Hi,
first let me have a meta comment. Your client seems to embed \r
characters (0x0D, CR) into your emails. Not sure if that is
intentional.
reza <r...@housseini.me> writes:
> Hi Guix
>
> I have problems of finding a reliable way to access the current
> directory from a guile script.
>
> My setup is the following: I have a channels.scm file and a manifest.scm
> file at my project root directory. Additionally I have
> .guix/modules/my-package.scm file describing my package, which I
> reference in my manifest file like
>
> (package->development-manifest (load "guix.scm"))
>
> where guix.scm is a symlink to .guix/modules/my-package.scm.
>
> Now in .guix/modules/my-package.scm I want to have the absolute path of
> my project root. I used to use
>
> (define %source-dir (string-append (current-source-directory) "/../.."))
>
> which works fine until you call something like this:
>
> guix time-machine -C channels.scm -- repl manifest.scm
>
> in the project root. This fails because current-source-directory returns
> the path to the manifest.scm file. Now I started to use
>
> (define %source-dir (canonicalize-path (dirname (dirname (dirname
> (current-filename))))))
>
> and this seemed to work fine until I included the package as a
> dependency into another package where it fails with the (not helpful at
> all) error message
>
> In procedure scm_to_utf8_stringn: Wrong type argument in position 1
> (expecting string): #f
>
> which seems to stem from the factthat current-filename resolved to #f
> and dirname threw an exception
> Now I am using
>
> (define %source-dir (or (canonicalize-path (dirname (dirname (dirname
> (current-filename)))))
> (string-append (current-source-directory)
> "/../..")))
>
> which covers my two needs, but it just feels ridiculously. Is there no
> easy and reliable way to get the path of the current script in
> guile?
I am not away of reliable way to get "path of the current script",
however for use in Guix, there is fairly simple pattern to get a root of
your repository. You just need to look for a known file unique to your
setup. I am using something similar to the following:
--8<---------------cut here---------------start------------->8---
(define %root
;; I am pretty sure this file will not be in any other directory.
(dirname (dirname (canonicalize-path
(search-path %load-path
"my-system/files/channels.scm")))))
--8<---------------cut here---------------end--------------->8---
And then I am just basing everything on %root.
Hope this helps,
Tomas
--
There are only two hard things in Computer Science:
cache invalidation, naming things and off-by-one errors.
