diff --git a/gnu/home.scm b/gnu/home.scm index a9f0a469a5..4ddbafe412 100644 --- a/gnu/home.scm +++ b/gnu/home.scm @@ -1,5 +1,6 @@ ;;; GNU Guix --- Functional package management for GNU ;;; Copyright © 2021 Andrew Tropin +;;; Copyright © 2022 Ludovic Courtès ;;; ;;; This file is part of GNU Guix. ;;; @@ -27,7 +28,8 @@ #:use-module (guix diagnostics) #:use-module (guix gexp) #:use-module (guix store) - + #:use-module (ice-9 match) + #:use-module (ice-9 regex) #:export (home-environment home-environment? this-home-environment @@ -38,7 +40,9 @@ home-environment-services home-environment-location - home-environment-with-provenance)) + home-environment-with-provenance + + home-generation-base)) ;;; Comment: ;;; @@ -114,3 +118,21 @@ of HOME-PROVENANCE-SERVICE-TYPE to its services." (run-with-store store (home-environment-derivation he) #:system system #:target target))))) + +(define %profile-generation-rx + ;; Regexp that matches profile generation. + (make-regexp "(.*)-([0-9]+)-link$")) + +(define (home-generation-base file) + "If FILE is a Home generation GC root such as \"guix-home-42-link\", +return its corresponding base---e.g., \"guix-home\". Otherwise return #f. + +This is similar to the 'generation-profile' procedure but applied to Home +generations." + (match (regexp-exec %profile-generation-rx file) + (#f #f) + (m (let ((profile (match:substring m 1))) + ;; Distinguish from a "real" profile and from a system generation. + (and (file-exists? (string-append profile "/on-first-login")) + (file-exists? (string-append profile "/profile/manifest")) + profile)))))