Initial commit

src/include/quack_extension.hpp

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+#pragma once
+
+#include "duckdb.hpp"
+
+namespace duckdb {
+
+class QuackExtension : public Extension {
+public:
+	void Load(DuckDB &db) override;
+	std::string Name() override;
+        std::string Version() const override;
+};
+
+} // namespace duckdb

src/quack_extension.cpp

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+#define DUCKDB_EXTENSION_MAIN
+
+#include "quack_extension.hpp"
+#include "duckdb.hpp"
+#include "duckdb/common/exception.hpp"
+#include "duckdb/common/string_util.hpp"
+#include "duckdb/function/scalar_function.hpp"
+#include "duckdb/main/extension_util.hpp"
+#include <duckdb/parser/parsed_data/create_scalar_function_info.hpp>
+
+// OpenSSL linked through vcpkg
+#include <openssl/opensslv.h>
+
+namespace duckdb {
+
+inline void QuackScalarFun(DataChunk &args, ExpressionState &state, Vector &result) {
+    auto &name_vector = args.data[0];
+    UnaryExecutor::Execute<string_t, string_t>(
+	    name_vector, result, args.size(),
+	    [&](string_t name) {
+			return StringVector::AddString(result, "Quack "+name.GetString()+" 🐥");
+        });
+}
+
+inline void QuackOpenSSLVersionScalarFun(DataChunk &args, ExpressionState &state, Vector &result) {
+    auto &name_vector = args.data[0];
+    UnaryExecutor::Execute<string_t, string_t>(
+	    name_vector, result, args.size(),
+	    [&](string_t name) {
+			return StringVector::AddString(result, "Quack " + name.GetString() +
+                                                     ", my linked OpenSSL version is " +
+                                                     OPENSSL_VERSION_TEXT );
+        });
+}
+
+static void LoadInternal(DatabaseInstance &instance) {
+    // Register a scalar function
+    auto quack_scalar_function = ScalarFunction("quack", {LogicalType::VARCHAR}, LogicalType::VARCHAR, QuackScalarFun);
+    ExtensionUtil::RegisterFunction(instance, quack_scalar_function);
+
+    // Register another scalar function
+    auto quack_openssl_version_scalar_function = ScalarFunction("quack_openssl_version", {LogicalType::VARCHAR},
+                                                LogicalType::VARCHAR, QuackOpenSSLVersionScalarFun);
+    ExtensionUtil::RegisterFunction(instance, quack_openssl_version_scalar_function);
+}
+
+void QuackExtension::Load(DuckDB &db) {
+	LoadInternal(*db.instance);
+}
+std::string QuackExtension::Name() {
+	return "quack";
+}
+
+std::string QuackExtension::Version() const {
+#ifdef EXT_VERSION_QUACK
+	return EXT_VERSION_QUACK;
+#else
+	return "";
+#endif
+}
+
+} // namespace duckdb
+
+extern "C" {
+
+DUCKDB_EXTENSION_API void quack_init(duckdb::DatabaseInstance &db) {
+    duckdb::DuckDB db_wrapper(db);
+    db_wrapper.LoadExtension<duckdb::QuackExtension>();
+}
+
+DUCKDB_EXTENSION_API const char *quack_version() {
+	return duckdb::DuckDB::LibraryVersion();
+}
+}
+
+#ifndef DUCKDB_EXTENSION_MAIN
+#error DUCKDB_EXTENSION_MAIN not defined
+#endif