsa-sha256; d=zsh.org; s=rsa-20200801; t=1621363937; b=LnOafH4dFSYpD6NSTaN/eqtn3ddYvYXp5BCMycjTiNPmL8rOZogXnRi+Lw8bwZIbbh+FJtOgzi J0YpAJ+W/R4NQj3rPda80K3kJ6HGvN91Qx6l1gOTIaY4Iy8lYkflR56Jol0HniVugbNAFf8hCh sEOuEAmqsggJUwZeVBQ0+ZWul549lxQA9ST35E2SBDZS8zBfIDbZpRYmxQsme5eEkR2ZwvA8IO M9GhOiwlXRKLBHFG+aWWWXFPahIV6hm9f/BUhgni8xQ4YgqjfrEKJG5Clrd7I28V2fUNJZ6EMr Q4d74YFmwc+hkSXhEyKfp41bunv8qt4IEf+aAraoJ5U+xg==; ARC-Authentication-Results: i=1; zsh.org; iprev=pass (relay10.mail.gandi.net) smtp.remote-ip=217.70.178.230; dmarc=none header.from=chazelas.org; arc=none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed; d=zsh.org; s=rsa-20200801; t=1621363937; bh=wUGS3pMOQ1NXoj4KfaScsX/Ak0CiKJBgIgiZafR1510=; h=List-Archive:List-Owner:List-Post:List-Unsubscribe:List-Subscribe:List-Help: List-Id:Sender:In-Reply-To:Content-Type:MIME-Version:References:Message-ID: Subject:Cc:To:From:Date:DKIM-Signature; b=DMqo3pOu42K3QagjfNUC/tOltCK9TFXM0S5CHwSgJ68CL70nVB8+1jMYc1xkJZJsu+q08xyjgC tqaayp34cb0PN/eYSPNxZ/2Fk98OIWfvSSeUegJ5sgCKeLIWYpVtP5fb4F0WkGMp6cGPnoUYCZ HyhUhl9D1fPeZoN11KjIts884JGf15PfFJDv51ivFJ7WKk+2vbFO/Xq3EGFgWyeePzvNiBtYWT vXH3qfsZMDWV11kBmzneiLYq/CaZQkn3JnzznQbmjX+4OlB8QIkSxYx4I+nvyz25OyuKSKvA59 WepBgzH1XgnTLYOR5pjOdnUmL71vbagq7LcsaytJR/t9rA==; DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=zsh.org; s=rsa-20200801; h=List-Archive:List-Owner:List-Post:List-Unsubscribe: List-Subscribe:List-Help:List-Id:Sender:In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID; bh=NBVNWOwSj3A/wMCDNQOtc3CCo5sSg4rQLTHyJH6a3dk=; b=XE26o/Ji2gnR4cviSmw8Gxka0F ni0PifwO/vYXcLz+vmPy+tkMqGCel7srxo4qzO7DUt4yXJ7/YGigvY4ProOJZON0sb4uMBF2rm7pI zp0nvVlhfODeSZZP2cDsyodRGeGm9SM1AyJNpE9inf1Yw8KSiSMakgtLWVxdTNf5ulcJujrinRw3b sJxbWaY3/hiGPzGycMQTAre8KbQCS47UEIqi4TOXGDhZoz5crlkUkGrqXES/cJl6L3v1FCmylRoU5 8oCrVxcKaFjsyDdDJu5ROw+OCu5RuC2SUw6IgOe2b9kaR5l7DOQOXns2h+tW/baEBjbuShB4czA4g nsj8m+VQ==; Received: from authenticated user by zero.zsh.org with local id 1lj4pF-00017L-Bc; Tue, 18 May 2021 18:52:17 +0000 Authentication-Results: zsh.org; iprev=pass (relay10.mail.gandi.net) smtp.remote-ip=217.70.178.230; dmarc=none header.from=chazelas.org; arc=none Received: from relay10.mail.gandi.net ([217.70.178.230]:36021) by zero.zsh.org with esmtps (TLS1.2:ECDHE-RSA-AES256-GCM-SHA384:256) id 1lj4ng-0000nX-S7; Tue, 18 May 2021 18:50:42 +0000 Received: (Authenticated sender: stephane@chazelas.org) by relay10.mail.gandi.net (Postfix) with ESMTPSA id E940A240002; Tue, 18 May 2021 18:50:39 +0000 (UTC) Date: Tue, 18 May 2021 19:50:39 +0100 From: Stephane Chazelas To: Bart Schaefer Cc: Zsh hackers list Subject: $SHLVL origin (was: $PPID not updated when the PPID changes (parent killed)) Message-ID: <20210518185039.7zo76vofxrn6qqqd@chazelas.org> Mail-Followup-To: Bart Schaefer , Zsh hackers list References: <20210516152418.GA39669@zira.vinc17.org> <20210517202608.GA3255290@zira.vinc17.org> <20210518180601.4q6o3xpeva7uhyjo@chazelas.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Seq: 48886 Archived-At: X-Loop: zsh-workers@zsh.org Errors-To: zsh-workers-owner@zsh.org Precedence: list Precedence: bulk Sender: zsh-workers-request@zsh.org X-no-archive: yes List-Id: List-Help: List-Subscribe: List-Unsubscribe: List-Post: List-Owner: List-Archive: 2021-05-18 11:12:54 -0700, Bart Schaefer: > On Tue, May 18, 2021 at 11:06 AM Stephane Chazelas > wrote: > > > > $SHLVL (a (t)csh thing IIRC, not handled by all shells) > > Bash has it, for sure. [...] I remember looking up the origin of it when we were discussing https://www.zsh.org/mla/workers/2016/msg01574.html It does come from tcsh in the early 80s (see https://groups.google.com/forum/message/raw?msg=net.sources/3eER9GEdo2c/B9G1KGziIx4J for instance). Also supported by bash, ksh93, fish, zsh and yash (implement in startup file as shell code only for interactive instances there), but not much else and not in POSIX. -- Stephane