On 21/11/18 at 19:04, Rowland Penny wrote:
> On Wed, 21 Nov 2018 18:50:42 +0100
> Alessandro Selli <alessandroselli@???> wrote:
>
>> On 21/11/18 at 18:39, Rowland Penny wrote:
>>> On Wed, 21 Nov 2018 18:25:02 +0100
>>> Alessandro Selli <alessandroselli@???> wrote:
>>>
>>>> On 21/11/18 at 18:15, m712 wrote:
>>>>>>   Of course we are, why don't you read before replying?
>>>>> I can't be sure if you are in jest.
>>>>    Of course I am not.
>>>>
>>>>   Dr. Nikolaus Klepp asked:
>>>>
>>>>
>>>> From: "Dr. Nikolaus Klepp" <dr.klepp@???>
>>>> To: dng@???
>>>> Date: Wed, 21 Nov 2018 17:22:00 +0100
>>>> Message-Id: <201811211722.00535.dr.klepp@???>
>>>>
>>>>     
>>>> Why would anybody hardcode the link to sed in the first place?
>>>> Isn't that what $PATH is all about?
>>>>
>>>>
>>>>

>>>>    And I answered with a case where the absolute placement of the
>>>> sed executable does matter and cannot be circumvented with a PATH
>>>> setting or the use of commands like which or command.

>>>>
>>>>
>>>> What is not clear?
>>>>
>>>>
>>>>
>>> You got the context wrong, or as we say here in the UK, you got the
>>> wrong end of the stick ;-)
>>>
>>> He asked 'Why would anybody hardcode the link', what has this to do
>>> with a shebang ?
>>
>>   A shebang is an often used construct that would be broken were not a
>> link in place.
>>
>>   Do you need a drawing to see why?
>>
>>
>>> You are quite correct, you cannot replace a shebang with 'which',
>>> but then, this was never the problem.
>>
>>   Yes, it is.  Because shebangs do require a link from /usr/bin
>> to /bin were files moved from /bin to /usr/bin.
>>
>>
>>> Did you read the debian bugreport ?
>>
>>   Yes, I did.
>>
>>   Now you, how would you have a #!/bin/Rscript script work without a
>> filesystem-level link?
>>
>>
> I repeat, the problem in the bugreport had nothing to do with a shebang,


  The bug report is about Rscript.  Do you know what that is for?

  It's long being considered good practice on updates letting the system
be changed in such a way as to let the old scripts work without
modifications.  That was a golden rule under Solaris for instance, which
explains why they put in /bin and /usr/bin old, non POSIX compliant
versions of shells, sed, awk and so forth, with the revised, improved,
X/Open standard utilities installed in /usr/xpg4/bin/.  Debian broke
this golden Unix rule, putting the link on the filesystem from /usr/bin
to /bin is the correct VUA remedy to the issue they introduced, because
it shifts the responsibility in maintaining the system integrity on
updated to the distribution development team, not on users.

  You're free to disagree of course, but please let me kow if and where
are ever you going to take responsibility in maintaining a GNU/Linux
distribution or a major package.  Or maybe you're going to be a systemd
developer, in which case it would be quite all right and actually pretty
appropriate.



--
Alessandro Selli <alessandroselli@???>
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