Script to get list of links to changes since previous commit (#504)

* changes script

* full

scripts/get_changes_since_commit.sh

@@ -0,0 +1,45 @@
+#!/bin/bash
+
+# Generate a list of markdown formatted changes since the supplied `previous-commit`. 
+# You'd run this script like this:
+# ./scripts/get_changes_since_commit.sh --previous-commit 1d2e083acdd88d0829ad31e3a1725e3898565fda
+
+while [ "$#" -gt 0 ]; do
+  case "$1" in
+    --previous-commit)
+      previouscommit=($2)
+      shift 2
+      ;;
+    *)
+      echo "Unknown option: $1"
+      exit 1
+      ;;
+  esac
+done
+
+if [ -z "$previouscommit" ]; then
+  echo "Missing --previous-commit"
+  exit 1
+fi
+
+currentcommit=$(git rev-parse HEAD)
+
+# Get the commit messages between the previous commit and now.
+messages=$(git log --pretty=format:"%h %s" $previouscommit..$currentcommit)
+
+function geturl() {
+  echo "https://github.com/aptos-labs/aptos-indexer-processors/commit/$1"
+}
+
+cat <<EOF
+Full changes since $previouscommit (newest first):
+EOF
+
+while IFS= read -r line; do
+  sha=$(echo "$line" | cut -d ' ' -f1)
+  message=$(echo "$line" | cut -d ' ' -f2-)
+  echo "- [$sha]($(geturl $sha)): $message"
+done <<< "$messages"
+
+cat <<EOF
+EOF