alternatives: initial feature

This feature allows you to set alternatives [1]. For example, like this: @$(call add,ALTERNATIVES,/usr/bin/xvt:/usr/bin/xterm) Also, in the config itself, targets for setting alternatives may already be predefined. For example, use/alternatives/xvt/% allows you to specify arbitrary alternatives for xvt: use/alternatives/xvt/xterm, use/alternatives/xvt/mate-terminal, etc. However, an alternative must be available. 1. https://www.altlinux.org/Alternatives

alternatives: initial feature
2f0cf575 · Anton Midyukov · 388c0fbb · 2f0cf575 · 2f0cf575 · 2f0cf575
Commit 2f0cf575 authored Mar 27, 2023 by Anton Midyukov
4 changed files
--- a/doc/mkimage-profiles.asciidoc
+++ b/doc/mkimage-profiles.asciidoc
@@ -54,6 +54,8 @@ include::../features.in/README[]

 include::../features.in/00example/README[]

+include::../features.in/alternatives/README[]
+
 include::../features.in/apt-conf/README[]

 include::../features.in/armh-mcom02/README[]

--- a/features.in/alternatives/README
+++ b/features.in/alternatives/README
+=== features.in/alternatives ===
+
+Данная фича позволяет задавать альтернативы [1].
+Например, так:
+
+  @$(call add,ALTERNATIVES,/usr/bin/xvt:/usr/bin/xterm)
+
+Также в самом конфиге могут быть уже преопределены цели для установки альтернатив.
+Например, use/alternatives/xvt/% позволяет задавать произвольные альтернативы для xvt:
+use/alternatives/xvt/xterm, use/alternatives/xvt/mate-terminal и т.д.
+При этом альтернатива должна быть доступна.
+
+1. https://www.altlinux.org/Alternatives
--- a/features.in/alternatives/config.mk
+++ b/features.in/alternatives/config.mk
+use/alternatives:
+	@$(call add_feature)
+	@$(call xport,ALTERNATIVES)
+
+use/alternatives/xvt/%: use/alternatives
+	@$(call add,ALTERNATIVES,/usr/bin/xvt:/usr/bin/$*)
--- a/features.in/alternatives/rootfs/image-scripts.d/99-alternatives
+++ b/features.in/alternatives/rootfs/image-scripts.d/99-alternatives
+#!/bin/sh -efu
+
+[ -n "$GLOBAL_ALTERNATIVES" ] || exit 0
+for alternative in $GLOBAL_ALTERNATIVES; do
+	candidate="${alternative#*:}"
+	alternative="${alternative%:*}"
+	alternatives-manual "$alternative" "$candidate"
+done
+
+alternatives-update