Makefile: uses rsync(1), could this be optional?

[Steffen Nurpmeso]

Hello.

As a not-yet-tested low-quality Makefile suggestion, with modern
GNU tools and find(1)'s -printf, wouldn't the following code work
out gracefully in practice?  (Not subscribed.)

Thanks for Linux!

--- Makefile.orig	2022-01-15 19:33:59.337393371 +0100
+++ Makefile	2022-01-15 19:34:07.447393217 +0100
@@ -1260,8 +1288,17 @@ export INSTALL_HDR_PATH = $(objtree)/usr
 quiet_cmd_headers_install = INSTALL $(INSTALL_HDR_PATH)/include
       cmd_headers_install = \
 	mkdir -p $(INSTALL_HDR_PATH); \
-	rsync -mrl --include='*/' --include='*\.h' --exclude='*' \
-	usr/include $(INSTALL_HDR_PATH)
+	if command -v rsync; then \
+		rsync -mrl --include='*/' --include='*\.h' --exclude='*' \
+		usr/include $(INSTALL_HDR_PATH);\
+	else \
+		cd usr;\
+		find include/ -type f -name '*.h' -printf '%f %h\n' |\
+		while read f d; do \
+			mkdir -p $(INSTALL_HDR_PATH)/$$d;\
+			cp -P $$d/$$f $(INSTALL_HDR_PATH)/$$d/$$f;\
+		done;\
+	fi
 
 PHONY += headers_install
 headers_install: headers

--steffen
|
|Der Kragenbaer,                The moon bear,
|der holt sich munter           he cheerfully and one by one
|einen nach dem anderen runter  wa.ks himself off
|(By Robert Gernhardt)