Reference: https://man.freebsd.org/cgi/man.cgi?query=md5sum
ifeq ($(shell md5 < /dev/null > /dev/null; echo $$?), 0)
HASH ?= md5
endif
-else ifeq ($(UNAME), FreeBSD)
- HASH ?= gmd5sum
else ifeq ($(UNAME), NetBSD)
HASH ?= md5 -n
else ifeq ($(UNAME), OpenBSD)
case "$UNAME" in
Darwin) MD5SUM="md5 -r" ;;
- FreeBSD) MD5SUM="gmd5sum" ;;
NetBSD) MD5SUM="md5 -n" ;;
OpenBSD) MD5SUM="md5" ;;
*) MD5SUM="md5sum" ;;
case "$UNAME" in
Darwin) MD5SUM="md5 -r" ;;
- FreeBSD) MD5SUM="gmd5sum" ;;
NetBSD) MD5SUM="md5 -n" ;;
OpenBSD) MD5SUM="md5" ;;
*) MD5SUM="md5sum" ;;