From owner-freebsd-questions@FreeBSD.ORG Fri Oct 10 15:38:07 2014 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 03F261A0 for ; Fri, 10 Oct 2014 15:38:07 +0000 (UTC) Received: from cosmo.uchicago.edu (cosmo.uchicago.edu [128.135.52.97]) by mx1.freebsd.org (Postfix) with ESMTP id D0F94A3E for ; Fri, 10 Oct 2014 15:38:06 +0000 (UTC) Received: by cosmo.uchicago.edu (Postfix, from userid 48) id B9ACBCB8C9C; Fri, 10 Oct 2014 10:38:05 -0500 (CDT) Received: from 128.135.70.212 (SquirrelMail authenticated user valeri) by cosmo.uchicago.edu with HTTP; Fri, 10 Oct 2014 10:38:05 -0500 (CDT) Message-ID: <61956.128.135.70.212.1412955485.squirrel@cosmo.uchicago.edu> In-Reply-To: References: <5437FB8B.9080008@hiwaay.net> Date: Fri, 10 Oct 2014 10:38:05 -0500 (CDT) Subject: Re: sh man page .... From: "Valeri Galtsev" To: "Michael Sierchio" Reply-To: galtsev@kicp.uchicago.edu User-Agent: SquirrelMail/1.4.8-5.el5.centos.7 MIME-Version: 1.0 Content-Type: text/plain;charset=iso-8859-1 Content-Transfer-Encoding: 8bit X-Priority: 3 (Normal) Importance: Normal Cc: FreeBSD Questions X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 10 Oct 2014 15:38:07 -0000 On Fri, October 10, 2014 10:30 am, Michael Sierchio wrote: > On Fri, Oct 10, 2014 at 8:30 AM, William A. Mahaffey III > wrote: > >>.....I had a bunch of shell scripts written to use Linux >> sh, which was in fact bash, which means it had a superset of the >> arithmetic >> operators that traditional sh had. When I use these scripts under sh >> under >> FBSD 9.3, they largely work, though there are some minor differences >> (empty >> strings evaluate to zero (0) under bash, error under sh). The man page >> for >> sh doesn't reflect some of these compatibilities/incompatibilities, > > Nor should it. The Bourne Shell is the Bourne Shell, is adequately > documented by the man page, and warnings about incompatibility are the > responsibility of those who foist off bash as sh. > > You're blaming your own bad habit on others. :-) > Let me second it. I recently re-discovered (yes, I knew it since long ago, just forgot) that Linuxes usually have "sh" as a symlink just pointing to bash. It kind of kicked me out of my chair: security wise (and in general) you shouldn't use large code (which bash is) to do just a small set of "features" (which sh is). It just reminded me that Linux started in general as a "hack" and still didn't fully grew out of it... Valeri ++++++++++++++++++++++++++++++++++++++++ Valeri Galtsev Sr System Administrator Department of Astronomy and Astrophysics Kavli Institute for Cosmological Physics University of Chicago Phone: 773-702-4247 ++++++++++++++++++++++++++++++++++++++++