more features of easy install

easy_install.sh

@@ -1,9 +1,37 @@
 #!/bin/sh
 
-# first install rust
-echo "Installing Rust first..."
-curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
 
-# next install SciDataFlow
+if ! command -v rustc &> /dev/null; then
+
+ # expected MD5 of Rust
+ expected_md5="9457a47bb675d495b53d2ebbb757f63d"
+
+ # temp installer file
+ temp_file=$(mktemp)
+
+ # download Rust installer
+ curl --proto '=https' --tlsv1.2 -sSf -o "$temp_file" https://sh.rustup.rs
+
+ # calculate the MD5 hash of the downloaded file
+ calculated_md5=$(md5sum "$temp_file" | awk '{ print $1 }')
+
+ # verify MD5 hash
+ if [ "$expected_md5" != "$calculated_md5" ]; then
+ echo "MD5 verification of Rust installer failed! This is likely a version change.\nPlease report, and install manually from:\nhttps://www.rust-lang.org/learn/get-started"
+ rm "$temp_file"
+ exit 1
+ else
+ echo "MD5 verified. Installing Rust..."
+ sh "$temp_file"
+ fi
+
+ # remove the temporary file
+ rm "$temp_file"
+else
+ echo "Rust is already installed."
+fi
+
+# install SciDataFlow
 echo "Now installing SciDataFlow..."
 cargo install scidataflow
+