Revert "rework prereq check"

This reverts commit fba2ff31928b18364c1934654169806f5c800e23.

1 files changed, 14 insertions, 0 deletions

diff --git a/scripts/sha256sum b/scripts/sha256sum
new file mode 100755
index 000000000..e70973364
--- /dev/null
+++ b/scripts/sha256sum
@@ -0,0 +1,14 @@
+#!/usr/bin/env bash
+# This file is part of the OpenADK project. OpenADK is copyrighted
+# material, please see the LICENCE file in the top-level directory.
+
+if [ -x /usr/bin/sha256sum ]; then
+	/usr/bin/sha256sum "$@"
+elif [ -x /bin/cksum ] && [ $(echo | cksum -a sha256) = 01ba4719c80b6fe911b091a7c05124b64eeece964e09c058ef8f9805daca546b ]; then
+	# we assume the arguments are exactly "-c" or "-c -"
+	x=$(sed 's/^\([0-9a-fA-F]*\) *\([^ ].*\)$/SHA256 (\2) = \1/' | cksum -c -a sha256)
+	[[ $x = *FAILED* ]] && exit 1
+	exit 0
+else
+	shasum -a 256 "$@"
+fi