From owner-freebsd-stable@FreeBSD.ORG Mon Apr 7 00:54:45 2008 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 2C374106564A for ; Mon, 7 Apr 2008 00:54:45 +0000 (UTC) (envelope-from jdc@parodius.com) Received: from mx01.sc1.parodius.com (mx01.sc1.parodius.com [72.20.106.3]) by mx1.freebsd.org (Postfix) with ESMTP id 1FDDC8FC19 for ; Mon, 7 Apr 2008 00:54:45 +0000 (UTC) (envelope-from jdc@parodius.com) Received: by mx01.sc1.parodius.com (Postfix, from userid 1000) id A8B311CC038; Sun, 6 Apr 2008 17:54:44 -0700 (PDT) Date: Sun, 6 Apr 2008 17:54:44 -0700 From: Jeremy Chadwick To: Doug Hardie Message-ID: <20080407005444.GB77472@eos.sc1.parodius.com> References: <1794897B-7A36-412A-8849-87F10268EBAE@lafn.org> <20080406214524.GA72199@eos.sc1.parodius.com> <20080406215237.GA72336@eos.sc1.parodius.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) Cc: freebsd-stable@freebsd.org Subject: Re: getenv in FreeBSD 7 X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 07 Apr 2008 00:54:45 -0000 On Sun, Apr 06, 2008 at 03:05:18PM -0700, Doug Hardie wrote: > > On Apr 6, 2008, at 14:52, Jeremy Chadwick wrote: >> On Sun, Apr 06, 2008 at 02:45:24PM -0700, Jeremy Chadwick wrote: >>> On Sun, Apr 06, 2008 at 02:37:06PM -0700, Doug Hardie wrote: >>>> Somewhere between FreeBSD 6.2 and 7.0 getenv has been changed to return >>>> a >>>> null if an environment variable is set but has no value. I don't find >>>> anything anywhere in the documentation/man pages on this. As a result, >>>> you >>>> cannot distinguish between a variable that is not set and one that is >>>> set >>>> to a value of "". Is this a bug or a feature change? >>> >>> I'd begin peeking here: >>> >>> http://www.freebsd.org/cgi/cvsweb.cgi/src/lib/libc/stdlib/getenv.c >> >> Follow-up: the manpages between 6.3-PRERELEASE and 7.0-STABLE do >> document said change: >> >> http://www.freebsd.org/cgi/man.cgi?query=getenv&apropos=0&sektion=3&manpath=FreeBSD+6.3-RELEASE&format=html > > Says that if the environment variable is NOT IN THE ENVIRONMENT then null > is returned. Setting the variable to "" does put it in the environment. > env returns it properly. > >> >> >> http://www.freebsd.org/cgi/man.cgi?query=getenv&apropos=0&sektion=3&manpath=FreeBSD+7.0-stable&format=html > > Same thing. I find nothing documented about this change. I'm not sure where you're going with this. I see it clearly in the ERRORS section. But besides that, just like Bakul Shah, I cannot reproduce this problem: $ uname -mr 7.0-STABLE amd64 $ gcc -o z z.c $ ./z getenv(FOO) = (null) $ export FOO=yep $ ./z getenv(FOO) = yep export FOO= $ ./z getenv(FOO) = $ cat z.c #include #include int main(void) { char *e = getenv("FOO"); printf("getenv(FOO) = %s\n", e); return 0; } Finally, why did you take freebsd-stable off this mail conversation? If others have the same question in the future, they're not going to be able to read what partook here. I'm re-adding the list. -- | Jeremy Chadwick jdc at parodius.com | | Parodius Networking http://www.parodius.com/ | | UNIX Systems Administrator Mountain View, CA, USA | | Making life hard for others since 1977. PGP: 4BD6C0CB |