diff --git a/libs/input/PrintTools.cpp b/libs/input/PrintTools.cpp
index 5d6ae4e..01f6bf5 100644
--- a/libs/input/PrintTools.cpp
+++ b/libs/input/PrintTools.cpp
@@ -17,6 +17,7 @@
 #define LOG_TAG "PrintTools"
 
 #include <input/PrintTools.h>
+#include <sstream>
 
 namespace android {
 
@@ -24,4 +25,20 @@
     return value ? "true" : "false";
 }
 
+std::string addLinePrefix(std::string str, const std::string& prefix) {
+    std::stringstream ss;
+    bool newLineStarted = true;
+    for (const auto& ch : str) {
+        if (newLineStarted) {
+            ss << prefix;
+            newLineStarted = false;
+        }
+        if (ch == '\n') {
+            newLineStarted = true;
+        }
+        ss << ch;
+    }
+    return ss.str();
+}
+
 } // namespace android