2 files changed, 16 insertions, 0 deletions
diff --git a/src/libutil/logging.cc b/src/libutil/logging.cc
index bb437cf1c..3cc4ef8f1 100644
--- a/src/libutil/logging.cc
+++ b/src/libutil/logging.cc
@@ -3,6 +3,7 @@
 
 #include <atomic>
 #include <nlohmann/json.hpp>
+#include <iostream>
 
 namespace nix {
 
@@ -24,6 +25,11 @@ void Logger::warn(const std::string & msg)
     log(lvlWarn, ANSI_YELLOW "warning:" ANSI_NORMAL " " + msg);
 }
 
+void Logger::writeToStdout(std::string_view s)
+{
+    std::cout << s << "\n";
+}
+
 class SimpleLogger : public Logger
 {
 public:
diff --git a/src/libutil/logging.hh b/src/libutil/logging.hh
index 108b5dcb0..18c24d508 100644
--- a/src/libutil/logging.hh
+++ b/src/libutil/logging.hh
@@ -78,6 +78,16 @@ public:
     virtual void stopActivity(ActivityId act) { };
 
     virtual void result(ActivityId act, ResultType type, const Fields & fields) { };
+
+    virtual void writeToStdout(std::string_view s);
+
+    template<typename... Args>
+    inline void stdout(const std::string & fs, const Args & ... args)
+    {
+        boost::format f(fs);
+        formatHelper(f, args...);
+        writeToStdout(f.str());
+    }
 };
 
 ActivityId getCurActivity();