guix environment shebang interpreter

guix environment shebang interpreter

[EuAndreh via]

Hi Guix!

Is there a Guix equivalent of the nix-shell shebang?

Sample from Nix documentation
(https://nixos.org/nix/manual/#use-as-a-interpreter):

--8<---------------cut here---------------start------------->8---
#!/usr/bin/env nix-shell
#!nix-shell -i perl -p perl perlPackages.HTMLTokeParserSimple perlPackages.LWP

use HTML::TokeParser::Simple;

...
--8<---------------cut here---------------end--------------->8---

Can I already accomplish this with Guix? If so, how?

I tried searching previous discussions of this topic on Guix mailing
lists, but couldn't find any. If this was disscussed before, could
anyone point me to the thread?

Thanks!

Re: guix environment shebang interpreter

[mlell]

Hi!

> Is there a Guix equivalent of the nix-shell shebang?
> 

You could imagine something like:

     #! /usr/bin/env guix environment --ad-hoc PKG1 PKG2 ... -- 
INTERPRETER


But alas,  on linux you cannot put more than one argument in the shebang 
line.

See this discussion: 
https://unix.stackexchange.com/questions/399690/multiple-arguments-in-shebang

But, one answer there has a possible solution for you: 
https://unix.stackexchange.com/a/399698

--8<-------------------------------------------------------
#!/bin/sh -

if [ "$1" != "--really" ]; then exec bash --posix -- "$0" --really "$@"; 
fi

shift

# Processing continues
----------------------------------------------->8-----------

It lets the script `exec` itself with the right arguments! So maybe put

     exec guix environment --ad-hoc PKG1 PKG2 ... -- INTERPRETER "$0" 
"$@"

there?


Cheers,
Moritz

Re: guix environment shebang interpreter

[John D. Boy]

> > Is there a Guix equivalent of the nix-shell shebang?
> You could imagine something like:
> 
>      #! /usr/bin/env guix environment --ad-hoc PKG1 PKG2 ... -- 
> INTERPRETER
> 
> But alas,  on linux you cannot put more than one argument in the shebang 
> line.

I have successfully gotten this to work by passing -S to env:
#!/usr/bin/env -S guix environment --ad-hoc python python-pandas python-numpy -- python3

See a short test script here: https://gist.github.com/jboynyc/1faa5dc4e278d5b6284795f780d22764

Re: guix environment shebang interpreter

[mlell]

Great!

however, note that at two different time points, you can get different 
versions of python with
this command as the executing machine might have different versions of 
guix.

Only if you pull a specific version of guix (e.g. with guix pull 
--commit) and have it in your PATH
you will get the same packages.

Best regards,
Moritz

---
OpenPGP: 0xB4CCD0677340821E

Am 07.02.2020 00:22 schrieb John D. Boy:
>> > Is there a Guix equivalent of the nix-shell shebang?
>> You could imagine something like:
>> 
>>      #! /usr/bin/env guix environment --ad-hoc PKG1 PKG2 ... --
>> INTERPRETER
>> 
>> But alas,  on linux you cannot put more than one argument in the 
>> shebang
>> line.
> 
> I have successfully gotten this to work by passing -S to env:
> #!/usr/bin/env -S guix environment --ad-hoc python python-pandas
> python-numpy -- python3
> 
> See a short test script here:
> https://gist.github.com/jboynyc/1faa5dc4e278d5b6284795f780d22764

Re: guix environment shebang interpreter

[EuAndreh via]

mlell@posteo.de writes:

> But, one answer there has a possible solution for you:
> https://unix.stackexchange.com/a/399698
>
> --8<-------------------------------------------------------
> #!/bin/sh -
>
> if [ "$1" != "--really" ]; then exec bash --posix -- "$0" --really "$@";
> fi
>
> shift
>
> # Processing continues
> ----------------------------------------------->8-----------
>
> It lets the script `exec` itself with the right arguments! So maybe put
>
>      exec guix environment --ad-hoc PKG1 PKG2 ... -- INTERPRETER "$0"
> "$@"
>
> there?

Hmm, I guess that works. It's a bit ugly but does the job. Thanks for
the link.

I also just wanted to check for the existance of such functionality in
Guix already, before pursuing alternatives.

Thanks Moritz :)