sha256sum -> sha256

Index: script/demo/download_demo_version.sh
--- script/demo/download_demo_version.sh.orig
+++ script/demo/download_demo_version.sh
@@ -80,12 +80,12 @@ else
     exit 1
 fi
 
-echo "$H2DEMO_SHA256 *h2demo.zip" > checksums
+echo "SHA256 (h2demo.zip) = $H2DEMO_SHA256" > checksums
 
 if [[ -n "$(command -v shasum)" ]]; then
     shasum --check --algorithm 256 checksums
-elif [[ -n "$(command -v sha256sum)" ]]; then
-    sha256sum --check --strict checksums
+elif [[ -n "$(command -v sha256)" ]]; then
+    sha256 -C checksums h2demo.zip
 else
     echo_red "Neither shasum nor sha256sum were found in your system. Unable to verify the downloaded file. Installation aborted."
     exit 1
