Re: guile scheme tutorial

[rendaw <7e9wc56emjakcm@s.rendaw.me>]

On 5/4/19 8:02 PM, amirouche@hyper.dev wrote:
> On 2019-05-04 08:08, rendaw wrote:
>> On 5/3/19 9:45 PM, amirouche@hyper.dev wrote:
>>> Hello!
>>>
>>>
>> (Whoops, replied with the wrong account.)
>>
>> Oh, this is great!  I've actually been putting together a small Guix
>> guide here:
>> https://gitlab.com/rendaw/blog/blob/master/how_to_guix_for_those_who_dont.md
>>
>>
>> It has a small Guile primer, but it doesn't go into depth or have any
>> hands on examples like yours.  My goal was to cover just enough so that
>> people could understand Guix configs (or at least 90% of them), so no
>> recursion, etc.  I'm glad you got into records, I just kind of handwaved
>> that away ("they're functions", not 100% sure this is correct either).
>
> That is good. The beginning looks like guix is not worthwhile and then
> you continue in the second page with an introduction to guile and guix.
> I find it nice actually.
>
> I spotted a minor error:
>
>   (system* (string-append #$openssl "/bin/openssl")
>            "genrsa" "-out" private-key "2048"))
>
>  
> https://gitlab.com/rendaw/blog/blob/master/how_to_guix_for_those_who_dont.md#running-executables
>
> Indeed you can run programs like that but in guix it is preferred to run
> with invoke, see the source :)
>
> Thanks for sharing!

Oh awesome, thanks!  I saw the recommendation to use invoke (in the
package guide?) but actually I'd like to know what the difference
between invoke and system* are... the code above was something I grabbed
from the Guix source somewhere (cups.scm?)

I just checked now (defined in guix/build/utils.scm) and it looks like
invoke raises an exception if the command has a non-zero exit, but
otherwise they're the same.

One more note for the guide I guess :D