X-Recipient: archive-cygwin AT delorie DOT com
DomainKey-Signature: a=rsa-sha1; c=nofws; d=sourceware.org; h=list-id
	:list-unsubscribe:list-subscribe:list-archive:list-post
	:list-help:sender:subject:references:to:reply-to:from:message-id
	:date:mime-version:in-reply-to:content-type
	:content-transfer-encoding; q=dns; s=default; b=Sl/uC7LiXgIllnjI
	P26ddAYUgsgt2Bs8VN9AEBUP9gVBHtV5hOYG3WOvfTc+ORCLsGQZNZQXpn7npVZh
	ZwKORT77K+aVSn1LY4cDw0tna5n/divnXWnqlPaj7rxaZYCtGrJ4I1jI/At+0OfF
	7R5aLYlWz/fnvF4bHBZQ3gOJnTc=
DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=sourceware.org; h=list-id
	:list-unsubscribe:list-subscribe:list-archive:list-post
	:list-help:sender:subject:references:to:reply-to:from:message-id
	:date:mime-version:in-reply-to:content-type
	:content-transfer-encoding; s=default; bh=U0FSa8PK4CSD4V7CqXhlWE
	zcNK8=; b=PujyzR0fz9DQGNSVMpLBBARdE9JBbnfBhgGVvMvFnR19tRvKY+1zXU
	kVzmu2r2KjrIaSpgDh9R0cY72nItmRDecDa/S9hL4BqLFMB+b+9vfLQykOvbiScg
	5ZCAo0XBlSt/Pq8pmzyU+4Ow2qEjGCuj+kOO+GShmu4Kr6s5njycI=
Mailing-List: contact cygwin-help AT cygwin DOT com; run by ezmlm
List-Id: <cygwin.cygwin.com>
List-Subscribe: <mailto:cygwin-subscribe AT cygwin DOT com>
List-Archive: <http://sourceware.org/ml/cygwin/>
List-Post: <mailto:cygwin AT cygwin DOT com>
List-Help: <mailto:cygwin-help AT cygwin DOT com>, <http://sourceware.org/ml/#faqs>
Sender: cygwin-owner AT cygwin DOT com
Mail-Followup-To: cygwin AT cygwin DOT com
Delivered-To: mailing list cygwin AT cygwin DOT com
Authentication-Results: sourceware.org; auth=none
X-Virus-Found: No
X-Spam-SWARE-Status: No, score=-0.1 required=5.0 tests=AWL,BAYES_05,KAM_LAZY_DOMAIN_SECURITY,RCVD_IN_DNSWL_LOW autolearn=no version=3.3.2 spammy=Hx-spam-relays-external:shaw.ca, H*r:shaw.ca, H*RU:shaw.ca, elvis
X-HELO: smtp-out-so.shaw.ca
X-Authority-Analysis: v=2.2 cv=cNuQihWN c=1 sm=1 tr=0 a=WqCeCkldcEjBO3QZneQsCg==:117 a=WqCeCkldcEjBO3QZneQsCg==:17 a=IkcTkHD0fZMA:10 a=xNf9USuDAAAA:8 a=Xq9WkkR8zaALFPDUKGUA:9 a=QEXdDO2ut3YA:10 a=SEwjQc04WA-l_NiBhQ7s:22
Subject: Re: Standard LEX variable doesn't work in Make.
References: <d06883e8208624afb5d094ebd3e78375 AT mail DOT kylheku DOT com> <11448207-52c8-6745-999f-48a4534bbc41 AT t-online DOT de> <eee3ac0a-6715-1517-9045-2e2ac8544c66 AT SystematicSw DOT ab DOT ca> <4805811d-559f-a49d-9b2f-5041a0b94b08 AT t-online DOT de>
To: cygwin AT cygwin DOT com
Reply-To: Brian DOT Inglis AT SystematicSw DOT ab DOT ca
From: Brian Inglis <Brian DOT Inglis AT SystematicSw DOT ab DOT ca>
Message-ID: <8af64289-18cd-d14a-0fea-10e80d2752f8@SystematicSw.ab.ca>
Date: Fri, 25 Nov 2016 20:42:09 -0700
User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.5.0
MIME-Version: 1.0
In-Reply-To: <4805811d-559f-a49d-9b2f-5041a0b94b08@t-online.de>
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Transfer-Encoding: 8bit
X-CMAE-Envelope: MS4wfD5TGEmwprUGlrQwDW73IOOYLLNnPLgaYeOTbroWBtPy7rhfg3PuX0XJOVFi9pAT/aU4mXSJScmniyp35yR7tq41ITxRMLQzWIb3kYVkNxHWkIZnlDct N0QynAtcGwUbN9fBQJoR/2ARcUoswG0L7wK001C3KEYUS0aArKIXsudONN/GgwCMySW7XOtFUmpKIA==
X-IsSubscribed: yes

On 2016-11-25 17:08, Hans-Bernhard Bröker wrote:
> Am 25.11.2016 um 15:31 schrieb Brian Inglis:
>
>> One solution, and the most common in Cygwin, is the package flex should
>> create a symlink lex if no such symlink or exe exists;
>
> In this case I believe that would be less than fully correct, because
> flex is not a clean drop-in replacement for generic lex. For that one
> has to add the '-l' flag. So instead of a symlink one would use a
> wrapper script much like the 'yacc' script found in the 'bison'
> package, i.e.:
>
>     #! /bin/sh
>     exec /usr/bin/flex -l "$@"

On Debian both yacc and bison.yacc are alternatives;

>> or by the FHS,
>> create a group of alternatives, with a slave alternative for each of
>> its public components e.g. bin, man, info, etc. files.
>
> I don't think 'alternatives' is applicable here. We're not looking at
> several packages providing the same file --- we're looking at
>
> * single packages offering the same executable under more than one
> name, causing it to express different personalities, like ex ->
> vi.exe, view -> vi.exe, latex --> pdftex.exe,

and all vi, vim, nvi, elvis etc. links are handled via alternatives:
it's used as the canonical example in

	https://wiki.debian.org/DebianAlternatives
  
> * a subsystem like texlive installing a truckload of executable
> scripts somewhere else, and links from /bin to them.

but tex uses no alternatives.

> So while I agree that the 'alternatives' mechanism could, or even
> should be used more in Cygwin, I don't think this is one of the cases
> where that applies.

Cygwin currently seems to follow the RH/RHEL/Fedora model using it in
limited cases. Not running Cygwin/X I don't know if it is used for X
or Gnome packages, where it is used extensively in Debian-based distros.
One commenter on Debian notes it is also used for: "
- cases where you've got a common name referring to specific name
   (like emacs-->/usr/bin/emacs20)
- cases where an older style name refers to the modern equivalent
   (maybe cc-->/usr/bin/gcc or csh-->/usr/bin/tcsh or rcp-->/usr/bin/scp)
- cases where a Unix-style name refers to the modern GNU equivalent
   (like yacc-->/usr/bin/bison)."
and I'd add it is also used for some versioned .so files and language
variants, so it appears it can apply wherever the packager decides it
should.
Cygport currently supports it for postinstall(/preremove) in the berkdb
cygclass and Google shows some other packages also appear to use it.
Perhaps Cygwin packages should use it more, whenever symlink creation
is considered for some component.

-- 
Take care. Thanks, Brian Inglis, Calgary, Alberta, Canada

--
Problem reports:       http://cygwin.com/problems.html
FAQ:                   http://cygwin.com/faq/
Documentation:         http://cygwin.com/docs.html
Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple