added reading start

simulator_SIC_XE/include/reader.h

@@ -1,4 +1,6 @@
-#pragma once
+#ifndef READER_H
+#define READER_H
+
 #include <string>
 #include <cstdint>
 
@@ -12,4 +14,8 @@ public:
     virtual bool readBytes(uint8_t* buf, size_t len) = 0;
     // read up to len bytes into a std::string; may return shorter string on EOF
     virtual std::string readString(size_t len) = 0;
-};
+    // read a line (up to newline), return empty string on EOF
+    virtual std::string readLine() = 0;
+};
+
+#endif // READER_H