chore: update example to show how to split public inputs in bash (#6472)

examples/codegen_verifier/codegen_verifier.sh

@@ -16,11 +16,17 @@ nargo execute witness
 PROOF_PATH=./target/proof
 $BACKEND prove -b ./target/hello_world.json -w ./target/witness.gz -o $PROOF_PATH
 
-NUM_PUBLIC_INPUTS=1
+# Sanity check that proof is valid.
+$BACKEND verify -k ./target/vk -p ./target/proof
+
+NUM_PUBLIC_INPUTS=2
 PUBLIC_INPUT_BYTES=$((32 * $NUM_PUBLIC_INPUTS))
 HEX_PUBLIC_INPUTS=$(head -c $PUBLIC_INPUT_BYTES $PROOF_PATH | od -An -v -t x1 | tr -d $' \n')
 HEX_PROOF=$(tail -c +$(($PUBLIC_INPUT_BYTES + 1)) $PROOF_PATH | od -An -v -t x1 | tr -d $' \n')
 
+# Split public inputs into strings where each string represents a `bytes32`.
+SPLIT_HEX_PUBLIC_INPUTS=$(sed -e 's/.\{64\}/0x&,/g' <<< $HEX_PUBLIC_INPUTS)
+
 # Spin up an anvil node to deploy the contract to
 anvil &
 
@@ -31,8 +37,7 @@ DEPLOY_INFO=$(forge create UltraVerifier \
 VERIFIER_ADDRESS=$(echo $DEPLOY_INFO | jq -r '.deployedTo')
 
 # Call the verifier contract with our proof.
-# Note that we haven't needed to split up `HEX_PUBLIC_INPUTS` as there's only a single public input
-cast call $VERIFIER_ADDRESS "verify(bytes, bytes32[])(bool)" "0x$HEX_PROOF" "[0x$HEX_PUBLIC_INPUTS]"
+cast call $VERIFIER_ADDRESS "verify(bytes, bytes32[])(bool)" "0x$HEX_PROOF" "[$SPLIT_HEX_PUBLIC_INPUTS]"
 
 # Stop anvil node again
-kill %-
+kill %-

examples/codegen_verifier/src/main.nr

@@ -1,3 +1,3 @@
-fn main(x: Field, y: pub Field) {
+fn main(x: pub Field, y: pub Field) {
     assert(x != y);
-}
+}