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From: Hartmut Goebel <h.goebel@crazy-compilers.com>
To: guix-devel@gnu.org
Subject: Re: avoid wrapper scripts when possible
Date: Sun, 5 Nov 2017 12:10:42 +0100	[thread overview]
Message-ID: <d9f23885-e113-47e8-34a2-0b8457127acf@crazy-compilers.com> (raw)
In-Reply-To: <8760argizk.fsf@elephly.net>

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Hi,

Ricado proposed a new and better solution already. Nevertheless I want
to comment on this proposal, sint it includes a pitfall and would not work:

Am 03.11.2017 um 22:17 schrieb Ricardo Wurmus:
> exec /home/rekado/.guix-profile/bin/python <(/run/current-system/profile/bin/tail -n +4 "$0")
[...]
> This seems to work just fine and off the top of my head I can’t think of
> a situation where this would fail — unless the wrapped script performed
> the same kind of trick of reading its contents through $0.  (How likely
> is that?)

Indeed for Python programs it is quite common to revert to the filename
using the variable "__file__". And if feeding in the script from stdin
would set __file__ to "<stdin>". Using __file__ is more often used in
package modules than in scripts (which could use $0 (sys.argv[0]).
Anyway this is a pitfall we should avoid.

Please not that Ricardo's new solution, based on guile and execl does
not suffer from this problem (I verified).

-- 
Regards
Hartmut Goebel

| Hartmut Goebel          | h.goebel@crazy-compilers.com               |
| www.crazy-compilers.com | compilers which you thought are impossible |


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  parent reply	other threads:[~2017-11-05 11:10 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-11-02 21:31 avoid wrapper scripts when possible Ricardo Wurmus
2017-11-03 18:54 ` Christopher Baines
2017-11-03 19:22   ` Jan Nieuwenhuizen
2017-11-03 21:17   ` Ricardo Wurmus
     [not found]     ` <874lqbghlz.fsf@elephly.net>
2017-11-03 22:41       ` Ricardo Wurmus
2017-11-05 11:10     ` Hartmut Goebel [this message]
2017-11-04 21:42   ` Eric Bavier
2017-11-04 10:12 ` Hartmut Goebel
     [not found]   ` <87tvy9ptge.fsf@elephly.net>
2017-11-05 11:00     ` Hartmut Goebel
2017-11-05 17:06       ` Ludovic Courtès
2017-11-06 15:53 ` Dave Love
  -- strict thread matches above, loose matches on Subject: below --
2021-09-07 18:52 Attila Lendvai
2021-09-07 20:41 ` Maxime Devos
2021-09-08  9:20   ` Attila Lendvai
2021-09-08 10:39     ` Maxime Devos
2021-09-24 21:38 John Kehayias

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