diff --git a/backend/src/engine.cpp b/backend/src/engine.cpp
index 97116b0..2c803ff 100644
--- a/backend/src/engine.cpp
+++ b/backend/src/engine.cpp
@@ -315,7 +315,7 @@ std::vector<std::string> BookStoreEngineClass::ExecuteMOdify(
     return std::vector<std::string>({"Invalid"});
   // debugPrint("successfully lexed modify");
   // debugPrint("modify", new_ISBN, ' ', name, ' ', author, ' ', keyword, ' ',
-            //  price);
+  //  price);
   if (login_stack.empty() ||
       user_data_base.GetPrevilege(login_stack.top().first) < 3)
     return std::vector<std::string>({"Invalid"});
@@ -394,11 +394,19 @@ std::vector<std::string> BookStoreEngineClass::ExecuteShowFinance(
 std::vector<std::string> BookStoreEngineClass::ExecuteLog(
     const std::string &cmd,
     std::stack<std::pair<std::string, int>> &login_stack) {
+  static std::basic_regex<char> log_regex(
+      R"(^ *log *$)", std::regex_constants::optimize);
+  if(!std::regex_match(cmd, log_regex))
+    return std::vector<std::string>({"Invalid"});
   return std::vector<std::string>();
 }
 
 std::vector<std::string> BookStoreEngineClass::ExecuteReport(
     const std::string &cmd,
     std::stack<std::pair<std::string, int>> &login_stack) {
+  static std::basic_regex<char> report_regex(
+      R"(^ *report( +finance| +employee) *$)", std::regex_constants::optimize);
+  if (!std::regex_match(cmd, report_regex))
+    return std::vector<std::string>({"Invalid"});
   return std::vector<std::string>();
 }
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